The GPU being a good sound card is kinda surprising, isn't it? They (at least I can speak for the nvidia ones, I haven't tried AMD) also make an EXCELLENT timing source for VM, for example you'll be able to get much smaller buffer sizes with the GPU as your A1 device, than most other devices - but even if you don't care about a few milliseconds of latency, they are also very stable and resilient to problems that can occur when your PC is under a heavy load.
In my experience the GPU is even better than most of the ASIO audio drivers I have used. After many comparisons an competition between cards, the victorious device was to use my second monitor, a TV using HDMI, as my A1 device in VM, and can get almost half the buffer size (awesome!!) that I can get with anything else I've tried other than a several thousand dollar RME pro audio card using its native ASIO driver. It's at 160, and with my new PC I have a strong suspicion I'd be able to drop it to the minimum available buffer size of 128.
Who'd have guessed?!
I also tried the modded realtek drivers in the hope of getting the multichannel to work and had little luck with it. I did also find one that worked with MME drivers but the latency was very very high and also I found them to be somewhat unreliable after a longe period of time.
So glad to hear you got it working, that's a nice amp! Enjoy
), one-by-one testing the components, so that you could isolate the cause of the fault, and once you knew where the problem lay, you could easily solve it. That's the right way to fix any computer problem, right there!