I have a 12 channel amplifier, it drives a whole-house system with 5 sones. My plan was to use 5 cheap 2-channel USB-dacs to drive the thing. I tried a Muse-dac from ebay for about 30 dollars, but the problem is the noise floor, the speaker hisses somewhat when no music is playing. So this causes trouble in places like the bedroom. I wondered if anybody had a tip for a cheap, compatible USB-dac with a reasonably low noise floor?