Bottlehead Forum
Other Gear => Digital => Topic started by: xcortes on April 03, 2013, 01:07:49 PM
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My current responsibilities are keeping me grounded to my office close to 24/7 so I'm getting very little music and I hate that. And the future looks worse (this week the family is out so I'm squeezing some time to finish building the BeePre).
I have to solve the situation and analog is too much a hassle at the office (I tried!). I have never suceeded with digital but today I was very close to ordering an EAR CDP since I like TdP's products and he is an analog guy and a great designer. But hey guys, I'm a long time BH and I trust BH a lot.
And I always remember this from PJ that is veeery strong to me: "a) I HATE digital, and b) I'm buying John's design when it comes out even if I have to drive it with a $39 DVD player".
So I made the jump on a very good opportunity to buy what seems like a fantastic CD transport. It's gonna be shinny discs. Simple as it gets.
I brought the WE 755As to the office (sorry Blumensteins) and an M3 MQ Sex amp (not ideal 8 ohm for the 4 ohm WEs but who's counting).
I'm playing now a "Swenson/Rossi-mods" Toshiba DVD that isn't bad but, as usual with digital, tires after a while and the transport is noisy.
And I'm ready to buy the first BH DAC. Doc, you got the first order, firm. I know this product won't dissapoint me and I'm certain the price will be OK.
And someday in the future I'll build a Soul sister with MQ transformers at the input (B7 10k:10k Ni) and output (B7 8k:600 Co) and a pair of Co SR45s for which I have most parts. 'Cause contrary to my main system philosophy, for digital I think the mo' transformers the better to tame the digital beast.
Oh, and I promise I'll be good and build the DAC stock first.
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I have you on the list for production serial #001.
We are getting closer to being ready to take orders. I'm hoping for a prototype panel from FPE in the next day or two, which PB will build up in a manner based upon his rough layout pictured here, which is currently sitting on my desk. This layout is somewhat confusing because some of the components will actually be under the chassis, some on top.
What you see here is:
The DAC board in the front, inside an extrusion for shielding. This will hang under the chassis. There will be a slot on top with a socket for various forms of sample rate indicators and other cool things John is scheming on, and the USB, TOSLINK and Coax inputs are located there.
obviously the tubes will be on top, along with power switch, IEC power entry, and RCA jacks.
Those three chokes will be underneath, as will that board with the small power trans and power supply caps for the low voltage stuff.
The big power trans will be on top, with a PC board underneath for the power supply.
Not all of the firmware for high res and USB is done yet, but we should be playing 44k and 48K files via optical or coax as soon as we get it together.
And if you read this John, one of the extrusions is on it's way to you -
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One box. Good for the office!
No audio transformers. You were able to get rid of those since I remember John originally said a transformer after the dac followed by the IV resistor. Anyway I can use a pair of Co 8k:600 somewhere? (Ooooops, I said I was gonna behave).
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Doc,
Enough with the porno pictures. I can't wait to get one. Hope I can swing the cost. Any chance I can get one by the hour?
Brad
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I would love to get on the list, I think l have been waiting the longest :)
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Doc,
Enough with the porno pictures. I can't wait to get one. Hope I can swing the cost. Any chance I can get one by the hour?
Brad
Wow, I feel like I was just propositioned by a sailor! ;)
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I would love to get on the list, I think l have been waiting the longest :)
Not quite a long as me...hang in there, this prototype should be a big jump forward.
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One box. Good for the office!
No audio transformers. You were able to get rid of those since I remember John originally said a transformer after the dac followed by the IV resistor. Anyway I can use a pair of Co 8k:600 somewhere? (Ooooops, I said I was gonna behave).
Wasn't really a matter of getting rid of the transformers. I just did a lot of listening to transformer vs. resistor and found that the bass was a lot better to my ear with the resistor, and the mid and treble sounded very close. So that's what I decided to go with. I guess you could try the 8K:600 the other way around, DAC feeding the 600 ohm input with maybe a 133 ohm resistor across the 8K side so the DAC sees a 10 ohm load (if I did the math right, it is after all the martini hour). But I would require that you compare it to what we came up with, a 50 ohm resistor.
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As far as CD players, if you can find a Norh CD1, it is by far my favorite. Rock solid transport and integrated tube DAC. Is basically a CAL Delta transport and Alpha 24/96 tube DAC in the same box.
Pretty rare to come across though. Those of us who have them, almost never sell them.
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Put me on the list!
I blew my BH-DAC stash on the BeePre...too sexy to pass on...but I'm getting some long over due inheritance money, so I'm fully funded.
If anyone can do a DAC right, it will be designers that love vinyl.
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Had a nice long conversation with John Swenson today. We have a pretty exciting new development that could make the DAC USB2.0 and 192kHz compatible right out of the gate, offer more options for DSP, have a little more user friendly layout and construction, and several other improvements (including sounding a little better). John is working on a new layout for the DAC board and we hope to have it in house by month's end in order to keep our current goal of an early summer release in sight.
PB got construction of our latest prototype about 80% complete today and we hope to be giving it a listen Monday afternoon. This is not exactly what the final version will look like. It will be a bit more finished around the display board area and may have fewer tubes. But you can get a general sense of where we are at.
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Dan, any possibilities to include balanced output?
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Hello,
Long time reader, but first post on this board...
Sorry for my poor english, i'm french :P
While i'm quietly waiting for my Crack, you can count me on the list for this !
Just a little suggestion for a usefull feature : having the possibility to feed two devices with this DAC.
As numerous here i guess, i would like to use my DAC for both my speaker amp and my headphone amp.
A simple output switch would be a killer feature.
I hope my message is readable :-[
Have a nice day ;)
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No balanced output. The device is single ended, going balanced just adds stuff to the signal path.
You don't need a switch to connect something that has low output impedance and decent drive to two easy to drive loads at once. Just use a Y cable or drill extra holes and install more jacks.
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Out of curiosity, why the two power switches?
B
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Is that the 10" X 12" layout like the Stereomour? Looks great! Any idea of the price point? If this is to be released in the summer sometime I'd like to budget a "bottlehead" category in my financial planning.
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In this case one switch is for the DAC power supply and is intended to be left on between listening sessions to keep the circuit warmed up and sounding its best. The other is for the tube circuit so that one can shut the tubes off when not in use to extend their useful lifetime.
This is just a functional prototype and that's the kind of stuff that can change in the production prototype. There may be a few more switches added before we are done.
This chassis is 12 x 12 - subject to change also. Price is not yet determined. We have a slightly different design in the pipeline and will be comparing the two different prototypes around the end of the month. That will have some influence on size, pricing, layout, etc.
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Early summer? You could deliver it personally!
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You don't need a switch to connect something that has low output impedance and decent drive to two easy to drive loads at once. Just use a Y cable or drill extra holes and install more jacks.
Thanks for answer.
I was thinking about a switch precisely to avoid Y cable ^^
I have a few month to think about a customisation for multiple outputs...
Have a nice day :)
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In this case one switch is for the DAC power supply and is intended to be left on between listening sessions to keep the circuit warmed up and sounding its best. The other is for the tube circuit so that one can shut the tubes off when not in use to extend their useful lifetime.
Thank you, thank you, thank you
Andrew
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Good headway today. PB finished up the latest prototype and we got a few minutes of quite impressive sound. Two good steps forward besides sonics - the sample rate was being properly identified, and the TOSLINK connection was working perfectly, even with a rather recalcitrant Mac Mini that wouldn't talk to the previous iteration of the DAC without a reclock thru an external sound card.
Unfortunately some electronic component in our prototype power supply was fading out after a few minutes so we weren't able to do an extended listen. Staring at the sucker under the big magnifier on the lab bench for maybe 20 minutes convinced me that we needed to try the power supply we designed without it being connected to the DAC. Son of a gun, the negative rail was going south after a few minutes. Not exactly sure why, but it seems to be a filter cap issue. We have some new parts on order that should resolve the issue, and I will share our extended listening impressions as soon as we have the necessary adjustments completed.
In the few minutes that we were able to listen this afternoon there was definitely some magic happening. If you have heard the old proto, this is a step up.
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I like the phrases magic and impressive sound in the same post! Redbook rez?
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I'm really looking forward to being able to play my 96K and 192K files via USB! My library of hi rez tracks is growing and a DAC able to handle these is important.
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Can you tell us what tubes you are considering in the output stage? We realize that it may change still.
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Wow, sounds verry good and promising. if you can get 24/192 via usb 2.0 out of the gate, then I'll be much more intersted.
-- Jim
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Yes we were playing 44.1 files yesterday. Since we have a new board coming in about three weeks this prototype board is mostly just for working up our layout and was just set up for 44.1/48. The next one will be capable up to at least 192 and have USB2.0 in the basic configuration as well as SPDIF
At the moment we are using 6922s but that is subject to change as the chip we are looking at for the next board has different output requirements.
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Very cool, I am looking forward to the final product
Deb
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I'm going to hold tight onlooking at other DACs and wait for the this one. I will start looking at a media server based on what Jim R has been doing.
Ok, now I have some time to look for a turntable.
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Thanks for the answer. My Electrocompaniet emc1up just arrived. They build this transport starting from a Philips pro transport and taking care of vibrations "as if it was a turntable". Haven't seen her in the flesh but very soon. As I've said the simplicity of cds is paramount for me in this system. Having said that, in my experience, high rez is notably superior and someday I will add a server for the ever more recurrent late nights at the office.
Saludos
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Will the DAC be able to handle DSD files natively?
Thanks,
Dave
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We are using a PCM DAC chip, no native DSD.
Looks like I have sussed out our power supply issue. Gonna hook the DAC board back up to it and give it a spin after lunch.
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Audirvana is a great program I've been using to play music from my iTunes library. One of it's features is the ability to play DSD files natively or convert them to PCM. It also plays FLAC which most OSX programs don't allow. I've grown to like it much more than Amarra for its features and sound quality.
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Ready....
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One nice thing about these programs is that one can download free demos and test drive them in their own system.
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I've been using AudioGate for converting DSD files to PCM/96Khz.
These sound quite good in my system, though its hard to tell if its the format or the
mastering or recording quality that makes it sound so good. I also have some
ripped CDs at 44.1khz that sound very good and a lot of ripped CDs that sound pretty
bad - very compressed.
Thanks for the tip on Audirvana.
I guess we need something that will conver DSD or DXD to 24/192 PCM for the
Bottlehead DAC.
-Dave
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It's working and sounding very nice. I think I'm picking up better resolution with this DAC than the one we have been using the last couple years. Need to play it some more and break in the caps, but it's working well. Hopefully we can get the next (and hopefully final) version running soon...
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Hopefully we can get the next (and hopefully final) version running soon...
Holy shit! This is actually happening ...? I predict it will be ready by Xmas, which would be great!
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Any device with this level of complexity benefits from a beta test of sorts. It doesn't matter what label gets attached to the "real life encounter phase" it's always going to happen and the machine will typically end up better because of it. Right around Christmas is a good goal at this point, sorry, summer! I wonder, if the final version will retain the software/firmware update capability. The final I/V and the tube output stage should be able to handle any changes that happen further upstream, if and when they happen.
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I wonder if the new USB willwork with the SB Touch and EDO? I know that John Swenson has played with the SB products and would like to get his feedback on what source will work with the new USB input.
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As I'm new to DAC's for the most part a question for ya. Will I be able to have a computer plugged in via USB and a transport via something else at the same time? If so do you need to switch between them or will the DAC recognize where the signal is coming from?
Thanks,
Aaron
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There will be a switch to allow choosing USB or SPDIF input.
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Yes it will work with the SBT and EDO. The new USB is going to be UAC2, which means it can go up to 24/192. What Doc doesn't even know yet is that it is going to be multi-channel, so some time in the future we can offer a board that plugs into the extension port and connects multiple DAC boxes so you can get up to 8 channels over the one USB connection.
The downside of UAC2 is that it will not work out of the box with Windows, it will take a UAC2 driver, just like all the other UAC2 DACs out there now. It will work out of the box with Mac and Linux.
There are going to be three inputs, S/PDIF coaxial on a 75 ohm BNC, S/PDIF optical (TOSLINK) and USB (UAC2). There will be a switch to select between them. I don't have any plans to do autodetect, it is really difficult. Most sources don't actually turn off the carrier when not playing, so it becomes a task of detecting "silence", it's not so easy to do reliably without unintentional source switches.
John S.
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John,
Thank you for the information. I have been thinking of dropping the Touch and getting either a Mac Mini or building a Linux based computer, but think I will keep the Touch and power supply I built based on your design and use it with the Bottlehead DAC via the USB out.
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John,
Thanks for the information. I am excited for the DAC, I am sure it will be awesome!
Deb
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John,
will 24/192 be available over S/PDIF?
