Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: networkn on June 08, 2014, 01:55:49 AM
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Hi I have my crack amp resurrected after a LONG break away, and keen to resolve a problem which I couldn't really find the root cause of last time.
Essentially the issue is that my voltages and everything check out, the sound is coming through loud and clear, and seems the amplification is working ok, but there is a weird interference issue not quite like static, which I am not sure the source of.
It changes ears depending on how far in or out of the jack it is, and almost sounds like high frequency (as in how fast it occurs not sound frequency) clicking with a high pitched sound coming through as well. I can detect it with anything plugged into the headphone jack and source doesn't appear to be the problem.
Is it quite likely the headphone jack?
The sound is recorded (barely) on my phone and is available to hear here, sort of. It's much much clearer than this on my ear!
https://www.dropbox.com/s/a5hdblk1pmsm1zx/Voice%20001.m4a
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Turn off your cellphone and wifi router.
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Turn off your cellphone and wifi router.
Didn't help. What's next? When I wrote interference, perhaps I use the wrong term.
What component of the Amp could even be running at the same frequency of the cellphone or wifi ?
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Volume doesn't have any affect on the sound issues I am experiencing.
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Is it quite likely the headphone jack?
No, it most certainly isn't the headphone jack.
This could be a funky solder joint on one of the UF-4007 diodes, or elsewhere in the power supply. With your headphones plugged in, do you get this noise in both channels or just on one side?
Also, if you used plumbers' solder or plumbers' flux, this could be a potential result.
-PB
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Hi There!
I am 99% sure I didn't use plumbers anything, I bought good quality something or rather from one of the reputable speciality electronics store. The Sound moves from the left ear to the right depending how far the headphone is inserted into the jack, but I don't think I can get it to happen to both sides at the same time.
Wouldn't poor solder or joint cause voltage or resistance issues?
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The reason it changes sides when you move the headphone jack in/out is because the contacts in the socket are touching different contacts in the plug. If you leave jack plugged in fully, which side is the noise on?
Sounds like it might be worth reflowing your solder joints based on PB's assessment of the issue.
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Hi There!
On the right hand side. I'll take a look at the soldering in the next couple of days, hopefully it is an obvious problem.
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Cool. Good luck!
Question for the experts: can an issue that only exhibits in one channel be caused by the power supply? I would have thought that this would exhibit through both channels.
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I believe when the headphone jack is not fully inserted what you are listening to is a mono signal and think that's why the noise you are hearing travels from the right side to both side when moving the headphone jack in and out.
Which may be helpful in isolating the problem to the right channel.
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https://www.dropbox.com/sc/cxhhfm1xkai1y38/AADzvJW4NPezpzZSO691ixeHa
Just checking these are the connections you want me to reflow? When you say reflow, do you mean add more solder to, or just reheat until the solder is liquid?
Not sure if you can see from the pictures if anything is amiss already.
Do I check all voltages and resistances again after?
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Reflowing is just a matter of heating the joint until the solder turns to liquid again and adding solder only if you think it's needed.
As an example of what you are trying to fix in these cases, one of the resistors in my Mainline attenuator looked like it was soldered, but on really close inspection I found a "void" around one of the resistor leads at the joint. Reheating the joint allowed the flux and solder to reflow and this time to make full contact with both leads in the joint.
It's possible to have a "void" in the joint that you can't see so reflowing (making sure all the solder in the joint liquifies and flows) helps to remove any of these that might exist.
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If you have any other tubes to try, plug them in and see if the sound changes at all. If not, it's probably a bad joint.
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Hi There!
Unfortunately I don't have any spare, nor would I know where to start looking to find replacements in NZ. I was considering bringing some in from overseas, but I was waiting to get the Crack and Speedball installed first. I get my soldering iron back tomorrow hopefully.
This is the solder I have used. Hopefully it's ok.
http://www.jaycar.co.nz/productView.asp?ID=NS3013&keywords=solder&form=KEYWORD
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Yeah, that solder looks good.
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Reflowing is just a matter of heating the joint until the solder turns to liquid again and adding solder only if you think it's needed.
As an example of what you are trying to fix in these cases, one of the resistors in my Mainline attenuator looked like it was soldered, but on really close inspection I found a "void" around one of the resistor leads at the joint. Reheating the joint allowed the flux and solder to reflow and this time to make full contact with both leads in the joint.
It's possible to have a "void" in the joint that you can't see so reflowing (making sure all the solder in the joint liquifies and flows) helps to remove any of these that might exist.
Thanks for the explanation. I figured it was that, but I thought I'd check to be sure.
