Bottlehead Forum
General Category => Technical topics => Topic started by: Lar on February 18, 2012, 08:37:06 PM
-
Anyone have any info or links for DIY power supply for Touch? 5v 3A. Any info much appreiciated.
-
Anyone have any info or links for DIY power supply for Touch? 5v 3A. Any info much appreiciated.
If you haven't already done some searching over at the Slim Devices forum, I suggest you spend some time there. The older SB3 really benefited from changing the power supply but opinions are very divided over how much (if anything) is gained with the Touch. The Touch has an internal switching supply in addition to the wall wart and many believe that little is accomplished aside from perhaps limiting noise feeding back into your mains. I put a linear on my Touch and perceived no difference in sound at all.
Anyway, it would be best to head over there and do a search in the Touch forum for power supplies, linear power supplies, etc. to see all sides of the issue and make up your own mind. IIRC, John Swenson over there has posted plans/schematics for what you might be looking for. Here's the schematic. (http://johnswenson1.home.comcast.net/~johnswenson1/stereo/SB_5V.GIF)
http://forums.slimdevices.com/showthread.php?t=82648&highlight=power+supply+schematic
http://forums.slimdevices.com/showthread.php?t=79977&highlight=power+supply+schematic
-
I am using an older (refurbished) Red Wine Audio that uses SLA batteries with a regulator to power an SB Touch. Happy with the blacker background and effortless punchy output via the 1/8" headphone plug and the RCA's.
-
I use a modified Jerome linear power supply for my SB Touch. I understand they are now discontinued. Wayne over at Bolder Cable Co. has a lot of great ideas/products for the Touch and other such products: http://www.boldercables.com/servlet/StoreFront (http://www.boldercables.com/servlet/StoreFront) Take a glance at his storefront or check him out on AudioCircle for some ideas, perhaps.
John
-
If you are using the DAC in the Touch IMO you would be best served to get a better DAC and use the Touch as the server/transport. Modding the power supply is not going to get much bang for the buck. For the jollies I would build a NMH battery pack and see if it makes a difference. Not sure how sensitive the Touch is to voltage variation though.
-
These issues are highly debated (just see the attempts to discuss the Mac Mini) so I don't want to get into a back and forth. Of course, here I go with my post, anyway, right?
However, I have found based on my personal experience that the stock SB Touch is less than what I would listen to with even a modest off-board DAC. However, once I had my Touch modified by Wayne (I did the "digital" mod and the power supply mod, including Bybee Music Rail), the change was dramatic. It would be very easy to A/B if someone had a stock SB Touch...I have no doubt that every single person would prefer the modified Touch and not by a small margin.
There are different levels of modification as well as different types of modifications possible. These include the Touch itself (modifying the digital side, the analog side, and the internal power supply) as well as the external power supply (linear, linear plus better filters, linear plus better filters and Bybee Music Rail). There is even a simple analog mod for under a hundred bucks that, when combined with a linear power supply, would be a noticeable change.
I was impress by the impact of well designed mods to the Touch. YMMV
John
-
Thanks for all the feed back, i think i will do more reading. its all about choices and $.
-
These issues are highly debated (just see the attempts to discuss the Mac Mini) so I don't want to get into a back and forth. Of course, here I go with my post, anyway, right?
However, I have found based on my personal experience that the stock SB Touch is less than what I would listen to with even a modest off-board DAC. However, once I had my Touch modified by Wayne (I did the "digital" mod and the power supply mod, including Bybee Music Rail), the change was dramatic. It would be very easy to A/B if someone had a stock SB Touch...I have no doubt that every single person would prefer the modified Touch and not by a small margin.
There are different levels of modification as well as different types of modifications possible. These include the Touch itself (modifying the digital side, the analog side, and the internal power supply) as well as the external power supply (linear, linear plus better filters, linear plus better filters and Bybee Music Rail). There is even a simple analog mod for under a hundred bucks that, when combined with a linear power supply, would be a noticeable change.
