Dac/amp Disconnecting

[phillip559]

I am not sure this is the right place, but I have a problem. I have a Topping a30 Pro and Schiit Modius. Connected via USB to my PC running Windows 10. Dac and amp are connected via 6in xlr.

My audio keeps disconnecting. The amp turns off for a second or two and then turns on. Generally at somewhat higher volume, but has happened at a lower volume level too. I typically listen to music and game.

I have tried a shorter USB cable, running off of dedicated power, switched a power setting for USB power management, and basically every troubleshooting method. Pretty sure it is dac related because it never happened when I was running just the amp for a month or so.

Any help is greatly appreciated. Thank you!

 

[tomb]

I'm not certain you've tried every troubleshooting method, or you would be able to eliminate either the DAC or the Amp. Can you connect the amp into something else? If not, have you tried connecting the Schiit to the Topping via RCAs? At least that would narrow it down to some issue with the XLR connections.

USB cables are not going to cause the amplifier to turn on and off.

This is a wild guess, but Schiit DACs are known to have outputs too high. It may be possible that the DAC is forcing the amp into a power regime it's not capable of, so it sets off an internal circuit breaker until it cools down, then turns back on. Or the amplifier is simply going bad and your beginning use of the Schiit DAC is a coincidence.

 

[phillip559]

When I run a 3.5mm PC output ito RCA input into the AMP, it never has this problem. I will try connecting the DAC and AMP via RCA when I get home tonight.

If it is a power issue from the DAC, I assume I will need a new DAC? If it is a power issue, would it have the same behavior for RCA and XLR?

Thank you for the reply!

 

[tomb]

When I run a 3.5mm PC output ito RCA input into the AMP, it never has this problem. I will try connecting the DAC and AMP via RCA when I get home tonight.

If it is a power issue from the DAC, I assume I will need a new DAC? If it is a power issue, would it have the same behavior for RCA and XLR?

Thank you for the reply!

Schiit should stand behind it, even if you purchased it second-hand ... I would think.

If there is no issue with the RCA, then that narrows things down to the balanced connections (XLR). You could probably reject the idea that it's power supply related. To truly narrow it down to the specific component, you'd have to find either a different balanced amp, or a different balanced DAC. One should confirm proper operation of the other. This is all assuming you have no issue with the RCA connections.

 

[phillip559]

Well, it does it with RCA as well. Not as often though. It only did it one or two times on RCA. With XLR it would do it up to three times per song. So, pretty much, I need a new DAC?

 

[tomb]

Well, it does it with RCA as well. Not as often though. It only did it one or two times on RCA. With XLR it would do it up to three times per song. So, pretty much, I need a new DAC?

Did you confirm the amp is OK with other sources? I know you said you ran it for a month or so without issue. However, your amp is the thing that's cutting on and off, not the DAC. You should suspect the amp, not the DAC. Another component, either DAC or amp, should prove this out.

 

[phillip559]

I bought another DAC and it resolved the dropping out issue. However, I am having a problem with the DAC and USB. I have a Topping D30 Pro now, and it does not drop out at all. The new problem is a slight popping noise and sometimes distortion. I noticed a song distorting pretty bad, but turned it off and it went away. It did it again, and I turned it off and it went away. There is an audible popping when I slide the volume slider on my PC while the sound notification is playing. If I slide the volume up and down when the computer does the "bing" noise, it slightly pops. The Schiit Modius does not do this, and the D30 Pro only does this when connected via USB. I tried my setup using a laptop and it did the same thing. Tried a different USB cable, but the same thing.

Topping D30 + A30 Pro connected via USB (XLR, RCA) = intermittent distortion and audible popping in headphones when sliding the volume slider
D30 + A30 connected to laptop via USB = same problem ^
D30 + A30 connected via optical = no problem
Schiit Modius + A30 Pro (XLR, RCA)= intermittent dropping out but no intermittent distortion

Went from one problem to the next... :/ the owner of the DAC I bought is in open contact with me and still has at least six months on the warranty. Seems like Topping warranty is owner transferrable too... hopefully it is an easy fix though lol

 

[tomb]

I bought another DAC and it resolved the dropping out issue. However, I am having a problem with the DAC and USB. I have a Topping D30 Pro now, and it does not drop out at all. The new problem is a slight popping noise and sometimes distortion. I noticed a song distorting pretty bad, but turned it off and it went away. It did it again, and I turned it off and it went away. There is an audible popping when I slide the volume slider on my PC while the sound notification is playing. If I slide the volume up and down when the computer does the "bing" noise, it slightly pops. The Schiit Modius does not do this, and the D30 Pro only does this when connected via USB. I tried my setup using a laptop and it did the same thing. Tried a different USB cable, but the same thing.

Topping D30 + A30 Pro connected via USB (XLR, RCA) = intermittent distortion and audible popping in headphones when sliding the volume slider
D30 + A30 connected to laptop via USB = same problem ^
D30 + A30 connected via optical = no problem
Schiit Modius + A30 Pro (XLR, RCA)= intermittent dropping out but no intermittent distortion

Went from one problem to the next... :/ the owner of the DAC I bought is in open contact with me and still has at least six months on the warranty. Seems like Topping warranty is owner transferrable too... hopefully it is an easy fix though lol

1. Don't ever adjust the volume through your OS. It re-interpolates the resolution in the music stream. You should adjust volume with an analog component, only (e.g., volume control on an amp).

2. Popping and distortion as you describe is most often an issue with the drivers. If your DAC did not require drivers, it could be in the USB implementation that the DAC is using, making it more susceptible to digital issues in the USB stream. The best scenario is when you use WASAPI. Make certain your PC's music player has the ability to select the DAC driver and use WASAPI. Foobar2000 and MusicBee are good choices, although I much prefer MusicBee after using Foobar for many, many years.

Even if the drivers are inherent in the OS for your particular DAC, it won't default to WASAPI. WASAPI is the one USB driver that bypasses the OS. Everything else will go through the Windows audio, which will enforce corrections and other interpolations, depending on whatever is going on in the OS at any given moment. Not only will you notice higher quality in the music with WASAPI (assuming your equipment will reveal it, some won't), but it will reduce the driver issues. Another tip is to run your music player in Exclusive mode. This may also help in removing the popping or other potential driver issues. It will also reduce dropouts, if you happen to have a somewhat older/slower PC/laptop.

I've never been able to get Foobar2000 to truly run in exclusive mode, which is one of the reasons I switched to MusicBee. Any other audio app will still operate for me when I set Foobar to exclusive mode. You can't even see YouTube videos with MusicBee, because they try to access the PC's sound, so I know exclusive mode works with MusicBee.