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Could someone please confirm for me that it's ok for those components to touch each other? I presume so since the Amp actually works and voltages and resistances are correct.
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Which components?
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Which components?
Hi There!
I think they are diodes, the black ones in the pictures I posted. There is no metal pins touching other pins, but the diode parts are touching each other a little.
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The black bodies of the diodes can touch, that's OK. You just don't want the metal leads on a pair of diodes touching when they go to different terminals.
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The black bodies of the diodes can touch, that's OK. You just don't want the metal leads on a pair of diodes touching when they go to different terminals.
Thanks, I was pretty aware that was likely so I am pretty sure that's the case, I'll double check tonight.
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Boy oh Boy how the plot has thickened!
Turns out that the problem IS being introduced at the source, if the source is considered the ODAC connected between the Source and the Crack Amp.
I did the reflow and then if anything the problem seemed worse (settled back to normal badness after a bit).
I can't hear anything I would consider abnormal (A bit of staticy type noise when I move the volume on the crack just whilst it's moving) when the ODAC isn't present, but then the sound isn't as good. If I plug the ODAC into the O2 Amp I have, I can't hear anything, so it seems to be some sort of weird compatibility between the ODAC and the Crack.
I apologise for the incorrect information, it's been a few months since I last worked on the issue, and my memory of the troubleshooting has obviously let me down.
Should I start a new thread to address the potential issue between the ODAC and the Crack or just continue?
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How are you powering your ODAC?
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USB. It's the only option.
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You might want to try getting a USB cable with an external power supply, or if you aren't already, try using a laptop running on its battery.
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Hi There!
Ok well, I plugged the ODAC into my laptop and it sounds AWESOME with the CRACK. No noise, nothing. Perfect. Seems there is an issue between the USB on my PC, the ODAC and the Crack. The ODAC guy asked:
"If the Crack amp uses two independent grounds for each channel (rare), perhaps ODAC's common ground creates issues within the Crack Amp"
Is this possible/Likely or is it really now a case of figuring out why my PC USB causes the problem when it doesn't happen with another AMP or even with no amp?
On the plus side, I think this means I made no mistakes whilst building the crack. My grandfather (RIP) would have been so proud. It was him that introduced me to Electronics when I was 8, and bought me my first DIY Electronics kit, with strings instead of solder.
I have been trying to find a place that makes very nice little metal plates (Plaques) I can have laser etched, my dedication of the amp to him, in case anyone knows of a place.
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I have been trying to find a place that makes very nice little metal plates (Plaques) I can have laser etched, my dedication of the amp to him, in case anyone knows of a place.
You might try here
http://www.frontpanelexpress.com/
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Crack uses a common ground between the two channels. Since your laptop is quiet (presumably running on betteries or maybe a two prong power cord) and your PC is not (presuming your PC is plugged ito the wall) there may be a ground loop issue. Is the PC plugged into the same AC mains outlet as the Crack?
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Crack uses a common ground between the two channels. Since your laptop is quiet (presumably running on betteries or maybe a two prong power cord) and your PC is not (presuming your PC is plugged ito the wall) there may be a ground loop issue. Is the PC plugged into the same AC mains outlet as the Crack?
Hi There!
Sort of, My PC is plugged into a 4 Way Zap Catcher, and the Laptop was plugged into another 4 Way Zap Catcher, but eventually they end up in the same wall socket. The Laptop probably is quiet as much because it runs from battery even when plugged in as I understand it.
How do I tell what is not grounded? Is there an easy test? If the Crack wasn't grounded, what would happen? Would it's fuse blow? I have the 240v version.
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Well today I bought a Schiit BiFrost, and low and behold, with USB, the same noise. So it's not the Dac causing the problem. How do I work out if there is a ground loop on the Crack, or on my PC, or somewhere else?
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Well today I bought a Schiit BiFrost, and low and behold, with USB, the same noise. So it's not the Dac causing the problem. How do I work out if there is a ground loop on the Crack, or on my PC, or somewhere else?
Hopefully others will chime in and help here, but I think the issue is in your power supply to the computer and or the USB signal from the computer.
Can you try plugging the DAC and Crack and PC into the same power board and report on the results?
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Hopefully others will chime in and help here, but I think the issue is in your power supply to the computer and or the USB signal from the computer.
Can you try plugging the DAC and Crack and PC into the same power board and report on the results?
I'll try this tomorrow as I got my new Bi-Frost and I am in Musical Bliss right now :)
Not sure if this helps, but plugging into the BiFrost from the the SPDIF also has a slight buzzing noise in the right hand ear. Sadly the base for my crack isn't assembled so moving it, is no easy feat.