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Yes, 24/192 will work over S/PDIF coax. I'm using the fastest TOSLINK receiver I can get, which should allow 192 via optical, IF the transport supports it.
Many devices use the cheaper slower optical modules which won't work for 192, so many transport designers limited their optical out to 96. So IF yours supports 192 over optical it should work as well.
John S.
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Support for Interger Mode would be nice too, many of the audiophile players now have the ability to utilize DAC's which support it.
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Wasn't really a matter of getting rid of the transformers. I just did a lot of listening to transformer vs. resistor and found that the bass was a lot better to my ear with the resistor, and the mid and treble sounded very close
At the very beginning of this project John Swenson mentioned the transformers worked very well as low pass filters. May i ask if the current iteration is completely filterless or are you implementing some analog filter?
Thanks
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The version we are using this week uses a cap as a simple 1st order filter. I found, as usual, that a line level transformer didn't give me the best bass.
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"The version we are using this week". Classic!
Thanks
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John shot me an email last week with a status report. Looks like about four weeks before we have a prototype of the latest version running.
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Sounds like some premium parts are going into this thing like the BeePre.. I like it...
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Forgive me if it has already been answered and I missed it.
Will the USB input be asynchronous?
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I'm away from my notes today. There are two pretty big windfalls in my yard that have been there for weeks, PB loaned me a chainsaw, and it's sunny, so I'll be playing gardener today. I believe that John has something he feels is a superior way to deal with USB and hopefully he will weigh in on that when he has some free time.
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Has a list of all the supported sample rates been posted? I cant remember seeing them all listed yet.
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John has posted that the DAC will support rates up to 24/192 via USB and coaxial. As for optical he is working on supporting the same rate, but that does not seem to be confirmed. Not sure about the other sample rates.
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The most common sampling rates are: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz and 192 kHz. I had wanted to know if all of these are supported since I own digital files for each of the above and hoping the DAC can handle them with having to upsample to 192 kHz.
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Yes, it will be able to do all of those sample rates as well as 176.4
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i've been looking into making my 2 channel setup into a 5.1 and it looks like this DAC will be capable of playing back my multi channel files. Would I need to purchase 5 separate kits to do this?
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It's a stereo DAC, so for six channels you would need three kits. Be advised that it may be a while before we have this ability to parallel three or four DACs available, i.e. it may not be ready in the first release. The beauty of the auxilary port that John mentioned is that we can add new features as we have time to develop them and use that port to implement them.
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Yes, the USB input is asynchronous UAC2.
S/PDIF coax and USB will handle 44.1, 48, 88.2, 96, 176.4 and 192.
The S/PDIF optical input will just barely have enough bandwidth to handle 192. Not all sources will transmit 192 over optical, so it's more a case of what the source will transmit. The cable is also important here, since 192 over optical is right on the edge of what's doable a not so good cable can muck it up. (do NOT ask me for a list of cables that work, I do not have such a list)
I'm designing the USB input to handle 8 channels, but the hardware and firmware to couple multiple DAC boxes together will not be available at first, it's going to take some time to get that ready.
John S.
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This has gotten me dreaming about a stupidly expensive (for me), but magically delicious dream set up of Bottlehead DAC feeding a Mainline, a BeePre, and a pair of Paramounts feeding my HD800s and some Blumenstein Orcas.
A whole lot of wood, tubes, and point to point wiring.
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Order it all at once and I'll cut you a heckuva deal! ;)
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This all sounds pretty cool. I guess you won't know much the DAC kit will cost until you are done prototyping and have a kit ready to go.
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Order it all at once and I'll cut you a heckuva deal! ;)
If things go well for me the rest of the year, you might get that order ;D
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This all sounds pretty cool. I guess you won't know much the DAC kit will cost until you are done prototyping and have a kit ready to go.
Yes, we need to get the next iteration done before we can figure out pricing, because it is enough different than the current one that some component prices are very different - hopefully in the right direction, i.e., less expensive.
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I don't think anyone dares ask at this point, but hell, why not: Doc, if you could give a realistic estimate on this being done (with price and order page up) what would you say?
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Sometime in summer, if I had my way.
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Any chance of the DAC having volume control so that it could be run directly into an amp? With the recent introduction of the BeePre and Submissive, I'm guessing the answer is no, but maybe this is one of the surprises? Thanks.
Gerry
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Bottlehead has the new passive volume control called the Submissive that should fit the bill.
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Yes, Brad has it right. Submissive would be the volume control you are looking for.
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Due to my lack of knowledge, I'm going to ask a stupid question. Is the Submissive required between the DAC and all amps, or can you leave it out if the amp has its own volume control?
Specifically, I am interested in getting the DAC and Crack for use at my office.
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mSummers,
You will be able to use the DAC directly into the Crack.
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Thanks, Brad! I was hoping that was the case.
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Any update? How's this looking?
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Count me in! Can I please have serial number 007? 8)
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I recently picked up a squeezebox 3 on ebay cheap...it had an upgraded ps already. So it sounds pretty good but i decide i wanna do the analog mods (as i dont have a dac anyway). I crack it open and whoa its been modded already! Looks like professionally modded too. But only to the digital side. So i need a bh dac now! Count me in!
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We're headed on vacation next week, but when we get back we will be working on getting the next prototype manufactured.
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Count me in on the Bottlehead DAC I've gotten DAC fever since building the Raspberry Pi Squeezebox and I know you guys will do it right.
Will it have a headphone jack?
John
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I'll order one as soon as it is available also!
Debra
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I'm interested, too...JohnEH's RPi adventures have got me networking music all over the house...need at least one great DAC for the main system...
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Want!
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I'm in for one as well
bryan
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I've been trolling around looking to upgrade my digital front end. This definitely seems worth the wait!
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Hi Guys,
I have gone through the thred but can not see any indicitave pricing? any guess, i know without a final BOM its not going to be exact, just need to make sure i can get approval from the minister of Finance ;)
Thanks
Lachlan
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Here's where we stand -
John has the new design pretty much developed and ready to prototype. We ran into a hitch in that the chip he wants to use for USB seemed to be out of stock everywhere. He pursued that before going forward and it now looks like there are plenty, but everyone in the U.S. is temporarily out of stock. So it will be a couple of weeks before we can have the new prototype board manufactured.
As to price, that is still up in the air until we have those boards made. There are also two possible scenarios in terms of how it is packaged that could make a big difference in the price. We won't know which version we will be selling until we hear the prototype board.
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Thanks for the update Doc. Add me to the list of those patiently waiting for this kit.
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Put me down for one of the kits when they are ready to ship.
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Expendable income is coming to an end, Sept. 1. So I probably won't get there.
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Another me too post, but I'm also looking for a high quality DIY DAC. Count me in when they are ready to ship.
;D
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I own three DAC's. One sits on the shelf - it's older and doesn't do much for me but the other two are in production. The Lite tube Dac sits between a Squeezebox III and my Crack :o (it's not as painful as you might think!), the Stello DA220 from the other digital out on the Squeezebox to my main system.
I'm definitely in for one of Doc's creations! Sign me up! I can't wait. ;D
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John just sent me some pics of the newest prototype board. Should be here in a week or two.
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Post some teaser pics!! ;)
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Good news! The headphone jack out of my mac mini is killing me. I cant get squeezeserver to work on the mac with my sb3:(
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Does the balanced out on the DAC use the double XLR connectors? I just picked up an electrostatic amp with the 3-pin XLR inputs and want to be able to feed it a balanced signal.
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John just sent me an email saying that he has the SPDIF and the USB inputs working on the latest prototype, just needing a couple more tweaks. Once that is finalized he will get his special digital filter working and hopefully we should have a prototype to audition in few more weeks.
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Cool. If that prototype meets expectations would the next step be to move to making it available?
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John designs the digital to audio board and does the programming. We do the output design, power supply and packaging. Once we have the board we will be able to assess how much more might be involved in getting it to market.
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John designs the digital to audio board and does the programming. We do the output design, power supply and packaging. Once we have the board we will be able to assess how much more might be involved in getting it to market.
That can't be more than 30 minutes of work, can it?
;D
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Sir you woefully underestimate that amount of work..you forgot the mandatory 15 min food break and 15 min employee ergo stress relief break. You shouldn't be flaunting state laws :)
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I forget if this has been discussed, but what are the chances the BH DAC will be able to function as a network player, too?
Explanation: I have one main computer running J.River with LOTS of FLAC on it. I'd like to be able to access that FLAC in different parts of the house, via ethernet (or wireless). But I need something at the other end to receive the signal, and to send it to a DAC without compression and gaplessly (that, apparently, is where even great products fail). If the DAC itself could receive and process the signal, even better.
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It's a DAC, not a player. It has USB and SPDIF inputs. You would need a Squeezebox or Alix box or an old Mac Mini or other inexpensive player that is ethernet/wifi capable to run into the DAC via USB or coax/TOSLINK.
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It's a DAC, not a player. It has USB and SPDIF inputs. You would need a Squeezebox or Alix box or an old Mac Mini or other inexpensive player that is ethernet/wifi capable to run into the DAC via USB or coax/TOSLINK.
That's what I figured. Just checking.
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I'm taking a short break from slaving away at this and I thought I'd give an update, this is sounding incredible, it is the best sound I have ever heard coming out of a DAC, and it doesn't even have the tube stage yet. I'm listening to an album that I have on both vinyl and CD and am now hearing loads of stuff I have never heard before. This is just plain stunning.
If I had to characterize the sound I would say it's missing stuff: glare, distortion, noise, edginess, grunge, all that stuff just seems to be gone leaving the music in all its glory behind.
Now that I have you all drooling I better get back to working on it!
John S.
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Your description is killing me!
Are we looking at a Xmas ship date possibility? Please! (oh, and a price under $1k)
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It's a DAC, not a player. It has USB and SPDIF inputs. You would need a Squeezebox or Alix box or an old Mac Mini or other inexpensive player that is ethernet/wifi capable to run into the DAC via USB or coax/TOSLINK.
So its going to be network, USB, and SPDIF?!
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No, just USB and SPDIF.
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Maybe a question already answered: will it play DSD files native (either ASIO or DoP)?
Best,
John
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John,... one step at a time!
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...says Mr. "So it will be network compatible?"
:P
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I was just askin! - cuz I was cornfused!
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Quit huffing flux fumes, and things will be much clearer... ;D
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Oops...I know, I know. Sorry. Perhaps we could start a thread on "What I Want In A DAC?" and all post a never ending set of wishes, each more detailed and hypothetical than the last? ;) J/K
Best,
John
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Oops...I know, I know. Sorry. Perhaps we could start a thread on "What I Want In A DAC?" and all post a never ending set of wishes, each more detailed and hypothetical than the last? ;) J/K
Best,
John
Oh lets, Ill start. How about soon ;).
For the last few years, I have resisted buying more than a few commercial DAC's, thinking Ill wait for the Bottlehead DAC.
In the mean time I have made due with an assortment of kits and other bits, from eBay and wherever.
Learning to solder insanely small pitch SMD chips.
Ripping out op amps and kludge in, entirely the wrong line transformer, that happened to be on hand.
Recognizing the tacked on "tube" stage from, negative supply for grid bias, direct coupled...
hmm, might have another look at that.
I am having no fun at all and am not learning a thing so hurry up...John 8)
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The problem with that is what you want and what you will pay for are different things.
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PS "J/K" means "joke" in case there is any worry that I was being serious....my apologies stand and are extended just in case!
John
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I'm a computer cripple. I absolutely refuse to text. If you want to converse with me, call!
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To all you waiting patiently (?) here is a quick update:
both USB and S/PDIF are working very well. The USB is working up to 384, but the S/PDIF at the moment is only going up to 96. I plan on it going to up to 192, but it will take a little bit of work to make that happen.
The sound quality is absolutely amazing, right now I'm listening to it with external software upsampling to 352 with my custom filter paramters, the results get sent to the DAC chip with it's own internal filter turned off so its just my filter in the path. This is a whole new realm of experience. I'm listening to an album I've had for 20 years and am hearing things I have never heard before! It is stunning.
My next task is to get that filter working inside the DAC so you can use it with any input/sample rate.
As to the question of DSD, no it does not do DSD. The recent resurrection of DSD has come about during the development of this DAC, so it was not part of the specification.
I HAVE built a really good DSD DAC, and have been comparing the two and I can say that the BH DAC with my custom filter sounds very similar to the really good DSD DAC.
I have been coming up with a scheme to add the DSD output DAC to the aux connector, so there MIGHT be a DSD add on board later on.
I'm really hoping to get the prototype to Doc very soon.
John S.
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That answers it! John is for real! Thats the SHIT! (spelled the way it sounds)
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Thank you, John S, for that VERY exciting update!
Best,
John
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Any update?
