I had wondered weather the Sonos woud benefit from being attached to a DAC. I know that the Sonos does have a DAC however, there is much debate about whether it benefits from a dedicated DAC or not. The principle purpose being to reduce/eliminate jitter.
Pat, I use my Sonos system extensively and had the same question (asked in this thread
) However where I do my more critical listening I send the digital stereo signal via optical cable to my Pioneer receiver so do not use the DAC in the Sonos. However I have a friend who has listened to the Sonos with an external DAC and swears it is an improvement. My true critical listening these days is with BR audio or concert discs and I do find the Sonos inferior to that format, but then what wouldn't be?
Let me know if you decide to pursue it. Even though I did not, part of me is still curious on the subject.