thank you very much for your reply.

i have had the adi-2 dac fs running ok without dropouts via spdif on PC windows 10.
i have also had it running ok without dropouts via usb on a mac.
BUT, and its a big BUT!...
it just doesn't sound anywhere near as crystal as running it through usb on windows 10 / usb.
where i can upsample the sound to 192k via the drivers - except im still getting dropouts and
the occasional distortion.
i have since been on a 3 month journey trying absolutely every fix i can find in windows 10.
surely someone else is also experiencing this? is it not a common issue?

rsvp with any more help and advice would be greatly appreciated.

Just wanted to clarify that, even with the RME driver removed and using the Windows driver, the Tidal desktop app is not bit perfect with USB and the RME DAC. The Windows mixer will resample the signal.

In order to get Tidal bit perfect with USB a third party app such as Audirvana or Roon must be used.

If qobuz is available in your country, the qobuz desktop app supports WASAPI and ASIO bit perfect output. Qobuz also offers CD quality and Hi-res quality FLAC. No MQA nonsense. Qobuz is also $5.00 per month less depending on your location.

Windows Audio Endpoint Bulder is a single thread process, so it can not use more than 100% of one core (!) - not your total CPU. Then you could not use your computer anymore. That said WAEB is not controlled by RME or our drivers as such, which you have already proven by removing those. Sometimes it freaks out because of the motherboard Realtek soundcard drivers and extensions. That's not our problem and nothing we can change.

There is most likely a process happening in the background that is causing the problem. Your PC isn't suitable for processing real-time audio. You could try using an app called LatencyMon or DPC Latency Checker to see what process is causing the problem.

There are a couple apps you could try to see if your PC is suitable for processing real time audio.

DPC Latency Checker - https://softfamous.com/dpc-latency-checker/

LatencyMon - https://www.resplendence.com/latencymon

More info here - https://www.sweetwater.com/sweetcare/ar … cy-issues/

Hopefully, combined with Task Manager, you'll be able to determine what process is causing the issue.

Edit: Another thing you could try is a Clean Boot to see if a driver is behaving badly and causing latency spikes.

https://support.microsoft.com/en-us/top … 7a1807f3dd

I am a software developer of some widely used audio software. In my spare time I also contributed to a few music players’ code. Here is something normal people don’t know— most audio application use a callback function to play music, and that callback function needs to be lock free. Unfortunately most of the widely used applications (such as VLC) are poorly written by inexperienced developers, and locks are introduced in the playback function (because that’s the easiest approach to producer consumer problem). Such program will have performance issues.  It may not take full amount of CPU, but just sitting there waiting for the lock to be released.

In those systems, when you play higher than normal (such as higher than 48khz 16bit) resolution music, you hear hiccups. Usually hi res music is not tested on those systems. Those systems are written for normal people, not for pros or audiophiles.

Some hardware systems are poorly designed (such as some computer motherboards, or raspberry pi’s before version 4 which has problem handling IRQs real-time). As a result no matter what you do such hardware will have issue with USB audio playback as well.

This is especially true for UAC2. If you have those issues, you need to first make sure it’s RME’s fault—I would say most time it’s not. Try plugging in some other UAC2 device and see if the problem persists, before reaching to the conclusion too soon.

As I said, as long as you are using raspberry pi before version 4, you will definitely get drop outs from USB. There is just no way to fix it.

On clean installation, with an idle system. Try playing with recent versions of MPD with alsa plug-in.  If that has drop outs, something is wrong. It should play bit perfect up to 768khz without hiccups.

Oh make sure you use a fast SD card as well.

Also try other UAC2 device and see if you have same problem with same system setups.

What audio player app are you using?