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The new prototype board is shipping to Doc tomorrow!
There were some very difficult tasks in the last few weeks. The S/PDIF subsystem and the USB subsystem have very different architectures, getting them merged together was a tough task.
The digital filter in the FPGA had some problems as well, I found out it took two clock cycles longer to compute the filter than a sample takes, not good! (BTW this sounds really weird!) So I had to shrink the filter a little bit, fortunately there were some zeros at the beginning and end so I could shrink it a little, but then it wasn't a power of two. Now I know why they always make these as a power of two. The memories always come in powers of two, but try getting the filter to work when you have 1776 taps, whew that was a mess, but it is all working great now.
For those few that haven't heard my thoughts on digital filters, a quick synopsis: As far as I know all digital filters inside DAC chips use special DSP "tricks" to get really good spec sheet numbers at low cost, BUT these tricks wreak havoc with the "musicality" of the sound. This is why people like NOS DACs. BUT with a NOS you still have the aliases which cause a "dirty" sound. So what I am doing is relaxing the requirements of the filter, so it doesn't have to meet those insane numbers in the DAC spec sheets, the result is I can implement a simple filter that fits in an inexpensive FPGA.
The result is something most people have never heard, the musicality of NOS without the "dirty" sound of the aliases. It's simply stunning. Listening to your favorite music with this filter is a whole new experience.
Thanks all for your patience, this is really coming together now, it should be well worth the wait.
John S.
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Totally psyched!
Is this it for your side of the thing, John? If so, I imagine we're very close to getting to actually order it.
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It will be refreshing to have someone like John to give our curious minds something to chew on. Not just cliche sounding talking points.. Ex. min phase, dither?
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There is still more to do. This was a prototype board, I found six hardware issues which took a number of "red wires" on the prototype, I have to redo the board to incorporate these. One of the big problems was the startup of the XMOS processor, it turns out you have to have a specific sequence of voltages coming up and reset pulse. Unfortunately these requirements are not listed in the spec sheet, they are in a separate app note. Unfortunately I missed that when I designed the board. It's very easy to design a circuit to implement the requirements so it's not a problem.
One thing I'm changing is the "aux interface". I originally had a hardware interface using the FPGA and I was writing a protocol to send stuff over it. But Once I got working with the XMOS processors I'm throwing that out and using their Xlink interface which is specifically design to talk between chips. The interface and protocols are already built into all their processors. This makes it really easy to implement add on boards to do all kinds of things. One neat aspect of this is the remote processors can booth themselves over the Xlink from the "master" so you don't even have a way to program the remotes, they just program themselves over the link.
So there is some work still that I have to do, but all the basic functionality is in this prototype so Doc and company can start working on the tube output stage and floorplanning the top plate etc.
As to buzz words, the filter is intermediate phase. A linear phase filter has equal amounts of pre and post ringing but fairly short amount of time in each. The minimum phase has no pre ringing, but in order to get the same over all similar functionality it has to have a much longer amount of post ringing. The intermediate phase splits the difference and has a small amount of pre ringing and post ringing that is a little bit longer than linear phase but much less than minimum phase. This is also deliberately a short filter, that means the amount of time it spends ringing is a very short amount of time compared to other filters. The tradeoff is that the ultimate amount of alias reduction is only about 80db, whereas those in modern DAC chips are going to 130 db or more. This is the tradeoff I mentioned, by not aiming for nearly as much ultimate image rejection I get a filter that sounds much better.
There is no dither involved, it simply i not needed in the DAC.
Lets see, other buzz words, it has ground plane isolation with special high quality isolators on the signals. This does a very good job minimizing the ground plane noise from the digital chips from getting into the analog side of things. This gives a marvelous very "black" background. It also significantly cuts down on the outside world affects such as source component interaction and cable affects. It doesn't completely eliminate them, but it does significantly reduce these interactions. For example I have been listening to all three inputs (S/PDIF coax and TOSLINK and USB) and cannot tell hardly any difference between them. There are some very slight differences, but they are very small and hard to determine. There is only a very tiny difference in sound with different source components (different computers, OS etc, at least the ones I have on hand) I've spent a lot of work trying to decrease these sensitivities and I think I've done a pretty good job.
John S.
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Much appreciated John! - all imputs sounding similar is quite an accomplishment. Will look forward to the final product!
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The latest DAC arrived safe and sound day before yesterday. We have a little work to do to figure out what happened to the TOSLINK receiver (or maybe the TOSLINK output from my Mac Mini), and thus I have been listening exclusively via the most important input - USB.
My initial reaction was - YES! It is a very good DAC. The midrange clarity and depth was the first thing that struck me. John is very generous in his complements of the built in filter included with the DAC chip (which is in fact quite good) but his filter pretty soundly whups it in terms of easy presentation and a sense of dynamics. Bass kicks ass and treble is very smooth and open.
The DAC also seems to shift sample rates with ease. I have listened up to 192kHz so far and it's all really nice sounding with 44K sounding super clean and dynamic too.
Note that this is all without a tube output. It does of course really have a tube output, in the form of the tube preamp it is playing into. Thus we will probably offer the DAC without a tube stage initially to keep the price as reasonable as possible and maybe offer a tube stage later as an upgrade - if it is deemed an upgrade....
Nope, don't have a release date. Nope, don't know the price yet. Nope, not ready to share in-depth details of the components used. We need to work out layout, power etc. But I will share a release date and pricing as soon as we are ready to.
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Cool!
So the tube output stage would be a kind of pre-amplification? Why or why not would this be inessential? Can you explain what the difference with and without would be, especially if one already has a tube line stage such as the Quickie.
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Doc B. is saying that the DAC doesn't need a tube output stage, that's all. (You plug the DAC into your preamp/integrated)
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Doc B. is saying that the DAC doesn't need a tube output stage, that's all. (You plug the DAC into your preamp/integrated)
I understand, but if it's not needed why was it initially planned with one? Would it also have doubled as a headphone amp or would it have been to compensate for those who would only be using a Crack or SEX?
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Originally, the first couple of prototypes needed the extra gain, this one doesn't.
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Originally, the first couple of prototypes needed the extra gain, this one doesn't.
Got it. Definitely good news if it means just as good and at a lower price!
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The Bottlehead Dac evolved into the Bottle-less Dac :)
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Just a small update - we have started to compare running the DAC protoype with an inexpensive wall wart vs. battery vs. a pretty hefty linear supply. Still need to do some more evaluation before I have a definite plan in mind, but it's quite possible that we will suggest battery power as one good sounding option, supply parts with the kit to make your own power cable to hook the battery up to the DAC and suggest some sources for a 6V SLA battery and charger (we don't want to deal with the regulations regarding shipping batteries). The current draw of the DAC is estimated at around 400mA, so a $10-$15 12AH SLA might last 30 hours per charge. That's all hand waving, not hard numbers.
We're also working on the layout. Hope to have more to offer about that in the next week or two. As the DAC is breaking in it's sounding very, very nice, and John's digital filter sounds great.
Due to the level of circuit sophistication the pre stuffed boards for this DAC are complex and quite expensive. I'm wrestling a bit with the pricing now that we have the project fairly well developed and I think the price will be under $1000. Probably not much under but we're squeezing it as hard as we can, short of hurting the sound.
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Do you think it might be ready for Christmas?
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Is there a possibility that you all might release a base version and a kitchen sink version or is the soft plan to release upgrades along the way?
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The plan is still coming together. Frankly it sounds so good that I don't think it needs much "upgrading" besides figuring out these differences in the power supplies. So it might be power supply options and display options that we offer. I am hoping to have it ready by the end of the year if not sooner.
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Thanks Dan! If a tubes output isn't a priority anymore then maybe a tubed nixie display will take its place :)
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Can't wait for this to be released. Sounds like it will be awesome! I will order as soon as it is available.
I would love the nixie tube display! it would match all the clocks I have built
Debra
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We will probably do a pre-order on this kit, because we have to buy a very large quantity of the DAC boards to get a price that is affordable. Thus we will need to cough up many thousands of dollars in advance to cover the order. We'll probably need around 15 to 20 pre orders to make it happen. When I have a sense of the timeline on delivery and a firm idea of the price I'll let everyone know.
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Add another name to that pre-order list - I can't wait!!
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I've always wanted to have a Nixie tube display with this (definitely an add on), the idea is that it could tap off the tube power supply, but if it doesn't have a tube stage, no tube power supply so we would have to have a separate supply for the Nixie tubes. That's going to make it a lot more difficult. Doc will have to figure out how he wants to deal with that!
John S.
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I've always wanted to have a Nixie tube display with this (definitely an add on), the idea is that it could tap off the tube power supply, but if it doesn't have a tube stage, no tube power supply so we would have to have a separate supply for the Nixie tubes. That's going to make it a lot more difficult. Doc will have to figure out how he wants to deal with that!
John S.
Curiosity got the better of me so I just googled Nixie displays - how very cool! Not sure I have the desk space for it in addition to all the other gear, but maybe someone will come up with a Bottlehead rack mount system!!
Just kidding....
...or am I?
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I think it could be as simple as a separate little transformer and power supply if we go battery. If we go linear supply we can just make the HV for the nixies available from that. Don't worry John, I want those nixies too!
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If the DAC is designed to have a plug in display card on top of a standard BH type chassis a nixie tube like the IN-12 would probably work, and they are readily available still.
Debra
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I'll do a preorder. Can't wait for this one. Hope I don't have to solder any expensive parts ;-)
Thanks for all the work on this DAC.
-Dave
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I have been following this thread with interest and am definitely considering picking one up. It would be a nice anchor for the Crack/Stereomour system I will be building over the next few months. I'm wondering how much of it will be DIY? Will it primarily consist of stuffing a few PCBs? I am also wondering if it is going to be shrinking down from the 12"x12" chassis that had been mocked up?
Thanks for the hard work!
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The main board is going to come fully assembled, it is full of super small, super fine pitch parts that are essentially impossible to solder by hand - even with a hot air soldering station.
There will be some adapter boards to go between the main board and the connectors on the top plate, these may or may not need some parts soldering, not quite sure yet.
Then there is whatever it takes for power supply.
The upshot is that it should not be a difficult build. Probably a few connector soldering and mounting boards and running cables between connectors on boards.
John S.
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I am also wondering if it is going to be shrinking down from the 12"x12" chassis that had been mocked up?
The size is indeed shrinking. When we are prototyping a circuit that may go through a bunch of revisions, we like to leave a lot of space to allow for great flexibility.
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Thanks for the great answers. Very, very tempted. I'm a local and I'm planning on driving up in a month or so to pick up my Stereomour kit, perhaps I'll get to listen to the prototype???
Again, thanks.
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I'm already saving up for this one. Nixie tube display would be sooooo cool!
I've been looking at upgrading from my Dacmagic and was thinking "I wish Bottlehead had a DAC kit." Low and behold, it's just a few months away. Can't wait!
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Any updates on DAC progress?
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Waiting for parts to come in to put together a functional prototype. Battery power seems to sound a little better than our iron heavy AC supply, so we plan to experiment with a rechargeable battery supply in the chassis.
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I am curious. If in fact you are to use battery power, how many cells will be needed?
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So far we are thinking a single SLA. I'm just putting the finishing touches on a custom charger that will be regulated specifically to one battery we have in mind.
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Thanks. the reason that I ask is that if I were to buy this product, I would consider a battery pack that could run it and the Quickie at the same time. Just a thought. Of course, the battery pack would have to be adjusted to acommodate these new requirements.
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Thanks for the update Doc & PB.
Will the Dac be strictly battery when playing and charging in the off cycle?
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I can't say for sure yet if it will make the cut, but it is the idea we plan to try. We should know more some time next week.
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Is everything besides the power pretty much set to go?
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Any idea yet on how much ventilation is going to be needed around the DAC?
My 28 year old CD player needs a break! :)
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Sooo, any more teasing photos or tidbits of information for us? :D
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PB has worked up a battery charging circuit. We're awaiting some new batteries in order to test how much play time we get from a full charge. The ones we have around are pretty long in the tooth and not holding charge too well.
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Witchcraft. I wanted diode tubes and iron and ominous humming noises when i flick the switch, not a freaking iPod :D
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I think he wants a Jacob's Ladder on the power supply.
It looks cool but will give you headaches.
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I spend far too much time checking this thread. But I have to have something outside career and family to keep me in anticipation. I'm that boring, yes.
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We have worked out what should be the final small revisions to the DAC board. John will be working on getting these turned into a final prototype board in the next few weeks. Our battery supply test is on hold for a bit as we have had a setback with the existing prototype due to my trying to kludge together some temporary cables that seem to have killed our existing prototype. Yes, it was a very clever $1500 mistake that has thrown us behind maybe another four weeks. And people are always saying to me, "Doc your job must be so fun."