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Just a note - ground currents (often called "ground loops") do not occur within a component, but rather between components. That's why they are so hard to trace ... :^)
What happens is there is an AC current in the ground side of the interconnect, and that current drops a tiny voltage because the ground wire has some resistance, and that voltage gets added to the signal.
You can start with the Crack no connected to anything, and the volume turned all the way down. If there is hum, it is within the Crack. (You can then turn the volume up, and detect whether there is electromagnetic interference noise - always good to eliminate other possible problems!)
Then connect the DAC to the Crack, with nothing else connected to the DAC. If you get a new hum/noise then the DAC is likely introducing a noise current into the interconnect ground wire. If the DAC has a two-prong plug you can try reversing it, sometimes this helps. You can also try running the power cables close together for as long a distance as possible, sometimes that helps.
If there is still no noise with the DAC connected to Crack, then connect the computer. The same comments as the above paragraph apply. The computer is likely connected to other line-powered devices such as a router or a printer, so you can try disconnecting them to further isolate the problem.
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Just a note - ground currents (often called "ground loops") do not occur within a component, but rather between components. That's why they are so hard to trace ... :^)
What happens is there is an AC current in the ground side of the interconnect, and that current drops a tiny voltage because the ground wire has some resistance, and that voltage gets added to the signal.
You can start with the Crack no connected to anything, and the volume turned all the way down. If there is hum, it is within the Crack. (You can then turn the volume up, and detect whether there is electromagnetic interference noise - always good to eliminate other possible problems!)
Then connect the DAC to the Crack, with nothing else connected to the DAC. If you get a new hum/noise then the DAC is likely introducing a noise current into the interconnect ground wire. If the DAC has a two-prong plug you can try reversing it, sometimes this helps. You can also try running the power cables close together for as long a distance as possible, sometimes that helps.
If there is still no noise with the DAC connected to Crack, then connect the computer. The same comments as the above paragraph apply. The computer is likely connected to other line-powered devices such as a router or a printer, so you can try disconnecting them to further isolate the problem.
Hi Paul
These are the facts as I understand them right now.
1) Amp with nothing connected - No unusual noise
2) DAC connected to Crack, but no USB Connected - No unusual noise
3) ODAC connected to USB on Desktop Computer, connected to Crack - Noisy
4) Bifrost connected to USB on Desktop, Connected to Crack - Noisy
5) ODAC/BiFrost Connected to Laptop via USB - No Noise
6) ODAC to Headphones directly, connected to PC or Laptop via USB - no Noise
7) BiFrost Connected via SPDIF to Crack - Slight noise - Not as bad as via USB
8) ODAC connected to PC via USB then Connected to O2 AMP - No Noise
9) ODAC Connected to Laptop via USB then Connected to O2 Amp - No Noise
10) Noise from 3 doesn't seem to change as I adjust the volume knob on the crack
11) Noise from 3 doesn't seem to change if I remove one of the RCA's or the other, or if I swap them around
12) Noise from 3 not affected by type of music playing, or sample rate etc.
13) Noise from 3 can be drowned out if the volume is loud enough (Music
14) The Music coming from the crack in 3 sounds Excellent, just the buzz in the background
15) Noise from 3 moves from right hand to left hand depending on how far the headphone is inserted into the jack.
I have tried to troubleshoot this as methodically as I can...
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Excellent data!
I'm going out of town so hopefully PB will pick up this thread, but you have pretty much confirmed (as I see it) that the noise comes from a ground current running from the desktop computer to the Crack ground, which is connected to the power line safety ground. (I assume the O2 has a two-prong power cord and is double insulated instead of being safety grounded.)
If I am right and you can use an optical interconnect to the DAC, that should solve it. That would break the ground current path.
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Yeah, this kind of thing isn't all that uncommon. You could also try a powered USB cable, though that may or may not solve your issue.
The optical connection is a very good option.
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Sound similar to my experiences rerouting of cables and switching to optical interconnect for dac and pc sorted it out.
The hardest noise to trace was a intermittent buzz during the winter in the evenings it was driving me nuts coming and going and turned out to be a electric oil filled radiator in another room tripping in and out on its thermostat. I was running my internet signal through the houses power sockets at the time.
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Ok Additional things I have tried today without any luck:
1) Put the Crack Amp, PC and Dac into the same powerboard. - Noisy
2) Unplugged al PC peripherals, Keyboards, mice, other USB devices (basically nothing except power and Coax SPDIF) - Noisy
3) Switched from SPDIF to Coax Spdif - Noisy
4) Unplugged everythng except headphones and power and turned the volume right up. It's Silent other than some very temporary noise in some parts of the turn, until I am 80% round where I then hear a faint hum
I can't run a powered USB as I don't have one, but given the bifrost is AC powered, and the same thing happens with it, I am inclined to think it wouldn't help.
