Best Sonos ZP-80 Mod?

I have both a CD player and unmodified Sonos ZP-80 connected to my preamp via digital outputs. I ripped my CD's to my hard drive in FLAC format. I set up my system where I had a CD in the player, and at the same time the same CD ready to play via the Sonos system. I played both at the same time and used the preamps remote to do quick A/B comparisons. All I can say is the results were inconclusive. Sometimes I thought the music through the CD player was a bit better (voices and strings may have sounded slightly more present and less dull); other times I couldn't hear any difference at all.

Has anyone else attempted this test? If so, what conclusions have you found? If you've modified your Sonos with Empirical or Cullen mods, what differences have you found over a stock Sonos or your transport?

Some feedbacks I have read:

http://forum.audiogon.com/cgi-bin/fr.pl?ddgtl&1204503359&openflup&9&4#9

http://www.audiocircle.com/circles/index.php?topic=42526.30

Steve N.
Empirical Audio

Steve,

How would the Pacecar compare in SQ to a Prepro that has built in streaming, like the Denon Prepro. In this case the flac files are streamed from a NAS drive directly to the Prepro. Shouldn't this have the best SQ?

I have a Sonos, and the convienience is much better than the Denon interface, so the Sonos may still be the way for me to go. But, I am curious about the SQ trade-off.

Thanks,
Darrell

I have Cullen modified ZP-80 feeding an Accustic Arts DAC MKII into a Cary SLP05 (Tube)preamp into a Bryston 14BSST (600 watts). My speakers are Aerial 10T. All cabling is Acoustic Zen. In an A/B test of modified and un-modified, my wife, a friend and I all felt that the difference is immediate and dramatic. Mod has more transparent sound, no grain and tighter bass. Cannot compare to other mods because have only heard Cullen. However, in my system, well worth the money.

For about a month already i am enjoying Sonos with Pace-Car. My device has Ultraclock inside and WBT Nextgen as SPDIF output connected through Stereovox XV2 to Chord DAC64. I must say what Pace-Car does to my system is magic.
Chord has RAM buffer with 3 settings: off, medium and large. Common rule is to use medium or large buffer, then DAC averages digital sources to some level. Even pretty expensive Chord Blu transport is usually used with medium or large buffer.
But with Pace-Car best setting by far is BUFFER OFF. Music is smooth, focused and alive. I used to think that my system produces very fine soundstage - wide and deep, good separation of instruments. Now everything is much more real, microdynamics is better.