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Sam,
Just set the forum as your home page (I did). Then when you open your browser click on Unread Topics. If there is an update it will show up there.
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Sam,
Just set the forum as your home page (I did). Then when you open your browser click on Unread Topics. If there is an update it will show up there.
I do use the unread topics thread, but is find myself lying in wait for new posts. That's what I mean by anticipation. Lol
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Hey Doc, I have a battery supply for another project. It uses a CTEK US 800 charger to keep the battery topped up, it works very well...John
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What is the purpose of the batteries in the DAC circuit?
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It eliminates all AC. AC can cause hum. The electronics run on DC anyway.
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What is the purpose of the batteries in the DAC circuit?
The battery so far has sounded much better than the other supplies we have tried.
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Assuming you are using a battery as a cleaner power source, how you are going to implement a charging circuit without introducing the noise you were trying to avoid in the first place? I'm sure there is a simple way to do it, i'm just curious to learn...
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The on/off switch changes from disconnected from the charger (on) to connected to the charger (off).
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Ok, that made me laugh out loud. What's that saying again "keep it simple, stupid" :)
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I have an Ack! dAck! that has a four pole double position power switch. In the on position the two 12V batteries supply plus and minus 12V to the DAC, the charging circuit is totally disconnected. In the off position it connects the batteries in parallel and to the charger, the DAC circuit is disconnected.
You asked a technical question. It takes a technical answer.
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Thanks Grainger, i understood you the first time, my comment was in reference to the elegant simplicity of the solution.
My mind was trying to devise clever circuitry to separate the charging supply from the output when the answer was a DPDT switch, hence keep it simple.. :)
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Sorry!
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi244.photobucket.com%2Falbums%2Fgg7%2FGrainger49%2FSmiles%2FCorrected.gif&hash=89e1a80c0c6be2c0ddb28d3813ea9c4aaafdfcb2)
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Not at all, thank you for be so helpful ;)
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Well, thankfully John saved my a** by managing to repair the prototype board we blew last week. We're still not taking orders, but here is a photo of the most recent prototype that we have been playing with. This is 90% of the way to what the final will look like, save for some changes to the positioning of the various ports and slots. The panel is 6" square. The light at the front is the charging light. When on, unit is charging, when off, battery is fully charged. The switches are on/charge, USB/SPDIF coax/TOSLINK, and filter selection (that on the chip or John's awesome sounding software filter). The little slot behind that is where the optional sample rate display goes. That's a heat sink for the charging circuit at the left center, The screw heads in the middle hold the battery under the chassis, and I think the rest of the stuff is pretty self explanatory. Some of this may shift around and there will be one more slot for "accessories" to be determined in the future - that's why I say it's 90% like the finished version.
Good news is that it sounds quite good even with the charging circuit active. Great news is it sounds fabulous running off battery only. We are exploring the notion of a standby mode that keeps the board on and warmed up while the battery trickle charges, for those who like to keep their SS gear on all the time, and possibly a fast charge mode for those who are impatient and don't mind replacing the SLA battery more often.
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Dan,
This sounds really encouraging! I just recently read through this entire thread and I have to say that I'm really impressed and curious to hear it -- it's got bottlehead written all over it!
-- Jim
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What about the possibility of a second battery...charge one while the other is used? Are would that be necessary?
Got credit card in hand...just give the word :D
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Interesting! I see a Shielded Power Cable. It looks much like the one I built with the Bottlehead Power Cord kit.
What do you mean " . . . sounding with the charging circuit active"?
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Nice to know the package fits on a manageable 6" x 6" plate rather than the larger previous versions.
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Well, thankfully John saved my a** by managing to repair the prototype board we blew last week. We're still not taking orders, but here is a photo of the most recent prototype that we have been playing with. This is 90% of the way to what the final will look like, save for some changes to the positioning of the various ports and slots. The panel is 6" square. The light at the front is the charging light. When on, unit is charging, when off, battery is fully charged. The switches are on/charge, USB/SPDIF coax/TOSLINK, and filter selection (that on the chip or John's awesome sounding software filter). The little slot behind that is where the optional sample rate display goes. That's a heat sink for the charging circuit at the left center, The screw heads in the middle hold the battery under the chassis, and I think the rest of the stuff is pretty self explanatory. Some of this may shift around and there will be one more slot for "accessories" to be determined in the future - that's why I say it's 90% like the finished version.
Good news is that it sounds quite good even with the charging circuit active. Great news is it sounds fabulous running off battery only. We are exploring the notion of a standby mode that keeps the board on and warmed up while the battery trickle charges, for those who like to keep their SS gear on all the time, and possibly a fast charge mode for those who are impatient and don't mind replacing the SLA battery more often.
Awesome. There is a lot of space to vinyl wrap that chassis and be very creative. I'm gonna start working on something now to the tune of 6 x 6. Can't wait.
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6X6, I like that. I was worried that I would need to find more room...John
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Looks like there might be an Order Acknowledgement in the Christmas Stocking this year :)
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Yes, the size is nice and without the extra heat of a tube and power supply it leaves room for some experimentation with other plate materials such as CF or a tone wood.
-- Jim
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Cool! Can't wait. Sounds like this could be the event of 2014.
A couple questions:
1) Is the height the same as all BH kits? Could it be made slower or is the space needed?
2) Would this cause any electronic interference issues with, say, another BH amp if it were placed too close?
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Chassis is the same height as all others, because the DAC board hangs vertically in a shield box under the chassis.
As to interference, we get none in our setup. John took great pains to make a very quiet well shielded layout with very short signal paths.
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HOT DOG!
This is really getting me excited! and the idea of using the batteries is GENIUS! Simpler truely is better!
Now that I have been enjoying my Quickie for about a year Im wanting to change that over to a headphone amp and build a BeePree and one of these!
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A couple days ago I was sick and couldn't get a couple brain cells together to do any work (like laying out boards for the Bottlehead DAC) and decided to move the prototype into the main listening system. This wasn't easy, the dac board itself is tiny, but I need the linear power supply for the DAC and the squeezebox (running the DAC off the coax S/PDIF out from the SBT). Since I had some time I decided to set all this up, got it running, queued up some music and almost fell on the floor. Up to this point I had just been listening with headphones in the lab, WOW I was blown away!
With good speakers and amp the sense of space just overwhelmed me, this was well beyond anything I had EVER heard before. I just sat down and listened for hours. The sense of being "pulled in" to the music was astonishing.
I put about 500 tracks on the playlist, I just sat there enjoying the experience the rest of the evening, all night and the next morning. (I did get up to go to the bathroom, but that was it)
That was definitely the longest listening session I have ever had, and probably the most enjoyable. This DAC is really something special.
BTW it wasn't just because I was sick, that is all gone and I still get that reaction to listening to it. But now I have to go back to work so I don't have much time to listen anymore.
Thanks for being patient while we get this to you, it is definitely going to be worth it.
John S.
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John,
Very good news! At this point I have no more technical questions -- I don't feel any need to know any more technical details -- dac chip, output section, aasync, galvanic isolation, number of dac chips, etc. -- it's what comes out that matters and this sounds like something I'll just have to have in my system.
I was really impressed with the prototype that was at RMAF a few years back but it sounds like this is a whole different animal.
Sign me up!
Jim
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Yes this is a different animal. I have the previous DAC, the second prototype based on PCM1704s that were were demoing this the past year in the listening room. It's really nice and we got a lot of nice complements about it. But the new DAC has such a black background and such a lack of electronic artifacts compared to anything else we have used that it is the one being used all the time now.
John's software digital filter plays a very big part in this. We have a switch on the DAC that allows you to use the hardware filter that is internal to the DAC or John's filter. The hardware filter is very good, but we were joking that the switch is a feature you will only use once.
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Just get rid of the switch. Even better, leave the switch to select John's filter or no filter at all!
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I like the switch idea but don't take this the wrong way when i say please add an "off" position to it. Reason i say that is a lot of people will be put off by the very idea of a filter, and besides being able to toggle it on/off will help demonstrate the benefit. My vote is a 3 way toggle :D
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That's actually what the switch is for, the only way to turn off the filter built into the DAC chip is to feed it 352 or 384. By turning my filter off you can then use an external program to implement your own filter if you want to play around with designing your own. In order to do that you have to turn off my filter and send your 352 or 384 to the DAC chip which will then turn off ITS filter. The switch lets you do that.
If you are not doing that just leave my filter on.
There HAS to be a filter, if you just send a 44.1 or 96 or whatever, the DAC chip will use its own. The only way to turn it off is to upsample to 352 or 384.
BTW a reconstruction filter is not evil, it is a very good thing, it's just that all the DAC chip implementations have made compromises that adversely affect the sound quality. That is what my filter is all about, doing it right so you get the good things from a proper reconstruction filter with out the bad side effects of the DAC chip implementations.
The subject is fairly deep and complicated, it takes WAY more time than I have right now to give it justice in this post. I have written extensively about it on other forums, if you want to track those down you can get some of the details.
The over all summary is that not having an oversampling reconstruction filter is NOT the best sound. It may be better than some of the horrible sounding filters used in DAC chips, but a properly done oversampling reconstruction filter sounds way better than either no filter or the ones built into the DAC chips. The secret is to find the RIGHT filter and how to implement it without degrading the sound. I have been working on this for many years and what is in the BH DAC is the culmination of all that research and listening.
John S.
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Wow.. John , you sure have me sold with everyone of your posts... "does this make me TOO easy???" haha.. I know you have already mentioned the possibility of a DSD capability in the future.. and as I finally get around to reading all the "audio show" reports.., they keep saying the BIG thing this year is DSD.... All I want to say, is I very much hope that you can "for extra charge of course in the future" is make DSD or whatever available as an add on... However.. like ALL my previous EXPENSIVE digital components that are mint versions of extinct siliconasaurus rexs"... I am only saying, with infinite trust in Doc, PJ and You can try your best to make it somewhat upgradeable... I VERY much know, ALL of it is not in your hands , but the industry giant powers... My point is... I buy a $2500 dvd SOTA player.. 3 years later it is now basically a 500 dollar player.. Now my 45 pound copper chassis triple transformer beautiful gold beast is probably tough to give away.... times this by a few purchases.. and the digital world is quite painful to soul and pocket.... I MOST definitely will buy your DAC.. I have faith that upgrades will be available for as long as technologically possible.. THIS is why we should buy a Bottlehead DAC.. DOC and Company have already established the "off the charts" quality, price and just plain common sense STANDARD..... I really love how Bottlehead is a group of such QUALITY people... Thank you guys... SINCERELY........ disclaimer... NO , I do not get a free stay at PJs summer cabin, nor do I know Doc nor get any free stuff... nuff said...... However, gettin' hammered with PJ at his summer cabin shooting the breeze about audio?? yeah , that would be a cool day...:)
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Doc, what are the chances of a Xmas pre-order?
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John,
Really, really interesting as I've always been a big FAN of NOS dacs, no software SRC and the like, but I did get to hear the chordette dac with the fpla and proprietary processing software and it did some very nice stuff to redbook and what you're doing here seems very much along those lines but with your own algorithms, etc.
Yes, with every new post from you I'm more and more convinced that this dac will be sitting in my reference system.
Doc, what Sam said.
-- Jim
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It is exciting that the DAC may be getting closer to release! I would like to hear more about the analog output stage. It has been stated "no tubes". Is it op-amp or discrete? Basic topology?
I have heard several DAC's with the latest chips providing pretty amazing numbers. But I always go back to an early 2000's DAC with a tubed output stage. Why, when its numbers parts are antiquated? Because the analog output stage makes it play closer to music than the new super numbers machines.
I AM NOT saying that the output stage has to be tubes. I am saying that I assume that BH has spent an equal or greater amount of time on the critical output stage. I would like to hear some details about it.
Cheers,
Geary
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OK, I'm sold on the DAC and need to start saving my pennies, literally.
John,
I have a ST and wanted to know if you did any mods to the SPID/F out? The only thing I have done is build a PS based on your design using a Teddy Pardo reg and EDO.
Again can't wait.
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Doc, what are the chances of a Xmas pre-order?
This is really more in John's hands at this point.
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John is really busy with his day gig now, so it will take a little time to complete what needs to be done. He is laying out the final PC boards and then we will need to have samples made and test them. So we are talking early 2014.
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There is NO output stage! That is one of the reasons I like this DAC chip so much, it was designed to drive an output directly, no extra active stages and NO coupling caps! The output from the DAC chip goes through one resistor, the output of which has a cap to ground, this is the final analog filter for the DAC, that is IT!
I'm not exactly sure how they did it in this DAC chip, but it really does work and sounds amazing.
John S.
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Sounds Brilliant John :) With the ever changing DAC world... You HAVE to take your time to get it right.. we get it... And you are certainly doing it... kudos...
