I somewhat agree with the points in some of the other comments, XM radio sound quality is not worth going out and spending big bucks for a DAC, the source and not the conversion is probably the limiting factor. However, I have two moderately priced DAC's that I have run my Polk tuner through, an Aragon D2A2 and a Channel Island DAC-1 with the upgraded power supply. The CI is the better match. While I would not upgrade to the DAC solely for occasional XM listening, if that is one of your main sources I think the very modest price you can pick up a DAC-1 for, now that DAC-2 is on the market, make it an upgrade worth making.