No sound from USB DAC

oam · 01 May 2010

Hi guys!

I have an Asus eee Box EB1501. I'd like to use my SuperPro 707 USB DAC (uses a C-Media 108 chip) to play stereo music through my amplifier.

The whole desired signal path would be:
PC->USB->SuperPro Dac->RCA->Tube Amplifier->Speakers

Problem is that even though Windows 7 detects the DAC as "USB PnP Sound device" no sound comes out from the speakers. My assumption is that Win7 thinks it's a "Speakers" device, thus it is outputting analog signal to it which is wrong. In fact, in the Playback devices configuration it says:

"Speakers
USB PnP Sound Device
Ready"

I can "configure speakers" from the context menu which is rather silly since no speakers are directly connected as it is only a DAC.

"Test" function causes the green bar to happily jump as if everything worked fine. But it doesn't.

I managed to find some C-media Vista drivers which install a control panel applet with which I can set the output to "Digital". This works, and the PC then outputs digital signal to the DAC and sound comes out. But unfortunately these drivers are bloated and worse sounding than the same setup in XP default drivers (where all this works, btw) so I rather not use them as a permanent solution. It should be working with the default "no-fuzz" USB drivers as in XP - if possible.

I'm asking does anyone know any registry hacks or utilities to configure the USB PnP sound device's output options? Somehow I should make Windows understand it is a DAC, not speakers device.

Or should I install a different driver what the Windows suggests by default?

And like I mentioned, this DAC works perfectly in a Windows XP with the stock Windows USB drivers.

Thanks in advance for any tips!!

oam · 01 May 2010

Well, should have known that right after I write all this I find the solution, or actually two :)

1. manually install the driver USB Audio driver. Then reboot. Then digital output worked right. This supports ASIO but not WASAPI output from for example foobar music player application.

2. Install the new C-Media v.7.12.8.2144 drivers from March 2010. These support both WASAPI and ASIO output.

I'm going with the first option because I think the sound is a bit clearer and punchy. Will do more testing but I'm happy now and hopefully someone finds this useful.