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And...... I do not know.. BUT... maybe.. for you tube output stage curious guys "me included"... MAYBE.... The Bottlehead team can/will release an independent/dedicated tube output stage product for the DAC, cd players, tuners, tape players etc..... to make and experiment with?? in our own systems........
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We have a nice tube stage available. It's called Quickie. ;^)>
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John, what's your source? I'm wondering if I'll need to upgrade my computer when I get the DAC. I have an old PC with a Juli@ card. No separate power supply. Not fanless.
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Great!! Doc... thank you !... My bad... thank you for the post, I was aware of people trying it as an experiment, but as a finished product? .. but I guess it is not necessary... ok , I get it.. ?)
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We have discussed the notion of a version with tube outputs and Nixie display. It would be very expensive.
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There is NO output stage! That is one of the reasons I like this DAC chip so much, it was designed to drive an output directly, no extra active stages and NO coupling caps! The output from the DAC chip goes through one resistor, the output of which has a cap to ground, this is the final analog filter for the DAC, that is IT.
Ahh so its an ODAC in a wooden box. ...joke :P
I certainly cant wait for you guys to show off the finished product, really curious to see the PCB's and what chips are in there. I already have an IOU from Santa in the bank..
Nixie tubes idea made my laugh, i have a bunch of Nixie tube alarm clocks in my ebay watch list that i cant get out of my mind. Expensive, but very cool looking..
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If I am mistaken... and I usually am here :)... I read that DOC said that tubes DIDNT make the DAC sound any better... So, this is of course a great thing because the end result will be simpler and CHEAPER... Who cannot love that... IF you want a tube output stage..?? I just learned, ADD a quickie...... Brilliant as hell because the quickie is what???? wait for it.... Battery powered as well... haha superb.....
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Someday in the future I'll build a Soul sister with MQ transformers at the input (B7 10k:10k Ni) and output (B7 8k:600 Co) and a pair of Co SR45s for which I have most parts. 'Cause contrary to my main system philosophy, for digital I think the mo' transformers the better to tame the digital beast.
Dear Xavier; You won't regret building the Soul Sister you have in mind. My PB-built version is wonderful whether driving the BH 2A3 amp and Blumensteins, or directly driving my HD 600's Cardas-cabled. I too have Mike's cobalt B7's but with IAG Sowter/Shallco transformer volume controls at the inputs. Vinyl is still my favorite source, and since PB built my custom Eros, I am re-acquainting myself with a large collection of mint discs.
Cheers, Hank in Eugene
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The DAC has three inputs. S/PDIF coax, S/PDIF optical and USB. They are all just as good as the other. (there might be very slight differences, but they will be small).
So anything that can output S/PDIF or any computer whose USB port can be used for UAC2 audio will work. What is going to sound BEST, I don't know at this point. I have put a TON of effort into making this as immune to outside influences as possible, so I expect that it will very good on just about anything without needing the extreme source tweaking that many other DACs require to achieve their best.
But nothing is perfect so you probably will be able to make it sound better with some sources than others, but at hi point I have no idea what that will be. The way I have done this is so much different than most other DACs that there is nothing else out there that can be used to make an educated guess at this.
Right now there are just two out there (mine and Docs), and I have not nearly enough time to actually try it with lots of different sources and computer combinations. I don't think Doc has done too much of this either. So it's really going to have to wait until lots of them get out into your hands and you guys can start doing some testing on this.
Currently I'm either using a Squeezebox Touch (S/PDIF coax or USB) or a wandboard running Community Squeeze software (squeezebox emulation) via USB. To me these sound identical.
This design is rather unusual in that it has both an extremely good S/PDIF input AND and extremely good USB input. In most DACs that have both types of inputs, one or the other will be significantly better sounding than the other.
John S.
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To Sam -- that means you can probably ddump the noisy PC and replace it with a single, fanless one board computer like an Alix or Cubox I, control it from an iPod/Pad/Phone and just run a usb cable to the bh dac and move thee pc to another room and use it as a fileserver. Or continue to use the PC until you want to use DSD when it becomes available.
No need, as John says, for a souped up mac mini or such to get stellar performance. Though I will hold on to mine until I can verify for myself that the alix or whatever can do as well as my over the top mac mini.
HTH,
Jim
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Jim,
I really like that idea! I'll shoot you an email off line with questions on how to accomplish it.
Regards,
Aaron
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John,
On the subject of USB interfaces and the article linked a few pages back i would interested to hear your opinion on USB isolators, specifically those built around the ADuM4160. I have heard people claim that they are problematic in that they increase jitter. Is there any truth to that?
Thanks,
Mark
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First off those isolators only work with full speed DACs, thus only work with UAC1, thus are only good up to 96 sample rate.
They definitely increase the jitter of the data signals. The technology used in ADUM can add a large amount of jitter. It's one of my least favorite isolation schemes. (I much prefer the GMR isolators from NVE, I use them in the BH DAC).
How that increase in data bus jitter winds it's way into the audio signal is complicated and will be different for different implementations.
The isolation CAN cut down on noise coming across the power and ground connection to the USB host, but it's difficult to say which will be worse, the decrease in noise or increase in jitter.
John S.
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Thanks John, informative as always, i need to re-evaluate my little isolator box solution now.
Also good to know the BH DAC will have some form of isolation built in, so no need to worry about such things in the future.
Cheers,
Mark
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Question,
Will using the USB input sync the clock from the computer to the DAC? I read somewhere that this is possible and results in better sound quality.
Not entirely sure how this works though.
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There are two different clock "topologies" for a DAC:
Source is master, DAC is slave
Source is slave, DAC is master
What matters is the jitter at the DAC chip (in the DAC). Having a fixed frequency clock in the DAC, right next to the DAC xhip is the best way to implement this. You can do this when the DAC is master, it has the "master clock". USB can do this in "asynchronous mode". The BH DAC uses asynchronous mode so it can do the DAC as master. In this mode the source (usually a computer) sends the data out, but the DAC can tell it to speed up or slow down so tha average data rate matches the clock in the DAC.
There is another USB mode called adaptive, in which DAC is the slave, but the BH DAC does not use this. SOME other DACs use this mode.
The S/PDIF inputs (coax and optical) just work with the source as master and the DAC as slave. Thus the DAC has to somehow synchronize its clock to the data rate from the source. This is traditionally done with a device called a PLL, which is built in to all the S/PDIF receiver chips. PLLs have much higher jitter than a good fixed frequency clock. The BH DAC does not do it this way. It cleans up the S/PDIF signal, and sends it into an FPGA (field programmable gate array) which does the S/PDIF decoding. But the special part is a digitally controlled ultra low jitter clock. This is almost as good as the best fixed frequency clocks. The FPGA tells this clock to speed up or slow down so it is synchronized to the average data rate of the source.
The result of this is that both S/PDIF and USB produce ultra low jitter to the DAC chip. This combination of ultra low jitter from BOTH S/PDIF and USB doesn't exist in any other DAC. On other DACs one or the other will be significantly worse than the other input.
John S.
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Cool
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Thanks for that detailed response John.
I am a computer guy but DACs go over my head a bit...must be all those video games.
I am looking forward to this though. I see in my head a small PC build into a Streacom case sitting next to a Bottlehead DAC and my Quickie(maybe BeePree in future?).
Only bad thing is that one thing that I MUST have is HT Bypass since I will be running my receiver through it as well to the amp. I will have to do this with a splitter I think though so that I dont waste any tube life for tv watching.
Music has to be tubes though!
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Only bad thing is that one thing that I MUST have is HT Bypass since I will be running my receiver through it as well to the amp. I will have to do this with a splitter I think though so that I dont waste any tube life for tv watching.
You could add a switch and extra jacks to the Quickie for this.
The BeePre's larger chassis and plentiful jack field make this a bit easier.
-PB
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That is something that I have considered. A way to bypass the preamp without it having to be on if possible.
We will see, I am waiting to see what happens with a few things before I go after this further.
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If the DAC is limited to a single pair of outputs will using an RCA splitter reduce the sound quality? I have both a SEX and Stereomour which I plan to use with with the DAC.
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Tom,
If I were you I'd use a second set of output rcas and a 4pdt switch to switch between them -- switches both hot and ground for both outputs -- you would'nt want a dirty ground from one device to spoil the other, if such a condition existed in your gear.
-- Jim
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If the DAC is limited to a single pair of outputs will using an RCA splitter reduce the sound quality? I have both a SEX and Stereomour which I plan to use with with the DAC.
I wouldn't sweat it, splitters should work great.
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If only somebody would design a switchbox kit to match our amps *hint hint* ;)
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If only somebody would design a switchbox kit to match our amps *hint hint* ;)
Couldnt the Submissive work like that?
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The Submissive allows for 3 inputs and one output. I have the same issue as I use a Crack and a Stereomour with the same DAC. I built a small switchbox using a project box with one input and two outputs and a 4PDT switch. I'm planning on building it into the BH Dac if there is enough underhood real estate. If I remember correctly there wasn't too much underneath to get in the way.
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If only somebody would design a switchbox kit to match our amps *hint hint* ;)
So you want us to design a kit that serves the same function as some RCA splitters?
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Any update or refined estimate(s) on the DAC kit price?
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Any update or refined estimate(s) on the DAC kit price?
We should have a price pretty soon. There are still a few items we need to do costing for.
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If only somebody would design a switchbox kit to match our amps *hint hint* ;)
So you want us to design a kit that serves the same function as some RCA splitters?
Better than that. Ideally i would want 2-3 inputs, and 2-3 outputs, and i would want the ground lines switched too so all the devices attached are disconnected from each other unless in use. Basically a knob to pick your source, and a knob to pick your destination, mounted in a chassis the size of the Fix would be ideal. The hardware from the quickie would be good enough for me, but leave enough room to upgrade to goldpoint switches if somebody wanted to.
Maybe i'm the only one with a need for such a thing, i seem to be constantly re patching RCA cables switching from speaker amp to headphone amp, DAC, to Set top TV box, to computer etc..
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You really want a patch bay.
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If only somebody would design a switchbox kit to match our amps *hint hint* ;)
So you want us to design a kit that serves the same function as some RCA splitters?
Better than that. Ideally i would want 2-3 inputs, and 2-3 outputs, and i would want the ground lines switched too so all the devices attached are disconnected from each other unless in use. Basically a knob to pick your source, and a knob to pick your destination, mounted in a chassis the size of the Fix would be ideal. The hardware from the quickie would be good enough for me, but leave enough room to upgrade to goldpoint switches if somebody wanted to.
Maybe i'm the only one with a need for such a thing, i seem to be constantly re patching RCA cables switching from speaker amp to headphone amp, DAC, to Set top TV box, to computer etc..
I'm with you on that one. It'd be great to have a kit like this that provides lots of input / output flexibility without any significant degradation of signal.
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Well a switchbox like that would be easy enough. Two 4P3T switches with knobs, a dozen RCA jacks, and some wire.
I'll even design the circuit and write the manual, for free. Switch positions 1-2-3-4-5-6 are hot1, hot2, hot3, ground1, ground2, ground3 for one channel. The other channel is the same using positions 7-8-9-10-11-12. Duplicate for the output switch. Connect the switches to each other, A-A, B-B, C-C, D-D. OK, my part's done. :^)
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Thanks Paul! Let's get back on the topic of hounding the BH team to get this product to market ;). Happy Holidays to the BH team and family!
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You know, with the amount of desire for this kit displayed here, I would suggest the following name:
"Lust".
Really looking for this for a few years.
Also, this is a great thread; I have learned a lot of stuff here, which makes me quite eager for this!
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This is all very interesting... I was tempted by the DDDAC 1794 with 4 decks but now I'm waiting for this DAC big time!
Nice work guys!
Do
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I have a Sonos Connect and I love the interface, but the sound is a little on the flat side. I am currently using it with an Emotiva DAC. I have read that the Sonos can be improved with modifications or an external reclocker, the Sonos suffers from poor jitter. Do you think the BH DAC will help with the Sonos or will modification or an external reclocker still be needed.
Thanks
Debra
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What interface are you using out of the Sonos? The BH DAC (whatever the name) has an exceptionally good S/PDIF input circuit that is very good at ignoring jitter coming over the wire (or fiber). So you will probably not need an external reclocker.
John S.
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Thanks for your reply John
I am using the Coax out to the dac
Debra
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OK I'll ask. Status update Doc?
Motorcycle Project? Ssssup?
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OK I'll ask. Status update Doc?
We are awaiting some boards that are in production.
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Would they be pre-production, or final production boards?
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They are production prototypes.
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Adding my hat to this ring. Was planning on literally putting an ODAC into a wooden box to go with the rig ;). This would be better...
