I use a Nuforce Icon Mobile USB DAC/Amp for listening to music on my computer with my Grado headphones. (I also the amplifier portion for headphone listening with my iPod with high bit rate music.) I think the quality is excellent in those applications, and it only costs $99. If you have a receiver with a 'straight through' analog audio mode (one that doesn't run through a ADC/DAC) I think it would give good results in that use also.

Don