Is there something I can do with a multimeter to test the crack for a ground loop?
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Ok Additional things I have tried today without any luck:
1) Put the Crack Amp, PC and Dac into the same powerboard. - Noisy
2) Unplugged al PC peripherals, Keyboards, mice, other USB devices (basically nothing except power and Coax SPDIF) - Noisy
3) Switched from SPDIF to Coax Spdif - Noisy
4) Unplugged everythng except headphones and power and turned the volume right up. It's Silent other than some very temporary noise in some parts of the turn, until I am 80% round where I then hear a faint hum
I can't run a powered USB as I don't have one, but given the bifrost is AC powered, and the same thing happens with it, I am inclined to think it wouldn't help.
Is there something I can do with a multimeter to test the crack for a ground loop?
No (to ground loop testing), because there isn't one in the Crack or you would hear noise even with nothing plugged in. The issue you have is occurring outside of your Crack and being transmitted into the Crack via the source devices you're using (i.e. PC to DAC is where the noise is generated).
Can you use optical or is that noisy too (or not available)?
I know some people have tried removing certain power-related pins from USB cables with some success on this type of issue, but I don't know which ones or if it would work for you here. Perhaps someone can elaborate.
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You could try a cheater plug on the PC. A person might be inclined to try a cheater plug on the Crack, but of course as the manufacturer I have to discourage that as it defeats the safety ground in our product.
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Just my 2 cents here...
Don't defeat the safety ground on the crack. Even if it were to fix the issue. Crack -> You -> Ground = bad place to be. Better to fix the ground issues elsewhere.
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You could try a cheater plug on the PC. A person might be inclined to try a cheater plug on the Crack, but of course as the manufacturer I have to discourage that as it defeats the safety ground in our product.
When someone said that ground loop occurs between components, did they mean between two electronic components such as resistors and diodes, or between components being DAC and AMP or PC and DAC?
Given I have tried SPDIF and SPDIF Coax and the problem still exists, I am pulling my hair out.
If I use the headphone jack (6.25) on my Soundcard I can't hear anything and if I use my USB Headset into the PC, I can't hear anything. Unsure if this is useful information.
Is it possible the house itself isn't grounded and is it worth at this stage considering a electrician come to the house?
Any other troubleshooting steps? The PC is pretty huge so moving it isn't really that practical, and the only other PC's are laptops. I could take my Crack and Dac to work and see if it's still a problem, but I imagine it's within my house.
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One thing I wanted to note though I warn up front it COULD be a Red Herring..
I have a pair of RS170 Headphones, Wireless, made by sennhiesser and I have long had an issue with a hum in those, whenever sound wasn't playing. So when I watch TV, plugged into the Headphone Jack of the TV, whenever speech or music isn't play, say between scenes or if there is a long pause in conversation the hum/buzz appears, but goes away when speech/music resumes.
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When someone said that ground loop occurs between components, did they mean between two electronic components such as resistors and diodes, or between components being DAC and AMP or PC and DAC?...
I said that, and I meant there was a noise current in the ground wire of the interconnect between two devices - specifically, with all the great information you have obtained, everything points to a current in the ground ware of anything that connects between the computer and anything else that is safety grounded.
When I say "safety grounded" I mean that the chassis and the signal ground are connected to the third pin of the power socket.
It's sooo hard to be clear with just words! Sorry for the lack of clarity. Computer power supplies are notorious for being noisy in several ways, this is just one of them. I think the computer power supply produces an output whose ground side is not bonded tightly (i.e. with low resistance) to the signal reference ground used for SPDIF, headphones, USB, or other outputs.
When you connect something that is not itself grounded to safety ground, that "something" has a ground which fluctuates with the computer ground. You listen to the difference between the "ground" and the "signal" which both fluctuate the same way and there is no apparent hum. It's only when the Crack or another safety-grounded device provide a path for that fluctuating voltage to generate a current (into the safety ground) whic causes the non-zero resistance of the interconnect to acquire some noise.
If you can get the digits to the DAC without a ground wire, there will be no current and no noise. That's why I suggested an optical link, but wifi or bluetooth would do the same. Failing that, a transformer between the DAC and the Crack is a traditional solution; the two windings are connected magnetically but not electrically. Unfortunately it can be expensive to get good transformers. At one time Radio Shack sold some inexpensive audio transformers to solve the same kind of problem in car audio installations, they were cheap but they were cheap if you get my drift.
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If you can get the digits to the DAC without a ground wire, there will be no current and no noise.