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I can guarantee this will be in a different league to an ODAC, its a fantastic bit of kit for $100 but i have long since retired mine.
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I'm ready for the DAC as well. How complicated a build do you estimate it to be Doc?
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I hope they ordered enough circuit boards to handle the inrush of orders that this thread indicates.
I looked, I hadn't said it in this thread but did elsewhere, I'm in since I got the call back to work. I am expecting a top of the line price, would be really surprised if it were lower.
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Grainger, I've already had a custom base made for it! Hopefully they don't change the chassis plate dimensions ;)
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The sound you just heard is me laughing at your post.
It sounds like they are pretty well set on things now so I think you are safe.
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My 1984 CD player is starting to rattle louder! My fingers are itching to order a Bottlehead DAC!
I think I will try buying a Raspberry Pi to use with it - looks like they have a lot of possibilities like adding a remote, touch screen or differrent kinds of displays, etc.
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Subscribed!
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My 1984 CD player is starting to rattle louder! My fingers are itching to order a Bottlehead DAC!
I think I will try buying a Raspberry Pi to use with it - looks like they have a lot of possibilities like adding a remote, touch screen or differrent kinds of displays, etc.
I love the Raspberry Pi. I have 5 of them. But they are not the best choice for streaming HiRes files to a USB DAC. Have a look here for a better small computer option. http://www.bottlehead.com/smf/index.php/topic,5124.0.html (http://www.bottlehead.com/smf/index.php/topic,5124.0.html)
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There is another option for the Pi coming from HiFiBerry called the Digi which is a SPID/F that supports 24/192 out. I'm thinking this maybe a better option for using the Pi.
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There is another option for the Pi coming from HiFiBerry called the Digi which is a SPID/F that supports 24/192 out. I'm thinking this maybe a better option for using the Pi.
I actually ordered a Hifiberry DAC. I have a Raspberry Pi running Volumio. Definitely needs work, but the project is almost brand new, so that's OK. Pretty simple to get up and running and supports Airplay out of box.
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I have 10 days left to return my Emotiva Dac, but it could still be a long wait for Docs Dac! I don't think I can go back to my Fiio E07 while waiting.
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I have 10 days left to return my Emotiva Dac, but it could still be a long wait for Docs Dac! I don't think I can go back to my Fiio E07 while waiting.
Well you definately need something to listen to while you are waiting. I've been waiting a couple of years now. Doc B won't release anything until its just right, as it should be. I hate it when companies release a product when it isnt exactly "ready for prime time." Bottlehead hasnt let me down yet.
A friend of mine loaned me his Emotiva Dac when he bought his Schiit Bitfrost. I wasn't overly impressed with the Emotiva. Don't get me wrong it had some good qualities but it didn't have much to offer over and above an old VA Labs DAC I was using at the time. I wound up with the MyDAC as my interim DAC while waiting for the bottlehead DAC to be released. Some people dont like the plastic case on the MyDAC but it doesn't matter to me. Its what's inside that counts and it sounds real good in my system.
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Honestly, I hate to be the one to ask this as the answer surely relies on many decisions yet to be made but... Ballpark cost tier? Is this DAC catered to a Crack, S.E.X. or Mainline consumer?
EDIT: Sifted through the post and managed to find the answer I was looking for.
For those stumbling on this post recently without going through it thoroughly:
Due to the level of circuit sophistication the pre stuffed boards for this DAC are complex and quite expensive. I'm wrestling a bit with the pricing now that we have the project fairly well developed and I think the price will be under $1000. Probably not much under but we're squeezing it as hard as we can, short of hurting the sound.
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The price is still a moving target, partly because we are still refining the battery supply size and charging circuit components. But it is definitely more of a trying to keep it under $1000 endeavor than a $250 kit. The DAC board itself is very expensive to have manufactured.
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The price is still a moving target, partly because we are still refining the battery supply size and charging circuit components. But it is definitely more of a trying to keep it under $1000 endeavor than a $250 kit. The DAC board itself is very expensive to have manufactured.
Understood. Thank you for the prompt reply Doc.
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I want people to remember that this is not a "cheap DAC", this is the best I know how to make right now. There is no skimping on anything to a price point. Fortunately I know how to get exceptionally good sound without having to spend thousands of dollars on a single part!
For example this DAC has 6 ultra low noise regulators, they are not cheap (about $7 a piece), but far less than other "top of the line" DACs that use $75 regulators that don't perform any better. Or less expensive DACs that will use 2 $1.20 ones. It gives performance way better than the cheaper ones without the exorbitant prices of the other "statement" DACs.
Oh and Doc, I have a new filter that is significantly better than what you have now. I threw the one in your DAC together in an hour to have something you could hear. A couple weeks ago I spent some time with a friend and we tweaked the filter parameters to significantly improve the sound. By the time we were done it was the best he had ever heard. (and he has a special custom DAC that WAS state of the art)
John S.
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Woo hoo! Can't wait to hear something even better than what I have now!
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I already have a pretty good CD/SACD player, a Marantz SA-11S3. I'm thinking of running the analog outputs into the BeePre (just as I'm doing now), the digital output into the BH DAC and the output of that into a second input of the BeePre. The point of this is to improve standard CD playback. Questions:
1. Is there any reason why this wouldn't work?
2. Is it a correct assumption that the BH DAC will most likely sound better than the built-in DAC of the player? John has already indicated that the SPDIF input will sound equally as good as the USB input.
Thanks.
Gerry
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Good lord, I am really starting to itch. Please bring this to market soon! ;)
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Is it time for a Forum Pool?
Person closest to the actual price and open for orders date wins a Bottlehead Badge for only $6.00 +(S&H) :)
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$849
Available for pre-order May 25.
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$945, preorders 13 March
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April 1st ;) $750
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May 1, $999.
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I was going to say $250, pre order 1st April :P
$900, pre-order 3rd March
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$929, preorder April 15th.
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Hello everyone:
My first post here. My name is Alex Crespi, and I am the friend that John Swenson spoke of above. John and I have known each other for about 9 years. I first contacted him for an ahead-of-its-time digital project back in 2005--when Hovland Company, of which I was a co-founder, was still in operation. In fact the DAC which the Bottlehead prototype went up against on Janaury 4th is one of the NOS PCM1704K prototypes with discrete output stage that I inherited when Hovland closed its doors. It has had work done to it since: John put in a WaveIO async-USB>I2S board and better power supplies for the digital side. (If you want to know more about me or my system, I use the same Superdad handle over at ComputerAudiophile.com)
My custom room and system are pretty advanced, and I upsample Redbook to 176.4KHz with Audirvana Plus on a fine-tuned Mac mini booting a very slim OS off an SD card. I have spent a lot of time tweaking all the filter parameters of the iZotope SRC engine that A+ uses, so I have a good ear for what the parameters do. John's visit to my place this month (I'm about a 3 hour drive each way) was not his first, and we have spent time tuning a filter for a PCM5142 (the chip in the forthcoming BH DAC) before. It is amazing what a custom digital filter can do for an otherwise ordinary sounding DAC chip. The filters in most all other DACs are terribly compromised--especially if they are only the ones within the chip as the resources are terribly constrained. But the FPGA designed into this unit you have all been waiting for has plenty of room to load and run a really good filter.
At first we listened to the BH DAC fed by my Mac mini (both with iZotope upsampling and with that off to listen to the filter John already had in the BH FPGA). Power was provided by a prototype of a new PS that John and I will be producing in the next few months. The BH sounded pretty good.
John has techniques to output a list of filter coefficients from the excellent SoX sample rater converter--and to then load those into the FPGA. So what we did then was run SlimServer and SqueezePlayer on a Wandboard under COS (a customized Linux that the folks involved in the Community Squeeze Project have created--John is chief hardware designer for that non-profit project), and used the SoX plug-in to upsample to 352.8/384KHz (that rate turns off the PCM5142's own filter, and John turned off his FPGA filter). The filter already in the FPGA was based on some of the intermediate SoX parameters, but was not critically tuned to this DAC. The parameters are: cut-off, pre-ring/post-ring balance (that's the range of minimum-phase to linear-phase), filter length (that's number of virtual "taps"), steepness (for SoX this is controlled by frequency of cut-off and final cut, if I recall correctly).
Anyway, once we deciphered the numbers and ranges to enter the parameters (on an ugly command line for the SoX plug-in), we were able to spend about 90 minutes with the same four VERY revealing tracks (real instruments, real spaces, very challenging material top to bottom). We went one parameter at a time, bracketing wide, then narrow, until we were making the smallest possible adjustments. It is an iterative process (meaning we sometimes came back to one parameter after tuning another) and somewhat tedious, but John's ears, my system, and my 40 years as an audiophile/music lover (I started when I was 12) made it pretty easy.
In the end we were both grinning like fools. Really that DAC chip (and its built-in opamp output stage) had no right to sound as good as it did. Cymbals, piano, voices, strings, bass, drums--all top of the mark. I have heard a lot of DACs, and I am convinced this Bottlehead DAC will go toe-to-toe with some mega-buck units! Of course John quickly wrote down the numbers for the magic parameters we had settled upon and he's converting them for loading onto the FPGA.
So Doc, I think you'd best mark me down for a Bottlehead DAC too! (I don't mind coming after everyone else here who have waited so patiently.)
Anyway, I just though you might all enjoy a little insight into the final stage of what is going to be a GREAT and very musical DAC. It would be a steal even at twice the price of whatever Doc ends up asking for it. Based on what I heard with my own ears, I don't think ANYBODY will be disappointed.
Best regards,
ALEX
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WOW!
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Yeah. Word. Really amazing to get these insights into how much time, effort, patience, and dedication to quality has been put forth on this product development. Pretty cool stuff.
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Hi Alex,
Thanks so much for this added information and impressions.
One thing that has not been mentioned so far is how this dac does on tone -- in other words, where does it sit on the tone color scale. More to the Linn side or more to the audio note side?
Thanks,
Jim
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Question for John S:
How do you prototype these days?
When we were doing it (a long time ago) it was Augat wire wrap boards with DIP spacing for mostly 74XX logic parts . You could debug fairly effectively with a hand held Logic Probe.
Seems that there is a totally different methodology required with what's available today.
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Wire wrap and approaches like that are long gone. The only decent way is to have custom boards made. There are some places that do this fairly inexpensively. For simple stuff you can do your own, but for the boards I do now, it's cheaper to send them out.
The fun part is soldering. I have a hot air station, microscope and some other tools which allow me to hand solder many SMD parts, but there are some that are very difficult to do that way. The main Bottlehead board is a board that is almost impossible to solder by hand, so the only way to do it is have a professional assembly shop do it. There are lots of these around, but none of them are cheap. There are some that specialize in prototype work and I use one of those. So I send off board files, XY files and BOM files, Doc sends them a big chunk of money and a few weeks later we get finished boards.
I then test them out, find problems, and hack the boards up, cutting traces, adding tiny little wires etc, all dome under the microscope. I get it working, then go through the process again to hack up one for Doc and send it to him. Thus all the boards he has had so far have a certain amount of red wires and cut traces.
The ones in the fab right now have all the hacks from the last version incorporated into the board and hopefully will work out of the box.
John S.
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Thanks John,
I thought that was probably the case.
I guess the wire wrap gun goes to the re-cycler. :)
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Doc, I'd be interested in hearing your impression's on how the DAC sounds through the Orca speakers if you've had a chance to listen through them. My pair are just starting to really hit their stride and I'm looking to see if a new DAC will improve their sound.
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I have had the new DAC in the big system so far, so I haven't heard it with the Orcas. But I have a previous DAC prototype running in our home theater and after hooking it up I just couldn't go back to the analog output of the bluray player. So I can't say if you will like the new DAC, but I am confident that you could hear a difference compared to other sources.
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I really can't wait to see a BH DAC. I'm not sure how I'll be able to swing the price, but it's really exciting. Subscribed!
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We are awaiting some boards that are in production.
Bump for a progress report :)
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We are awaiting some boards that are in production.
Bump for a progress report :)
We are still waiting for the (hopefully) final prototype boards from the board house. I haven't heard anything about them for a while. I have a suspicion it is the oscillator, they have to be programmed for the specific frequency, that might be taking longer than anticipated. If so, all we can do is wait. I'll ping them tonight and see what is going on.
I have the adapter boards, they came in right on schedule.
John S.
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Has any guidance on enclosure size for the dac been given?
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Enclosure size is still a moving target until we determine the battery we want to use.The battery we have been using lasts about 4.5 hours. Unfortunately the last Seattle Head Fi meet was 5 hours and we didn't have the Play While Charging setting in that prototype. We ordered a larger battery just to see how much longer it would extend play time and once we test it we will decide whether we go with the bigger battery.