I was impress by the impact of well designed mods to the Touch. YMMV
John
wow! Thanks for the insight John - I think many in the audiophile community were under the impression (ex. Stereophile) that the bit perfect delivery from the Touch was, well, perfect! I was a bit skeptical and have duly added your impressions to the data bank.
-
If you think about it the biggest improvements come from power supply upgrades. Even the upgrades to the BH products are for the most part power supply upgrades. Granted there are things like cap and resister upgrades to the signal path, but in my experience the upgrading the PS makes the biggest difference.
-
I think Eric's suggestion of cobbling up a battery supply, is a good one. Give you a quick read on whether its worth pursuing...John
-
wow! Thanks for the insight John - I think many in the audiophile community were under the impression (ex. Stereophile) that the bit perfect delivery from the Touch was, well, perfect! I was a bit skeptical and have duly added your impressions to the data bank.
Eric,
I'm not trying to pass myself off as an expert...I certainly am not. However, I decided to try the Touch mods after (1) owning a Touch for over a year and (2) basing my mod path on the recommendations of others whom I have learned to respect based on shared experiences or overall philosophy. I'm so much happier with my Touch today than I was before. Here is a quote from Klaus with Soundcheck:
The myth that "0s are 0s and 1s are 1s -- it's all digital don't care about" is simply said wrong and misleading.
It's not about just digital 1s or 0s actually. The data receiver must be able to read a certain analog voltage and need to declare it a 1 or 0. Since timing and shape of that bit and its distortion are continuously changing and usually far far away from being ideal, the receiver will see all but a clean rectangular evenly separated noise-free signal. In the majority of cases the situation is that bad that a receiver is not able to recover respectively refresh that incoming bitstream properly.
If people are talking about bit-perfection or bit-transparency, it won't tell you anything about the actual sound quality. Bit perfection just says that the value of a bit (or sample) arrived as it was sent - as a 1 or 0 - but it doesn't say at what time resp. in what condition it arrived (or even it's reflection arrived) and if and how the receiving end is able to cope with that condition. And that's a key issue. The vast majority of DACs out there are just not able to properly cope with quality issues on the incoming bit stream respectively connection.
The link to the above quote: http://soundcheck-audio.blogspot.com/2011/11/touch-toolbox-30.html (http://soundcheck-audio.blogspot.com/2011/11/touch-toolbox-30.html)
Kind of an interesting twist on the "bits are bits" argument. And that doesn't even get started with the power supply side of the story...which is really where things get exciting!
I hope you enjoy this dialog....
John
-
Yes i`m interested in seeing where i can take my Touch. At present it sounds pretty darn fine, but i know it could be better. Power supply is really of interest to me. The journey continues.
-
John Swenson, who is designing the digital portion of the Bottlehead DAC, has quite a bit of experience with the Squeezebox and Touch. You might do a google search to see what he may have written on the subject. Like us, John believes very strongly in the value of excellent power supplies.
-
Below is a quote from one of John Swenson's posts on the Slim Devices Forum, directly addressing linear power supplies and the Touch (color emphasis is mine). I agree that quality power should be the goal in good audio. The question here is whether or not substituting a different DIY or third party power supply on the Touch improves the sound that the user perceives. That perception can come from many sources and perhaps the reason some tell of improved sound is because of the noise that is not sent back down the AC line. (I'm not going to start in with cognitive bias - that's a whole other thread fraught with minefields...)
My conclusions are that a large percentage of improvements with PS design for the Touch are related to high frequency noise sent BACK into the mains and picked up by other components. power sent into the Touch itself has little impact on what goes on inside the Touch (not zero, but quite small). The differences in mains injected noise is vastly greater than any changes in the power actually delivered to the components inside the Touch.
