Best Sonos ZP-80 Mod?

Tboooe,
Both of those questions should be posed to Joseph Chow. I don't know the answer to either one. As a beta tester, I comment to him about sound quality, reliability, and ease of use. When he is satisfied with the power supply, he will upgrade my units to the final version, except for cosmetics. At that point we will find a mutually agreeable price. I have tested his designs for a few years now.
I know that he is testing them in his system as well as in mine. I have not heard the results in his system. He did tell me his target is to stay below $300 per ZP80.

I know that Joseph Chow (Audio Horizons) has developed a ZP80 power supply upgrade which I am beta testing. It delivers a significant improvement to the music. My reference for comparison was a Levinson 37 transport which had been upgraded. When Sonos performance matched it, I sold the Levinson.
I use FLAC files from a network storage device, and play through the ZP80 digital output to an Audio Horizons tube DAC.
In order to get the best signal, both the transmitting and receiving ZP80 power supplies should be upgraded.

Barrelchief,
Yes, the sound improvement is evident from both the analogue and digital outputs. Since I listen to the digital output through a superior DAC, that signal is better, of course. For casual listening (i.e., while I'm working busy the house), I use the analogue outputs. Before the power supply upgrade, I avoided the analogue outputs because the sound quality was unsatisfactory.

Mrjstark,

From direct experience, sustained now over four+ months, I know that improving the Sonos ZP80 power supply does improve significantly the quality of both the analog and digital output signal. No doubt the Sonos clock and jitter can be improved, too. But, as evidenced every time I turn on my system, power supply is also a path to improvement

Played from the digital output through a high quality DAC, my Sonos system has attained the threshold you describe: "a SONOS interface, ease of use and sound quality that is on par with my CDP, listenable and without edginess usualy associated with DIGITAL DONE WRONG ..."

Life is good at my house. I hope Joseph Chow (Audio Horizons) gets around to offering this product for sale.