Paul, is this why some people suggest removing the power-related pins from the USB cable if the DAC is self-powered or is the noise carried in the digital audio signal itself?
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Could be - I'm not knowledgeable on that hack!
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Hi,
People have referred to the problem being eliminated by an optical cable, but as I understand it, that has already been tried by trying both SpDIF and SpDIF Coaxial, correct?
If the problem has persisted beyond this, then does this lead us to different steps in troubleshooting, or a more clear picture as to where the problem lies? The BiFrost has a 3 Pin power, the PC does and the Crack Amp. This means they are all grounded as I understand it.
Sorry if I still don't get it, it doesn't really make sense to me.
If Current is getting into the ground wire for one of these devices, wouldn't a current check or something allow us to determine if that is coming from the Crack?
The ODAC is USB powered, but the BiFrost is independently mains powered.
Given the O2 amp is 2 pin powered via mains and I can't hear any noise via that, then would it not indicate, the only conclusion is my PC has the issue?
If Categorically, I could hear if there was a problem with the crack amp, then it really only leaves the PC as the common denominator ? Do I need to pull my PC apart to see if I have a short or something?
Houses in NZ are supposed to be grounded too, wondering if that perhaps isn't the case with our place for some reason. Perhaps the grounding bar isn't connected properly? If that was the case I presume then that all my audio equipment in the lounge would be humming?
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SPDIF Coax still creates an electrical connection, optical does not.
It sounds like a USB isolator might solve your problem as they remove any direct electrical connection between the PC and USB device. They also have their own 5v power supply which is a lot cleaner than the 5v supply coming out of a PC. For a USB powered DAC this can make all the difference in terms of noise floor.
Up to now USB isolators were a DIY thing in that you had to cobble it together yourself, i built one of the Ciruits@home kits and put together a linear power supply for it. The guys at Beezar are just about to release a complete kit, i have built and tested one of their pre-production prototypes and can confirm it performs perfectly. Keep an eye on the thread as it should be available to order very soon.
Main thread here https://www.head-fi.org/t/703334/doodlebug-usb-isolator (https://www.head-fi.org/t/703334/doodlebug-usb-isolator)
Pics of my unit here https://www.head-fi.org/g/i/1091976/beezar/sort/display_order/ (https://www.head-fi.org/g/i/1091976/beezar/sort/display_order/)
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SPDIF Coax still creates an electrical connection, optical does not.
It sounds like a USB isolator might solve your problem as they remove any direct electrical connection between the PC and USB device. They also have their own 5v power supply which is a lot cleaner than the 5v supply coming out of a PC. For a USB powered DAC this can make all the difference in terms of noise floor.
Up to now USB isolators were a DIY thing in that you had to cobble it together yourself, i built one of the Ciruits@home kits and put together a linear power supply for it. The guys at Beezar are just about to release a complete kit, i have built and tested one of their pre-production prototypes and can confirm it performs perfectly. Keep an eye on the thread as it should be available to order very soon.
Main thread here https://www.head-fi.org/t/703334/doodlebug-usb-isolator (https://www.head-fi.org/t/703334/doodlebug-usb-isolator)
Pics of my unit here https://www.head-fi.org/g/i/1091976/beezar/sort/display_order/ (https://www.head-fi.org/g/i/1091976/beezar/sort/display_order/)
Hi There!
If Optical is also know as Toslink, then I have tried this and I still have the buzzing. so I have the problem via Toslink, Spdif over Coax, and USB. How much do you think that Isolater will cost roughly?
A lot of these type of suggestions, seem to be a workaround, I would be interested in solving the problem itself, as usually these things can affect more than one thing.
I bought this today, it gets to me tomorrow. I am hoping it's going to work!
http://www.trademe.co.nz/Browse/Listing.aspx?id=740393126
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Houses in NZ are supposed to be grounded too, wondering if that perhaps isn't the case with our place for some reason. Perhaps the grounding bar isn't connected properly? If that was the case I presume then that all my audio equipment in the lounge would be humming?
Hi, I live in NZ too. The electrical grounding system here is required for the safety of human life. If your house wiring is no longer correctly grounded then it will be in a dangerous state. If you suspect that is the case then you should get an electrician to check it out. For this reason never let anyone convince you to "lift the ground" or use a 2-pin AC plug in place of a 3-pin plug to disconnect the safety ground. The suggested signal-level ground isolators are the safe way to proceed.
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Hi, I live in NZ too. The electrical grounding system here is required for the safety of human life. If your house wiring is no longer correctly grounded then it will be in a dangerous state. If you suspect that is the case then you should get an electrician to check it out. For this reason never let anyone convince you to "lift the ground" or use a 2-pin AC plug in place of a 3-pin plug to disconnect the safety ground. The suggested signal-level ground isolators are the safe way to proceed.