Given this the focus of PS design should be on decreasing what gets sent back down the AC line, not making the absolute lowest noise, lowest impedance feed to the Touch. Many of the attempts at getting the "best" power to the Touch increase the noise sent down the line.
For a linear supply there are primarily three things that contribute to noise sent back down the line: reverse recovery noise when the diodes switch, transformer ringing and current spikes when the diodes conduct.
I perceived no change in sound when I substituted a linear supply. Perhaps it was the supply I chose. Perhaps it was my home's AC service. Perhaps I didn't expect to hear any change to begin with. I'd encourage Lars to look at John's design and read the entire Linear Power Supplies (http://forums.slimdevices.com/showthread.php?t=82648) thread on the forum. Strong opinions all around but generally civil and informative.
-
This should be close to what you are looking for:
http://glass-ware.stores.yahoo.net/lvregulatorkit.html (http://glass-ware.stores.yahoo.net/lvregulatorkit.html)
-
This should be close to what you are looking for:
http://glass-ware.stores.yahoo.net/lvregulatorkit.html (http://glass-ware.stores.yahoo.net/lvregulatorkit.html)
This looks interesting, thanks, and it won`t break the bank!
-
Below is a quote from one of John Swenson's posts on the Slim Devices Forum, directly addressing linear power supplies and the Touch (color emphasis is mine). I agree that quality power should be the goal in good audio. The question here is whether or not substituting a different DIY or third party power supply on the Touch improves the sound that the user perceives. That perception can come from many sources and perhaps the reason some tell of improved sound is because of the noise that is not sent back down the AC line. (I'm not going to start in with cognitive bias - that's a whole other thread fraught with minefields...)
My conclusions are that a large percentage of improvements with PS design for the Touch are related to high frequency noise sent BACK into the mains and picked up by other components. power sent into the Touch itself has little impact on what goes on inside the Touch (not zero, but quite small). The differences in mains injected noise is vastly greater than any changes in the power actually delivered to the components inside the Touch.
Given this the focus of PS design should be on decreasing what gets sent back down the AC line, not making the absolute lowest noise, lowest impedance feed to the Touch. Many of the attempts at getting the "best" power to the Touch increase the noise sent down the line.
For a linear supply there are primarily three things that contribute to noise sent back down the line: reverse recovery noise when the diodes switch, transformer ringing and current spikes when the diodes conduct.
I perceived no change in sound when I substituted a linear supply. Perhaps it was the supply I chose. Perhaps is was my home's AC service. Perhaps I didn't expect to hear any change to begin with. I'd encourage Lars to look at John's design and read the entire Linear Power Supplies (http://forums.slimdevices.com/showthread.php?t=82648) thread on the forum. Strong opinions all around but generally civil and informative.
This is very interesting. I wonder if the improvements I've heard (and believe anyone would hear) are more the result of the reworking of the internal power supply as the weakest link in the chain? Here is what I had Wayne do to the Touch:
The mods start out with improving power supply delivery and decoupling to the critical digital sections. We then install a custom voltage regulator circuit just for the digital output section and clocks.
Perhaps if you haven't done this, the rest doesn't matter. That would then make the external PS much more critical as the next weak link and that is why my results were different.
John
-
Interesting about the noise getting back into the mains from a device. I noticed my SMPS for my t-amp possibly contributing noise - I think my battery powered Quickie was picking it up! Even though the power supply was many feet from the Quickie. When I switched out to battery the noise went away. I also spent a chunk of change on my JPS Labs digital power cord based on some of that logic. I use it on my Transporter. I think it did make a "significant" difference (clarity, resolution) although it was not my highest value tweak.