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I can already see my first mod, building a battery bank for a 12 hour run time :)
Probably a silly question, will there be any issues shipping the battery's overseas? Weight may be if they are SLA.
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I can already see my first mod, building a battery bank for a 12 hour run time :)
Probably a silly question, will there be any issues shipping the battery's overseas? Weight may be if they are SLA.
We will very likely have a position on the power switch that will allow enough charging current in to both run the DAC and keep the battery topped off, as well as a dedicated listening position where it is battery only.
Thankfully either battery that we are looking at falls into a class that flies under the radar in terms of shipping regulations. Though the batteries themselves do weigh a bit, that weight isn't drastically different than something like one of our smaller power transformers.
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Dan,
With my back I can't sit for 4.5 hours even in the La-Z-Boy. I wonder if many can.
If you have a charge while running position on the switch you are good to go for all the young guys.
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I talked to the board house today, the delay WAS getting the oscillators programmed, they have received them now and the boards are being assembled, they will ship next week!
I still have to write some FPGA code to get them up and running before I send to Doc. It shouldn't be much, this is mostly just bug fixes from the last one. The only real differences are the auxiliary port and the display, so I have to get those working.
John S.
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Could batteries be bought locally to save the hassle of shipping?
How about a two battery system? One plays while the other charges.
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Could batteries be bought locally to save the hassle of shipping?
How about a two battery system? One plays while the other charges.
I'm not sure what the hassle is. These are only 3-4 lbs.
We do not plan to leave sufficient room under the chassis for a second battery.
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So the optional Optima battery is a DIY add on?
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Cue thread on how 200 AA batteries is a better bang for your buck :)
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My experience is that most of these specialty SLA batteries have to be bought from specialty distributors anyway, so one way or another you're likely to have to pay for shipping.
-- Jim
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A lot of my Ham Radio buddies have converted from SLA to LIPO batteries. They are smaller and lighter in size for equal or larger capacity. Not sure about the cost but I believe the LIPO's cost a little more.
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I think i'm late to the party, is this the 'shut up and take my money' thread for the BH DAC? If so, i'll have to sign up, it'll be hard to resist swapping my John Westlake for a John Swenson ;)
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I 2nd that motion to rename this thread to
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv519%2Fqueenanthai%2FMade%2520Of%2520Fail%2Fshutupandtakemymoney_zps3bbbd52e.jpeg&hash=615e370bb273167488e81689695e60154b9e7529)
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I'm amused you are a fan of Futurama. Bender sits on top of my PC's case watching me post.
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I'm amused you are a fan of Futurama. Bender sits on top of my PC's case watching me post.
Bender = one of the greatest characters in all literature. :)
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Looks like PS Audio is going the fpga route in its newly announced dac. http://www.psaudio.com/wp-content/uploads/2014/02/PS-Audio-DirectStream.pdf What do you all make of described conversion of all signals, pcm included, into 1-bit dsd?
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Any new news on the DAC? :)
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John emailed me over the weekend that he had the production board up and running.
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That would not be a good choice. Really, you shouldn't be charging LiPos indoors at all. They really are dangerous.
The right chemistry for this application is Lithium Iron (LiFe). Unlike Lipos, they do not explode when charged at too high a voltage or current.
A lot of my Ham Radio buddies have converted from SLA to LIPO batteries. They are smaller and lighter in size for equal or larger capacity. Not sure about the cost but I believe the LIPO's cost a little more.
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subscribed!!
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Hi all... I've been away from the Bottlehead sight for a long while, and was wondering what the status, if any, about the Bottlehead DAC that's been in the works for a long time. I hope everyone has been doing well.
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should be DAC in the subject line
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Hi all... I've been away from the Bottlehead sight for a long while, and was wondering what the status, if any, about the Bottlehead DAC that's been in the works for a long time. I hope everyone has been doing well.
The message from Doc B on 3/10 is the latest update.
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Any updates?
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I'm waiting to hear from John myself.
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Here is the status: I had it playing music almost two weeks ago, but there were issues, such as not following sample rate changes properly and not starting when the FPGA filter was turned on. I have been working like crazy on these and have them all fixed, but somewhere along the line I broke something and have a strange corner case. If the DAC is on and you plug in an S/PDIF cable from a transport that is already sending out data anywhere from 2-5 minutes later the output gets highly distorted for about 5 seconds, then everything is fine from then on.
This is tough to debug since it happens randomly, but often enough to be not good. I want to get this fixed before I release it. I'm going to be working on this full time for the next couple days and hope to get it fixed. (and not break anything else!)
The final thing is to get the new filter encoded into the DAC, this takes a good part of a day, so I hope I can get the above problem fixed soon so I can get filter added and get this to Doc next week.
Even with the old filter it sounds fantastic, but with the new filter (running it on a computer to try it out) it's really amazing.
John S.
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The old saying is that it is hard to get Engineering to let go of their second best design to get it into production. The best design is always being developed.
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Keep up the good work, John!
And keep us updated, too :)
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It's all working now, I have the corner cases all working, it just works with everything I'm throwing at it now. I just finished getting the new filter installed. WOW, I thought the old one sounded good, this is over the top, I'm running out of words to describe it. I'm listening to a piece right now that I have heard thousands of times (it's one of my favorite test tracks) and I am hearing a bunch of instruments in the background that I never noticed before, it's amazing.
So all that is left is to hack up Doc's board. The assembler put the wrong part on the board and I have to hack in another chip to deal with this.
Then I'll send it out. So it might be tomorrow or at worst Wednesday for shipping to Doc.
Whew another song just started and I got goosebumps. The bass on this is amazing.
Now that everybody is drooling I'll sign off.
John S.
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>>> ring ring
> Hello, this is the bank manager speaking
>>> yeah you and I need to have a little talk about a DAC
> :o
>>> 8)
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Subscribed as well!
I have yet to finish my Crack/Speedball kit, but knowing this is on the horizon may be all the impetus I need :)
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Shut up and take my money already ugghh :):)
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Hey guys,
How's the beast coming? Is there a roadmap for orders in the pipeline? :D
Cheers /dom
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I just got the new board yesterday. PB breadboarded it and I ran it a bit late yesterday afternoon, feeding it via USB from my Mac Mini. Happily it finds every sample rate up to 384K and the 7 segment display is rock solid. Today I will test TOSLINK and coax digital inputs, which will be capable up to 96K for now with an upcoming firmware update that will make at least the coax input 192K capable.
John was not exaggerating about the improvement in his software filter. The dynamics are really something else with outstanding resolution and great tonal balance.
PB laid out a new panel for this setup yesterday. It is a little bigger than the last one and includes a bigger battery to help extend the operating time past the 4.5 hours we were getting with the last prototype. We hope to have a "near production" prototype together some time next week.
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So what size base are you using now, i assume you are sticking to the 6x10 or 8x10 format to keep it the same as the amps?
Also any chance of a pic since we lost the old ones?
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The current chassis plate that I designed is a 10" x 10". The last prototype was on an 8" x 8", but we needed a bit more space for the larger battery.
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Cheers to John, Paul B, and Doc for entering a mysterious and uncomfortable arena on our behalf! many of us hope for an All Bottlehead System, and the DAC is an important step along that path. Yay!
Hank in Eugene
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Just a brief update - TOSLINK has been tested today and passed with flying colors.
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Just a brief update - TOSLINK has been tested today and passed with flying colors.
How does it sound, by comparison?
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I found a nice NOS Shallco make before break six deck 27 pos switch to build a volume control for my HT so I'll definitely need three dacs. BTW I also have an electroswitch eleven position six decker so I could possibly build a coarse/fine volume control a-la-BH.
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Cheers to John, Paul B, and Doc for entering a mysterious and uncomfortable arena on our behalf! many of us hope for an All Bottlehead System, and the DAC is an important step along that path. Yay!
Hank in Eugene
Next step is the Bottlehead DAP - The Pocket Rocket!
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Just a brief update - TOSLINK has been tested today and passed with flying colors.
How does it sound, by comparison?
I was using two different sources to test how well switching between USB, TOSLINK and coax SPDIF worked. Switching was perfect. The USB source is a Mac Mini running Amarra and the other two sources were both coming out of a Panasonic Blu ray player playing a CD. So they sounded different, but I don't think it's the DAC inputs that made it sound different. I will be comparing USB and TOSLINK both coming from the Mini tomorrow, as that is a much more useful comparison. But for now it's time to rest my brain, been listening deep for several hours.
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I wonder if JohnS tested the USB input with a squeezebox touch and Triode's EDO mod, would be interesting
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There are too many factors upstream to be able to make a sweeping generalization about whether USB or TOSLINK or coax sounds better. USB and TOSLINK from one of our Minis playing off a hard drive via Amarra sounded great and slightly different. I would have a hard time putting one ahead of the other. TOSLINK from a blu ray player playing a CD sounded slightly worse than either. That correlates with my general findings of disc playback vs hard drive playback and also my findings of Amarra vs. CD player playback firmware, so it could have nothing to do with the inputs of the DAC. Coax from the blu ray player was worse than TOSLINK from the blu ray player. Who knows why, could be a cable issue, impedance mismatch or something else.
What I can say is that all three DAC inputs are very responsive to the sources, no problems handshaking. In fact the DAC helped us find that the TOSLINK output of one of our Minis was not working properly.
I can also say that the new digital filter seems to have cleaned up the sound from a temporal standpoint. Transients are cleaner and more dynamic and the decay of notes seems to follow the recording more closely, revealing more of the harmonic structure of instruments and really locking in the image.
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Awesome! Can't wait to hear more and eventually see the prototype.
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I'm super excited about the DAC and it sounds like its coming together very nicely.
Will it be possible to listen while the unit is charging? My Virtue amp is battery powered and I can't perceive any difference whether the trickle charger is connected or not.
I sure hope its not strictly off-grid as I'll likely want to listen for more than 5 hours at some point.
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...
Will it be possible to listen while the unit is charging? My Virtue amp is battery powered and I can't perceive any difference whether the trickle charger is connected or not.
...
Yes, this was previously discussed in this (lengthy!) thread.
There will be a switch to select between "charge+play", "full off", and "just battery."
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Ahhh. That's great news.
Thank you for confirming the behavior.
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"Full off" will probably end up being a charge-only setting that keeps the battery tended.
-PB
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We're also going to a bigger battery that should last longer.
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Is it time to take a head count for the beta run?
I'm in!
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Me too...John
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Do you have a ball park price at this stage id like start to budget for the dac ;)
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This is very ball park and I won't accept any complaints if it turns out to be different, but the price will probably be in the $1000-$1200 range. The DAC boards are very expensive to have manufactured.
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Do you expect it to be available to ship by the end of the summer?
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I would hope so.
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Cool. My birthday is at the end of August. And your DAC is what I hope to get :)
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John was not exaggerating about the improvement in his software filter. The dynamics are really something else with outstanding resolution and great tonal balance.
I can also say that the new digital filter seems to have cleaned up the sound from a temporal standpoint. Transients are cleaner and more dynamic and the decay of notes seems to follow the recording more closely, revealing more of the harmonic structure of instruments and really locking in the image.
Hi Gang:
In case you want to see the room where the tuning of the filter for the BH was done, here are a couple of pics. My room is entirely custom (a lot of crazy things were done in its construction that you can't see from the pics) and the speakers are rather special as well (no crossover on the custom dual-voicecoil woofer; first order roll-in for the dome midrange; tweeter comes in about 7K). Key to the tuning session were the very revealing tracks (of real instruments in real spaces with tremendous dynamics and lots of challenging sounds which resound to small temporal variations), and out methodically bracing the parameters.
Jonh is planning another vista soon for tests on another in-process project. I'm a 3-hour drive each way for him, but we always has a blast and finds our sessions very useful. My Hovland RADIA amp is very sideband, and he can hear things on them that don't show up through his headphone amp.
Feel free to ask any questions.
Best,
Alex Crespi
UpTone Audio LLC
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The painted wall is a nice optical illusion, i only noticed the curve looking at the carpet line ;)
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Just curious how things are progressing? Having read John's articles, I'm really excited for this kit whenever you all are ready to take orders!
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Prototype listening test today (I was there). There is a subtle difference between battery-only and battery-on-charge. One of those things that you can't listen for but are aware of if you distract your conscious mind. The DAC will be in use for the head-fi meet Saturday.
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Thanks for the update PJ. I'll look forward to reading any comments or impressions that are posted in the wake of the meet. Wish I could be there to meet you all and hear the latest revision in person. Maybe someday!
Is the subtle difference you perceived as between battery-only and charging within the scope of what you all had expected, or is this something that may result in further tweaks to the psu?
