Sonos DAC

I agree with some of other posts. I personally think upgrading the power supply and possibly the output stage will give you more bang for your buck. I even want to go so far as to modify the male power input on the back to a more standard 15amp IEC so I can get a good aftermarket power cord. I use my ZP-80 with an external DAC and it sounds much better than the stock DAC in the Sonos. The Sonos can have too much sloppy bass as well as a harshness. The instruments are not very well articulated either. With my Esoteric D5 DAC, separation is much better.

you should really listen for yourself to see if you can tell the difference between FLAC, apple lossless, mp3, ogg, etc. Personally, I noticed a slight difference between mp3 and FLAC which manifested itself in a lack of soundstage and a loss of microdynamics. However, given my large music collection (5000 cds), I thought it was worth it to rip to a smaller size file (256 VBR).