-
This should be close to what you are looking for:
http://glass-ware.stores.yahoo.net/lvregulatorkit.html (http://glass-ware.stores.yahoo.net/lvregulatorkit.html)
I just purchased one of these myself, along with a Hammond transformer and a small aluminum box to make a power supply for a Wadia 171 iTransport. Granted I don't have tons of knowledge on the subject of power supplies, so I'll be doing some reading before assembly. It's nice to know why things work the way they do ;)
-
This looks like a nice power supply option (SR1-MR ) for the SB.
http://www.paulhynesdesign.com/page7.html (http://www.paulhynesdesign.com/page7.html)
-
I own one of these for my SB Touch .... works very well.
http://www.welbornelabs.com/squeeze.htm (http://www.welbornelabs.com/squeeze.htm)
-
I wish every linear power supply was built like this. I don't know what he does for a living, but Mr. J. Swenson knows power supplies.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fjohnswenson1.home.comcast.net%2Fstereo%2FSB_5V.GIF&hash=bb8fc0a00b6ebf4f6a17b654e0d3f0a7234b444b)
This power supply models quiet and it tests quiet when built. Thanks for pointing it out. I might go with a different transformer, possibly a Hammond 229Cxx where xx is voltage, but that has to do as much with availability as it does performance. It is fairly easy to substitute other regulators for different output voltages. Very, very nice indeed.
-
Sorry, no wonder, I now read the part where John Swenson explains his job responsibilities in the same thread: this is a power supply designed by someone who designs way more complicated power supplies for a living. You can make this a commerical design and never look back.
Not cheap, by the way, a nice transformer and the choke alone will set you back about $60 at single unit prices, but nothing that good is ever cheap. The size of C2 is a huge factor in the design and how about those 20A Schottky diodes in a 1A power supply. Those don't add much to the price either. Did you notice the three different kinds of Panasonic caps: FC, TSHA, FM, FM? This is almost too good to be true.
-
I dont know alot about the Squeezebox or this stuff in general, but wouldnt a kit like this work for it? ... http://www.amb.org/audio/sigma11/
I have a digital player that runs off a battery or a wall wart. The sound was noticeably better off the battery than compared to the wall wart although describing it is not my forte.
I built the sigma 11 using decent parts and was pleased to find that when powered by my completed project, I heard no difference between the battery and the power supply.
It wasnt a very expensive enterprise so was well worth it for the extended playing time. Again, I dont know if it is appropriate for the Squeezebox.
-
I wish every linear power supply was built like this. I don't know what he does for a living, but Mr. J. Swenson knows power supplies.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fjohnswenson1.home.comcast.net%2Fstereo%2FSB_5V.GIF&hash=bb8fc0a00b6ebf4f6a17b654e0d3f0a7234b444b)
This power supply models quiet and it tests quiet when built. Thanks for pointing it out. I might go with a different transformer, possibly a Hammond 229Cxx where xx is voltage, but that has to do as much with availability as it does performance. It is fairly easy to substitute other regulators for different output voltages. Very, very nice indeed.
If it was translated into a manual that looks like Doc`s i would build it, otherwise i`m lost. ):
-
Thanks for posting this schematic. I'm saving it for projects that might need it.
The filter on the secondary side of the transformer, the RC, is a very nice touch. I think it functions like the old RRSF of Seduction and FP 2 circuits. It was a FP 2 upgrade that became a stock part of the Seduction's circuit. It absorbs the noise from reverse leakage of each diode.
Changing the transformer voltage and the regulator voltage would make this appropriate for all sorts of things (keeping in mind the cap voltage rating might need to change if you go above say 25V input). I'm wondering if the choke needs to change for anything but the circuit current rating.
-
Lar,
Sorry I did not see this thread earlier, there is a DIY ps for the Squeezebox at www.teddypardo.com. I have not built or used it but I do know a few people that like it on their system.
Cheers,
Shawn
-
Lar,
Sorry I did not see this thread earlier, there is a DIY ps for the Squeezebox at www.teddypardo.com. I have not built or used it but I do know a few people that like it on their system.
Cheers,
Shawn
Thanks for the link, but i already have one just about done. Its the LV - Regulator, i figured it has my initials i should build it.