I don't really think that is the case, it was just a theory from the guy at work.
I am puzzled by the comment the problem shouldn't occur over optical but it does. Perhaps we are all barking up the wrong tree.
Below is a picture of the PSU section of my AMP. Perhaps you would be prepared to post yours for comparison:
https://www.dropbox.com/s/xeehllzo0j18x0w/20140615_202252.jpg
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I just got a lucky break. Not sure how I did it, but I was taking a photo of the Amp up closer and just got 240v right through the chest. (well that's where I felt it). Somehow I completed a circuit but I don't recall doing it. Crack was off, but power cable was in (was just a quick peek, but I learned my lesson but good).
So stupid, but luckily, still alive. Thankfully alive to learn that lesson.
Unfortunately I jumped back and let go of the crack so some stuff got a little bent, so I guess tomorrow, I'll need to redo all the resistance and voltage checks again, how annoying.
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If Optical is also know as Toslink, then I have tried this and I still have the buzzing. so I have the problem via Toslink, Spdif over Coax, and USB. How much do you think that Isolater will cost roughly?
So with the Toslink connection, you have hum with the laptop plugged in and no hum with the laptop on batteries?
I would triple check this situation, the Toslink cable should work.
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I just got a lucky break. Not sure how I did it, but I was taking a photo of the Amp up closer and just got 240v right through the chest. (well that's where I felt it).
I picked up the crack about a couple months ago while I was upside down while testing. My thumb apparently got to close to the AC socket. I felt that climb right up into my shoulder. NA is only 110-120VAC, but it will still get you if you dead short.
Unfortunately I jumped back and let go of the crack so some stuff got a little bent, so I guess tomorrow, I'll need to redo all the resistance and voltage checks again, how annoying.
My use the supplied 6080 and 9 pin when testing, as they are both 'cheap' compared to some of the other tubes I have. Just the some of the 12AU7 pins bent for me, which is trivial. More upsetting was my own stupidity - evidenced by a long stream of curses I didn't think even I still knew.
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So with the Toslink connection, you have hum with the laptop plugged in and no hum with the laptop on batteries?
I would triple check this situation, the Toslink cable should work.
In my case my toslink (cheap five dollar job) seems to work as good as or better than the USB option on my DAC. I've tried expensive glass toslink, only to see it not be able to sync up at 192K, where as the plastic seem to couple better with the diodes on my motherboard. *shrug*
But Paul is correct, a toslink cable should provide electrical isolation from the computer in the chain.
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So with the Toslink connection, you have hum with the laptop plugged in and no hum with the laptop on batteries?
I would triple check this situation, the Toslink cable should work.
I don't have any noise from the laptop to anything. The issue is from my Desktop PC via any DAC to the Crack. I have tried Toslink, Spdif over coax and USB and all of them present with noise.
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I picked up the crack about a couple months ago while I was upside down while testing. My thumb apparently got to close to the AC socket. I felt that climb right up into my shoulder. NA is only 110-120VAC, but it will still get you if you dead short.
My use the supplied 6080 and 9 pin when testing, as they are both 'cheap' compared to some of the other tubes I have. Just the some of the 12AU7 pins bent for me, which is trivial. More upsetting was my own stupidity - evidenced by a long stream of curses I didn't think even I still knew.
Hi There!
I think everything is still intact thankfully. I will do the testing tonight. I don't recall touching anything in a way to make a circuit and I am wondering if I have something incorrectly wired around the ground, though voltages and resistance checks were bang on the three times I checked it so perhaps I just don't recall the reality.
My wife is a little concerned that the bottom of this crack isn't sealed and we have little kids one of whom is particularly inquisitive, so I need to be quite careful where I leave it etc.
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Hi There!
I think everything is still intact thankfully. I will do the testing tonight. I don't recall touching anything in a way to make a circuit and I am wondering if I have something incorrectly wired around the ground, though voltages and resistance checks were bang on the three times I checked it so perhaps I just don't recall the reality.
My wife is a little concerned that the bottom of this crack isn't sealed and we have little kids one of whom is particularly inquisitive, so I need to be quite careful where I leave it etc.
After checking your wiring, you might want to attach some sort of open grille / mesh to the bottom of your Crack to prevent little fingers (and big ones) going where they shouldn't.
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A suggestion: When you re-try the Toslink optical interconnect to isolate the DAC from the PC, make sure that no other wired interconnects are plugged in at all between them, e.g. unused coax, analogue, USB. If they are, they will still probably couple the noisy ground of the PC to the DAC. The ground shields will still electrically connect, even if they aren't selected by the DAC input.