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The power supply does not need to be tweaked. At the flick of a switch you can set the DAC to be powered only by the battery. Yesterday's test was to find out if it makes an audible difference. The previous version of the charging circuit did not allow for charging while listening. That, combined with the smaller battery used in the previous prototype, led to about 6 hours of listening time. That would be fine for most listening sessions, but for long auditions we needed to have both longer battery life, and the ability to run it off the wall, if needed. With the larger battery, the DAC will run for almost a full day (at least 23 hours (no one could remember exactly when we turned it on...)) on the battery alone, or indefinitely, at slightly lower fidelity, with the charge and run setting. FWIW, I could not really hear a difference, but I am pretty ape-eared. Dan and the Pauls could definitely hear it.
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Awesome! Thanks for the further info. 23 hours on battery is amazing, and the option to listen while charging is highly valuable - especially if the audible impact is so subtle. Can't wait until an official order date is announced :D
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Is the subtle difference you perceived as between battery-only and charging within the scope of what you all had expected, or is this something that may result in further tweaks to the psu?
The battery supply was initially an experiment against the original bread-board DAC power supply. Generally speaking, I would estimate that this bread-board supply would add about $400 to the price of the DAC, and it didn't sound as good as the battery.
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The difference is subtle. Basically there is some HF stuff that is being removed by running off battery only. On battery only the treble is a bit more relaxed sounding, the presentation a tiny bit less bright. For me it helped to define the image a little bit better. It would probably be hard to discern much of this difference without the ability to switch the charger in and out on the fly.
We are closing in on starting a production run, just a few more details to work out.
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We are closing in on starting a production run, just a few more details to work out.
O boyoboy!
So excited. Gotta sell a bunch of CDs and DVDs on ebay to pay for this. Good timing, since the semester is about to end.
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We are closing in on starting a production run, just a few more details to work out.
O boyoboy!
So excited. Gotta sell a bunch of CDs and DVDs on ebay to pay for this. Good timing, since the semester is about to end.
That'll be a lot of CDs & DVDs or some very special CDs / DVDs!! :)
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We are closing in on starting a production run, just a few more details to work out.
O boyoboy!
So excited. Gotta sell a bunch of CDs and DVDs on ebay to pay for this. Good timing, since the semester is about to end.
That'll be a lot of CDs & DVDs or some very special CDs / DVDs!! :)
Several hundred, not all that special, though some are...
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We are closing in on starting a production run, just a few more details to work out.
Can't wait!!
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See the box with the 7 segment readout and the black chassis panel in the upper right corner? That's the functional prototype running one of our setups at the Head Fi meet we hosted yesterday. The display is telling you that it's playing a 96kHz file.
(https://www.head-fi.org/image/id/5971987/width/400/flags/LL) (https://www.head-fi.org/t/716282/lightbox/post/10493794/id/1093525)
Photo credit - Seamaster
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Looking good Doc. Is it safe to assume that you were using the USB input?
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Yes I use the USB output of the Mac Mini server in our system.
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Doc, can I ask how the new K812 stacks up against the K1000 and the HD800? I still really loved the tonal quality of the K1000 despite its age and thought it bested the HD800 in several areas but Ive not had a chance to hear if the K812 is a worthy successor.
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Suggest you check the meet impressions thread at Head Fi for more opinions, but I will say that they didn't float my boat on the mainline but sounded pretty nice on the S.E.X. amp. They are a pretty bright headphone, seems to me like they are a little hyped up to create a sense of presence and detail that may not be in the original recording you are listening to. The S.E.X. amp toned that down a bit and let them show that they have very good resolution.
My favorite is still the K1000s, and I still like the HD800s a lot. I also was impressed with the HE-6s and the Alpha Dogs. K812s were a bit behind any of those for me in that situation on that day. To each his own, beauty is in the eye of the beholder, opinions are like a******s, YMMV, TANSTAAFL, BYOB, ROTFLMAO, etc.
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Just a little update -
John, PB and I had a conference call tonight and we all verbally signed off on the current prototype. So our next step is to begin to arrange the acquisition and programming of the programmable components, one of which seems to take several weeks to deliver.
Hopefully by the end of the week we will have some hard numbers to work with and we can determine the price.
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Cool. 8)
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Cool indeed!
Bryan
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This thread is one year old and is the fourth longest thread.
There is a lot of interest in this product.
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Baited breath here!
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Does the DAC have a name yet?
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However long it may take, I'm sure it'll blow my mind once I can order one for myself hehe
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This is an exciting kit. Count me as one of the great unwashed masses standing patiently in line.
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However long it may take, I'm sure it'll blow my mind once I can order one for myself hehe
You did see this thread:
http://bottlehead.com/smf/index.php/topic,6257.0.html
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Is the Kickstart going ahead?
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Yes we will do a Kickstarter. It will take a little time to put it together.
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"It would probably be hard to discern much of this difference without the ability to switch the charger in and out on the fly."............... For us ultra lazy, a clapper circuit would be cool... on the more expensive side, a voice command module would be the bizzz..... :) "Battery, ON" and maybe "Kirk Out" for shut off....
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Thought control?
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With a clapper circuit installed, you would now be able to have Foreplay, Sex and The Clap.......... obvious name for the dac......
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I spit out my coffee! Thanks for that one!
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With a clapper circuit installed, you would now be able to have Foreplay, Sex and The Clap.......... obvious name for the dac......
Holy Clap... That is the post of the day :D :D
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I don't have the money yet, but I will save some and I am really looking forward to it.
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I'm almost there, been doing a purge of surplus stock, just sold a reconditioned turbo i had squirreled away so that took a good chunk out of it :D
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Will the dac be inverted phase or non-inverting? Will it be capable of switching polarity, and be able to do so from the remote?
Thanks
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and be able to do so from the remote?
Remote?
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That answers half of my question, thanks! :)
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Hi Doc,
Have you had time to plot out a timeline for the DAC Kickstarter?
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I'm starting to put a video together, which will take a little more time to complete. I'm sorry that I don't have an exact date for the kickstarter launch yet. Hopefully I will have a little better sense of the timing by some time next week.
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No worries Doc.Thanks for the update.
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I'm starting to put a video together, which will take a little more time to complete. I'm sorry that I don't have an exact date for the kickstarter launch yet. Hopefully I will have a little better sense of the timing by some time next week.
That is just time for Bottleheads to save their pennies and dollars.
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I forget if this was asked, and a search didn't come up with anything, but will the BH DAC require any drivers for USB? Or just native UAC2 support?
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Oh Doc, the excitement this DAC has caused among your brood. I know it'll be a giant killer.
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I forget if this was asked, and a search didn't come up with anything, but will the BH DAC require any drivers for USB? Or just native UAC2 support?
It is native UAC2, so no drivers for OSX or most linux, but does require a driver for Windows.
John S.
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It is native UAC2, so no drivers for OSX or most linux, but does require a driver for Windows.
John S.
Superior operating systems don't need drivers for such things ;)
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I ask because I'd like to know if it would work with this
http://wiki.jriver.com/index.php/Id
which runs Linux.
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I just set up a Intel NUC, there was a touchscreen on sale and it looked like it would do what I have dreamed my digital player would do. The Id linked, looks like its a NUC dn2820 which is pretty bare bones (which is fine if your just using it as a server, mine is d54250,which costs a lot more but will handle the GUI better). I am planning to use JRiver's GUI on the touchscreen. So far I'm impressed (still using the trial version of JRiver) soon I will move it to the main system, with a Ethernet connection to my router-nas (it is in the same area). Then I can also use a android device to control it from the couch. But the GUI is COOL on the touchscreen. I tested it today, NUC (wasapi USB)- V-link 192- PS audio DLIII- BeePre- Crack- HD600, sounded great! (I need the v-link because the USB on the DLII is old, IE. not class2, it converts it to S/pdif which the DLII uses fine). Now all I need is BH DAC!
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I ask because I'd like to know if it would work with this
http://wiki.jriver.com/index.php/Id
which runs Linux.
It should work fine with that.
John S.
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With a clapper circuit installed, you would now be able to have Foreplay, Sex and The Clap.......... obvious name for the dac......
Actually, not so 'bad'. Sex and the clap is one thing - let me tell you, when I was 22..no, I won't go there - but I'm thinking also of 'clap' as in 'applause', 'excellent', 'superior' - 'crackerjack' (which links, obviously, with guess what?) Anyway, Bottlehead Clap, I'm a certain buyer. When's it due. Or have I missed that post?
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I'd prefer Applause.
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It's been a while since the possible Kickstarter was announced. Will it still be happening?
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We have been slowed down in the process of building one more prototype to evaluate the ease of the build. The board is so expensive that we want to make sure a person with slim experience can put the kit together without inadvertently damaging it.
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I hadn't thought of that, but I guess that does pose a problem. If the risk is high enough what are the alternative options? Having buyers agree to pay for replacement of this part if such damage were to be their fault? Pre-testing the board somehow to assume that any non-working ones would have been damaged in buyer's attempted assembly? Doing the assembly of that part in-house, with the result being a price bump and longer shipping wait time?
Any of these would be acceptable to me.
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We are considering all of these alternatives and should have a resolution in the relatively near future.
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I would want PB to build mine into one of Clark's bases anyway, so I am probably in. Can't wait to see signs of the DAC waking up! Today's messages are sweet to hear.
Cheers, Hank
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Would it be prudent to install the PCB into its metal casing as not everybody will be familiar with how to handle sensitive electronics or general ESD precautions.
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It's not the details of how the board is protected in handling or what to tell the builder to do that is the issue. Everyone makes mistakes, it is an essential part of the learning process and we are pretty good at pointing out the potential problem areas in a build to keep those mistakes from being too costly. The big issue with this product is how loud someone would scream when they find out they wiped out a circuit board worth several hundred dollars by failing to follow instructions.
Tube stuff is incredibly forgiving, as we all see reading this forum. Surface mounted processors do not suffer fools lightly. If we can put the DAC out in finished form for a price close to the estimated kit price I think we may do that. Of course that would mean that any warranty would be void if opened up and fooled with. There's nothing inside to mod anyway, it's pretty much 90% prebuilt and mostly rather microscopic surface mount stuff.
At this point I'm feeling it may be best to spend our tech support efforts helping people to understand how to hook a DAC to a computer and get the best sound rather than saying "You did what? You're gonna need to replace the motherboard."
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Good idea... to just sell them built....
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As long as I have been slinging solder I would not touch a SMD.
Dan, I think you, all, have made a good decision.
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Well, it's good to hear this will still be happening. I've been talking it up so much around the house that my son now goes around talking about it. He's 6. He calls it the "king of the Bottleheads" or the "king of the DACs."
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Just wanted to report that I had a chance to spend a couple of hours listening to the most current pre-production version (V4) of the BH DAC board at my house this past Saturday when John Swenson came up to visit and test various things out in my system. Mostly we were experimenting with some DSD-only DAC prototypes fed by Audirvana Plus or HQ Player, but we also spent time enjoying the BH DAC (powered by my UpTone JS-2 choke-filtered LPS). It functioned perfectly, and we listened to a wider array of tracks than we had time during the prior session (the one where we tuned the SRC filters for loading into the FPGA).
It sounded glorious! Much better than I remembered. My system has improved some since last time (Swenson designed Linear Fan Controller in my new 2012 i7 Mac mini; Supra USB cable driving the BH, etc.), so that might account for it. Every genre: jazz, classical, folk, rock--subtle or bombastic--rendered in perfect proportion, with detail, tactile musicality, and emotion.
When Doc and company get this baby into production you will be hard pressed to match this sound for anywhere near the price.
Cheers,
Alex Crespi
UpTone Audio LLC
Mariposa, California
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We have our latest board up and running too. I have been using it to work on some recordings I made that I have transferred from tape to high res, and it's sounding very good. We are thinking that we can sell the DAC ready to run with wall wart power for a price pretty close to the original kit price goal. We are also thinking that we will offer an outboard battery-with-self-contained-charger power supply upgrade as a separate kit. This should reduce any risk of the DAC owner blowing up a very expensive mother board due to miswiring or other construction error yet it still gives everyone a chance to DIY a kit that is related to the DAC.
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Dan, thanks for the update. I'm back inboard with this project!
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Excellent solution.
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Will the DAC still be a kickstarter project?
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Any updates sir?
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PB has been working on the new cabinet layout. We plan to test a couple of different cabs and the second one is not here yet.
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Second cabinet arrived this week. PB is working up the design for the end panels. I have begun to lay plans to take the DAC to 1340 Mission once it is complete. There we can compare with some Pacific Microsonics Model 2s and some other studio quality D/As.
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End panels? Is PB doing some alloy panel origami on this one?
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The cabinet is a rectangular tube with panels on the front and back. Kinda conventional compared to what we usually do, but it will help to keep the cost of this finished product close to what a kit version would be priced at.
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The wood base / chassis plate layout never really worked for me with the DAC so i welcome the change. Looking forward to it..