-
Great job Lar! I bought my SBT with a CIaudio ps as a package deal. I just picked up a nice 128GB ssd that I converted to USB, I plan on using either a Sheevaplug or a Goflex net to make the SBT a stand alone server with no computer required.
Cheers,
Shawn
-
Great job Lar! I bought my SBT with a CIaudio ps as a package deal. I just picked up a nice 128GB ssd that I converted to USB, I plan on using either a Sheevaplug or a Goflex net to make the SBT a stand alone server with no computer required.
Cheers,
Shawn
Interesting idea with the Sheevaplug or Goflex, is that 128GB drive big enough? I find with my High Res music files take up lots of real estate.
-
Interesting idea with the Sheevaplug or Goflex, is that 128GB drive big enough? I find with my High Res music files take up lots of real estate.
Yeah, unfortunately it's all I can afford at this time, I went with the Goflex so I can dock a 1TB esata drive and store files on it as well. Squeezeplug will work with esata but I will most likely rotate files on and off the ssd for playback.
Cheers,
Shawn
-
Finished product, Grainger, i used some heat shrink at the tranny points close to the box to keep the sparks down.
-
Lar, how does it sound installed, any improvement?
Cheers,
Shawn
-
Lar, that looks very clean...nice work! Everything else is stock, right? I, too, am interested if you are hearing any sound quality changes. John
-
I have not had much time to do any critical listening, but i will, i have noticed a quieter back ground , but that i`m sure would be system dependent. And yes the Squeezebox is stock.
-
Hey Lee,
How you doin? Thanks for the Glassware site. Have you experimented with any of their stuff ? I've toyed with the idea of having a variable voltage power supply, be nice for test and experimenting.
Regards,
John
-
I have enjoyed the results of the LV - Regulator power supply i decided to make it a big brother and built this John Swenson designed power supply, so far sounding very good.
-
That is great Lar, you get alot of satisfaction out of building your own gear! Where did you get the plans for Johns design? I changed my set up for the SBT, I bought a vortexbox appliance, which I converted to fanless, added 3 more gb of ram, replaced thie internal hd with a 60gb ssd, and set up an external 2 drive raid for the file storage ( 2 480 gb solid state hds), when I build a mac mini based server I'll use the raid because it can also connect to esata. Again, great job on the ps.
Cheers,
Shawn
-
Yes it is a lot of fun building this stuff, and thanks. Page 2 of this thread, post 127 from Grufti has the schematic of John`s design. How do you like the vortexbox?
-
So far I am liking the vortexbox, if you have alot of cds or dvds that need to be ripped it is perfect. I was originally going to build my own mini pc and install vortexbox but after buying memory the HDs and performing an ISO install of the vortexbox os (fedora linux based), I decided to buy the appliance and modify it for my own uses. The first night I had it I ripped 65 CDs to flac without any issue. Most took 3-5 minutes, but there were a couple that were damaged enough that the cd paranoia error correction took about 20 min. to complete. I don't like it's tagging structure for classical so I am ripping all of those using Max, XLD under OSX and dbpoweramp under windows. The appliance uses very little power, so leaving it on 24/7 is not a problem and it came with LMS already installed.
Cheers,
Shawn
-
Anybody out there feel like doing me a huge favor and translating the schematic for the swenson power supply into words for me?
I just bought a sb touch and will send it to Bolder Cable for analog mods, will then tweak with the soundcheck 3.0 tookit, but also want to build a killer psu for it.
Does it look easy to slightly change the output voltage of this design -- say from 5.0 to 5.7 or 5.8? I have a bybee music rail I may want to try in it later and that eats up about .7-.8v itself.
Thanks,
Jim
-
Jim,
If you mean the schematic posted on the previous page by Lar, I can do that. The regulation comes from an LT1084, a fixed 5V three pin regulator. A variable regulator can be substituted and you can dial in the voltage you want.
