Scratchy/distorted sound with Linux

Hi, I don’t know where you are in the QA process, or if this is the right place to put this, but I noticed a sound issue on the Linux version.

First of all, amazing work getting it to run on several platforms at once. I tried it on three machines, or that is to say one laptop and one desktop running two different operating systems. The linux desktop has an interesting issue. The sound comes out very noisy and distorted, like very scratchy and just wrong. I can “fix it” by changing outputs, that is, different outputs, like changing from headphone digital to headphone analog, etc. That makes it work, but then I change the preset and it is wrong again.

The interesting part is running a different operating system (Windows) with vital on the exact same hardware works fine. The combinations I have tried:

linux (ubuntu 20.04) laptop - works
Linux (ubuntu 20.04) desktop - has the issue.
Windows 10 desktop - works.

Note the desktop is a new, high end Ryzen (16 core) with plenty of memory and a high end graphics card, so don’t think performance is an issue there.

I do a lot of audio work myself, and I have had similar issues because of buffer overruns/underruns. If you are using ALSA, that is a fairly touchy subsystem.

Anyways, that’s my issue report.
Again, great product, enjoying it a lot.

Scott Franco
San Jose, CA

One more data point: It only occurs on my Razor headset, which has its own USB audio dongle that drives it. The main speaker is driven by a soundblaster Audiology RX and does not have the issue.

Also tested with same Razor headset on windows, no issue.

I reply just to give some comparison information.

I run Ubuntu Studio 20.04, with 5.4.0-72-lowlatency kernel, and I have not had any such issues. I have tried my two USB audio devices: M-Audio Fast Track II, and Mackie Big Knob Studio+.

I use a Jack buffer size of 512 at 48KHz.

System is AMD Ryzen 3900X 12-core CPU, 64Gb RAM, GTX 1080Ti.

Is that buffer size something I could tweak?

@samiam: Sure, you could do it in QJackCtl. But I’m not sure Jack is installed in a vanilla Ubuntu system, and then it falls down to ALSA, I guess.