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A suggestion: When you re-try the Toslink optical interconnect to isolate the DAC from the PC, make sure that no other wired interconnects are plugged in at all between them, e.g. unused coax, analogue, USB. If they are, they will still probably couple the noisy ground of the PC to the DAC. The ground shields will still electrically connect, even if they aren't selected by the DAC input.
Hi There!
I never have more than one connected at a time.
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After checking your wiring, you might want to attach some sort of open grille / mesh to the bottom of your Crack to prevent little fingers (and big ones) going where they shouldn't.
My son is 5, about to be 6. I simply told him never to touch it, as he could accidentally get a shock and quite possibly die. Explained you have to know what you are doing before you touch it, don't play in this room. Etc.
He gives it a wide birth. :P
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Hi There!
I never have more than one connected at a time.
Any chance that your toslink cable for some reason is 'shielded'?
http://www.amazon.co.uk/Horizon-Professional-Performance-Protection-equipment/dp/B005ELLH0W
The above is not shielded, but there's no call for any metal at all on a toslink cable!
Mine is plastic.. cheap cheap cheap. Sears. $5. Works great.
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My son is 5, about to be 6. I simply told him never to touch it, as he could accidentally get a shock and quite possibly die. Explained you have to know what you are doing before you touch it, don't play in this room. Etc.
He gives it a wide birth. :P
My SON is completely safe. He is the most sensible kid and always listens and obeys, I've never had him near a single thing in 4 years which I've asked him to avoid. It's my daughter who is 2.5 who is my primary worry. She will SOMETIMES listen, but sometimes isn't the margin of error I'd accept at 240v :)
She is getting a little better, but some days she drives me crazy getting into stuff.
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Any chance that your toslink cable for some reason is 'shielded'?
http://www.amazon.co.uk/Horizon-Professional-Performance-Protection-equipment/dp/B005ELLH0W
The above is not shielded, but there's no call for any metal at all on a toslink cable!
Mine is plastic.. cheap cheap cheap. Sears. $5. Works great.
I have about 6 of them, I'll try some of the others.
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Okie Dokie. Resistance check has been recompleted after I dropped it.
T1 : 4M
T2: 3M
T3: 0.3ohms
T4: 70K-3.7M
T5: 4-5M
T6: 2.5K
T7: 2.9K
T8: 0 ohms
T9: 2.9k
T10: 2.2K
T12: 0.4ohms
T13: 30M went to 40K then climbed to 270K
T14: 0 ohms
T20: 0.3 ohms
T22: 0.3 ohms
B3: 2.9K
B6: 2.9k
RCA Ground Lug 1 (Black): 0.2ohms
RCA Ground Lug 1: (Red): 93K
RCA Centre Pin 1 (Black): 0.2ohms
RCA Centre Pin 2: (Red): 98k
So the things I wanted to check are:
I did this with the fuse in, but obviously not the power or the tubes, are these results ok ?
RCA results are slightly off 90k but are different? OK ?
Most of the 0 result ones are marginally off, is this ok, or they HAVE to be 0.0 and what should I do if that's the case?
T1 and T2 and T13 OK?
I wanted to do the grounding checks that someone had pasted earlier given the issues I have had with a grounding loop and electrocuting myself (Which I now believe was because I accidentlly touched the IEC and the metal base at the same time.), prior to putting on the power and doing voltage checks.
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I thought they were ok. Proceeded with Voltage checks.
1: 83
2: 161
3: 1.6mV
4: 160
5: 80
6: Variable
7: 105
8: 1mV
9: 104
10: 5mV
11: 2mV
12: 0
13: 162
14: 0
15: 182
20: 0.5mV
21: 202
A1: 80
A2: 1.8mV
A3: 1.5
A4: 1.9mV
A5: 1.9mV
A6: 84
A7: 0.8mV
A8: 1.64
A9: 1.64
B1: 82
B2: 160
B3: 105
B4: 81
B5: 161
B6: 104
B7: 2.1mV
B8: 2.1mV
OK?
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Looks like you have a working amplifier.
-PB
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Looks like you have a working amplifier.
-PB
Thanks. What would be the reason for the low numbers instead of 0 at some of the voltage check points like t12?
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5mV is 0.005V, which is pretty close to 0. This is one of those things that will just vary a bit from meter to meter, as well as from terminal to terminal.
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Thanks CB.