-
Thanks, Grainger, and yes, that's the one. Please, if I may ask, include all parts designations such as type, size, series, etc. -- according to Hans, the types of caps are important too, as is I suppose just about everything else.
Thanks much,
Jim
-
I will give it a go.
Transformer, Triad VPS10-2500. Across the Secondary, is a stubber consisting of a .022uf cap in series with a 330 ohm resistor.
To a full wave bridge, STM STPS20120D is the listed diode.
Next is a CLC filter. All caps are Panasonic, 35V.
120uf, FC
10mh, Hammond 159 ZJ
10000uf, TSHA.
This feeds a 3 pin LT1084 regulator. The input has a 470uf, FM, essentially in parallel with the 10000uf cap, just closer. P3 (input) to P1 (ground).
Then another 470Uf , FM. From the output (P2) to ground, (P1)
-
John and Grainger,
Thank you both very much! You guys rock! Seems simple enough but the devil is in the details. Just wondering why such a monster of a bridge -- maybe diodes are less noisy when used at far lower than their rated current?
I may even have a nice split-bobbin transformer I can sub. I may even have 90% of these parts on-hand.
Anybody know the O.D. and I.D. for the DC barrell connector for the Touch?
Thanks much -- love this forum!
-- Jim
-
Nice work on that 5V PS Lar, looks very nice :)
-
... Just wondering why such a monster of a bridge -- maybe diodes are less noisy when used at far lower than their rated current?
...
-- Jim
Like the idling motor in a car: very little noise. Wait until you hold the choke in your hand. That qualifies as monster also.
-
John and Grainger,
Thank you both very much! You guys rock! Seems simple enough but the devil is in the details. Just wondering why such a monster of a bridge -- maybe diodes are less noisy when used at far lower than their rated current?
I may even have a nice split-bobbin transformer I can sub. I may even have 90% of these parts on-hand.
Anybody know the O.D. and I.D. for the DC barrell connector for the Touch?
Thanks much -- love this forum!
-- Jim
O.D. - 5.5 mm I.D. 2.5 Long - 11.0mm :) plug size but that should help.
http://ca.mouser.com/ProductDetail/Switchcraft/760/?qs=sGAEpiMZZMu2f9RNbWupYubSmEXlq6O0Wd4VeTPXD68%3d
-
Lar,
Thanks very much -- doubly so for the mouser part number.
Got the new Touch yesterday and I'm pretty impressed with the quality of the piece -- as compared to the original SB, sb2 and sb3 -- all of which I've had in the past.
Did you take the electrolytic coupling caps out of your analog outs or are you just using it as a transport?
-- Jim
-
Lar,
Thanks very much -- doubly so for the mouser part number.
Got the new Touch yesterday and I'm pretty impressed with the quality of the piece -- as compared to the original SB, sb2 and sb3 -- all of which I've had in the past.
Did you take the electrolytic coupling caps out of your analog outs or are you just using it as a transport?
-- Jim
I`m only using the digital out, its all stock, as well as the new firmware for 24/192 output. I have an Emotiva Dac connected to it, impressive sound out of a little box. http://forums.slimdevices.com/showthread.php?94512-Announce-Enhanced-Digital-Output-app-USB-Dac-and-192k-Digital-Ouput
-
Nice work on that 5V PS Lar, looks very nice :)
Thanks, which box are you referring to? I built two?
-
Hey Lar, so you are running USB out to the Emotiva DAC. I've heard good things about that relatively inexpensive DAC. So is it asynchronous? I am just using optical out on mine, of course tht is limited to 24/96. I guess I will have to install the firmware upgrade and give it a try.
Cheers,
Shawn
-
Hey Shawn, I`m using the coaxial out, the Dac is limited to 16/48 in USB, unless you use USB>SP/DIF converter so i just went coaxial. At 199.00 its a steal, but I expect they are coming out with a new one in the near future to address the USB shortfall.