Best Sonos ZP-80 Mod?

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.

I am very interested as well. I spent some time looking at the Cullen Circuits upgrade and it seems pretty solid though I wish it included a mod to the power supply as well.

Cedar, I wonder if the power supply from Mr. Chow can be used in conjunction with the Cullen Circuits mod? Do you mind if I ask how much the mod was?

I am very interested as well. I spent some time looking at the Cullen Circuits upgrade and it seems pretty solid though I wish it included a mod to the power supply as well.

Cedar, I wonder if the power supply from Mr. Chow can be used in conjunction with the Cullen Circuits mod? Do you mind if I ask how much the mod was?

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.

Very interesting. It is getting warmer.