Hello !
I have a problem with my parasound zdac (Product Lines > Parasound Z > Zdac - Digital to Analog Converter). It’s working fine, but sometimes, and randomly, I can get a huge constant distortion (heart attack during night listening), or just nothing. In order to get my music back, I have to power on/off the DAC, sometimes a few times.
It can happen in the middle of a song (foobar2000, with or without wasapi) or on youtube (probably while changing play time). On windows 7/10, different PCs, android tv box. In different houses, with different power/usb cables.
Do you think I can do something to solve this problem ? I was thinking of using a CM6631A in order to use coaxial input instead of usb ?
Thank you for your help
I have a problem with my parasound zdac (Product Lines > Parasound Z > Zdac - Digital to Analog Converter). It’s working fine, but sometimes, and randomly, I can get a huge constant distortion (heart attack during night listening), or just nothing. In order to get my music back, I have to power on/off the DAC, sometimes a few times.
It can happen in the middle of a song (foobar2000, with or without wasapi) or on youtube (probably while changing play time). On windows 7/10, different PCs, android tv box. In different houses, with different power/usb cables.
Do you think I can do something to solve this problem ? I was thinking of using a CM6631A in order to use coaxial input instead of usb ?
Thank you for your help
Well, not really. But it seems that the problem comes directly from the DAC. I'm not sure, that's why I'm here !
Have you considered sending in and getting a quote for repair?
Support << Parasound
I ask because fixing it could be complicated and you might risk damaging it worse by trying. If you had a schematic or a service manual for it that would probably make it a lot easier to try to repair.
You could open it up and and look for any loose wires, cracked solder joints, or electrolytic capacitors with bulged out ends. You could find some test points to measure power supply voltages with a DVM, then wait until the problem happens and see if any voltages have changed. You could try hitting components inside with some freeze spray and see if you can get the problem to start when you want, or if you can get the problem to stop (after it starts acting up on its own) without power cycling it.
In other words, the kinds of things people sometimes do for troubleshooting when they don't have any service documentation. You could try downloading and reading data sheets for the main components to see how much you can figure out about how it is supposed to work, and maybe see if there are good points to test or look at with an oscilloscope (if you have one).
If you want you could post some very hi res photos of the insides. The pictures should be clear enough to read part numbers off the chips, and to examine solder joints. You might have to take a big picture of each side in lower res, the take some close ups in higher res. Reason I suggest that is there a limit on file size of pictures you can post here. So you have work with that somehow. No guarantee it will help get the problem solved, but a few people would probably willing to take a look.
Support << Parasound
I ask because fixing it could be complicated and you might risk damaging it worse by trying. If you had a schematic or a service manual for it that would probably make it a lot easier to try to repair.
You could open it up and and look for any loose wires, cracked solder joints, or electrolytic capacitors with bulged out ends. You could find some test points to measure power supply voltages with a DVM, then wait until the problem happens and see if any voltages have changed. You could try hitting components inside with some freeze spray and see if you can get the problem to start when you want, or if you can get the problem to stop (after it starts acting up on its own) without power cycling it.
In other words, the kinds of things people sometimes do for troubleshooting when they don't have any service documentation. You could try downloading and reading data sheets for the main components to see how much you can figure out about how it is supposed to work, and maybe see if there are good points to test or look at with an oscilloscope (if you have one).
If you want you could post some very hi res photos of the insides. The pictures should be clear enough to read part numbers off the chips, and to examine solder joints. You might have to take a big picture of each side in lower res, the take some close ups in higher res. Reason I suggest that is there a limit on file size of pictures you can post here. So you have work with that somehow. No guarantee it will help get the problem solved, but a few people would probably willing to take a look.
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Hello
Thank you for your answer. I would like to repair it myself if possible. But I don't have a lot of stuff except a soldering iron...
Anyway, here are the hi res photos (.pdf) : https://mega.nz/#!gEUUUSqK!Z24fqyLIfbFYyhwkJTWbxgNlwkGBDQnc91Vw2yCJtf4
I forgot to mention that this distortion issue happened shortly after the purchase (brand new). First times, I thought it was PC related and not DAC related.
Thank you for your answer. I would like to repair it myself if possible. But I don't have a lot of stuff except a soldering iron...
Anyway, here are the hi res photos (.pdf) : https://mega.nz/#!gEUUUSqK!Z24fqyLIfbFYyhwkJTWbxgNlwkGBDQnc91Vw2yCJtf4
I forgot to mention that this distortion issue happened shortly after the purchase (brand new). First times, I thought it was PC related and not DAC related.
The mains cabling runs across the whole DAC...and in parallel with the microphone cables between DAC board and (what appears to be) the headphone amp with the volume pot. That is really bad - verging on shocking. In addition, they also have mains termination (screws) board right next to the headphones' PCB... simply unbelievable.
The noise induced, by keeping the mains' wiring so close to the microphone cabling shield, will affect the PCB ground noise where the sensitive electronics are located, which in turn will cause a serious degradation in noise performance / dynamic range. In addition, you also may experience the USB audio interface disconnection WHILE the DAC is still processing the signals (it is not in a mute state!) - which will cause a terrible noise.
Yeah. One can tell it isn't really a very good dac by looking at what is inside. That's kind of aside from trying to fix it. They may all have exact same wiring layout, so I wouldn't necessarily assume that's where the problem is. However, examining wires and connections carefully is probably not a bad idea. If nothing of immediate danger is found, then pushing on wires and connectors with a plastic stick might or might not elicit some symptoms.
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The blue line refers to the cable in question
The red line shows how it should be laid out; as close to the metal chassis as possible, underneath the headphone and mains' switch PCB's, and away from the DAC PCB
The yellow line shows how the cable could be shortened by 60-70% if you rotate the transformer by 90 deg clockwise - this would be by far the best option; the mains cable, in this case, would not affect the noise performance of the DAC - it would cross the sensitive microphone cables at a right angle
The red line shows how it should be laid out; as close to the metal chassis as possible, underneath the headphone and mains' switch PCB's, and away from the DAC PCB
The yellow line shows how the cable could be shortened by 60-70% if you rotate the transformer by 90 deg clockwise - this would be by far the best option; the mains cable, in this case, would not affect the noise performance of the DAC - it would cross the sensitive microphone cables at a right angle
I could disconnect the headphone amp part, I'm not using it.
Could it be only USB related ? If I use spdif input, same issue ?
Let's do this.
Thanks for thoses lines ! If I remove the headphone amp part, I should be able to be close to the red line.
Once again, it's very random. Sometimes, I can use the DAC 1 month before it happens
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