So a new development. I now have buzzing which exists whether I have a DAC plugged in at all, and only exists after the headphone is about 75% of the way fully inserted in the jack. It seems to have changed and become louder for a few seconds and then went back to a basic buzz. It seems to vary a fair bit and I can affect it by moving around, but not consistently.
Any ideas?
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Gentle Bump. Sorry guys, you have been so helpful so far, but I just don't know what could be causing the buzzing :)
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So a new development. I now have buzzing which exists whether I have a DAC plugged in at all, and only exists after the headphone is about 75% of the way fully inserted in the jack. It seems to have changed and become louder for a few seconds and then went back to a basic buzz. It seems to vary a fair bit and I can affect it by moving around, but not consistently.
So, the hum does exist with the headphone all the way in?
Is the amp still quiet receiving music from your phone through a 1/8" to RCA cable?
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When you say you can vary it a bit by moving around, what is moving - the amp, parts inside the amp, or you? Usually buzz is from a cold solder joint to ground.
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When you say you can vary it a bit by moving around, what is moving - the amp, parts inside the amp, or you? Usually buzz is from a cold solder joint to ground.
If *I* Move around (Wave my arms or move closer or further from the AMP) (Amp and everything else except the headphone cable are static). It's very weird.
The noise from the original topic isn't apparent as best I can tell presently.
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So, the hum does exist with the headphone all the way in?
Is the amp still quiet receiving music from your phone through a 1/8" to RCA cable?
The Hum Exists with the plug all the way in, but not if it's some of the way out of the plug as best I can tell. (Not sure if you know what I mean but there are stages that the plug will go in). It exists if I remove the RCA Plugs from the Amp completely (As in no source attached.
If there was a cold joint, would this not cause voltage and resistance irregularities?
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The Hum Exists with the plug all the way in, but not if it's some of the way out of the plug as best I can tell.
If there was a cold joint, would this not cause voltage and resistance irregularities?
The only relevant test is with the plug all the way in, otherwise you short some connections together that give you erroneous readings.
A cold solder joint rarely shows up in resistance readings, sometimes will show up in voltage readings, but often enough appears in neither.
My test for a cold solder joint is to jostle the piece of equipment pretty roughly while I'm listening to it. Cold solder joints will announce themselves with crackling or popping. Of course, the easiest method to be sure is to reheat all your solder joints.
-PB
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The only relevant test is with the plug all the way in, otherwise you short some connections together that give you erroneous readings.
A cold solder joint rarely shows up in resistance readings, sometimes will show up in voltage readings, but often enough appears in neither.
My test for a cold solder joint is to jostle the piece of equipment pretty roughly while I'm listening to it. Cold solder joints will announce themselves with crackling or popping. Of course, the easiest method to be sure is to reheat all your solder joints.
-PB
When you say piece of equipment I presume you don't mean electronic component? Touching things like capacitors and the like could be pretty dangerous I would have thought?
Given this is a buzzing rather than a crackling is the same solution recommended? Are there some components more likely to be causing that buzzing than others?
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You use a non conductive tool to probe and wiggle the components. A chopstick works well. Anything plastic or wood that doesn't have metal on the end can be used to push on the various parts to see if it changes the sound. Use all of the proper safety procedures, support the inverted chassis so it is stable before you apply power, don't touch it with your bare hand.
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Bit of a wildcard but I spent two hours last night trying to troubleshoot a noisy Crack (static like buzzing even with nothing connected to it but headphones that I could overcome by cranking up the volume of the music) only to find that it was picking up interference from a Powerline Network Adapter I had plugged into a wall socket in the opposite corner of the room... With the Powerline Network Adapter unplugged everything was silent!
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Hi There!
I wanted to post back and let you know I am now listening to a silent crack amp, after having given up and taking it to an electronics engineer I found in a local forum.
It took him about 20 minutes to find the problem and only after he went through step by step in the manual did he find that I had connected but failed to solder 2 of the connections on page 19 of the manual (I could get the numbers exactly of which tags, but it's on and would be hot to turn over. He summarized it was allowing a ground loop. It also explained why moving the amp to my office changed the sound as the car movement probably moved the connection slightly.
On the plus side he said with 1 exception he found my soldering to be better than a lot of the graduates with project work experience he had seen, he was pretty impressed.
It was a little frustrating to have it turn out to be this as I had been over the amp at least 20 times looking for bad solder joints but sometimes the more you look the worse it gets.
I am just glad to be over this hurdle. I am trying to now decide if I should listen to it more or move to the Speedball upgrade this weekend.
I am also wondering if there are other upgrades I should add now before the speedball which will be much harder once the speedball is in.
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Wow - cool story, thanks for posting! Yeah, reality is like that - we've all been there, even if we don't always admit it!