Sonos DAC

There are at least two ways to improve the Sonos performance. Here I am referring to the ZP80, which has both digital and analog outputs.

I have seen an advertisement on Audiogon to upgrade the digital signal processing of the ZP80. I recall that the upgrade costs about $550. It ought to improve signal processing from both the digital and the analog output. I have not listened to any unit with this upgrade.

The second way to improve the ZP80 is to upgrade the power supply. I have listened to units upgraded in this way. It does significantly improve the quality of the output signal, adding weight to lower frequencies, while diminishing glare and improving articulation at higher frequencies. I use an external Audio Horizons tube DAC for attentive listening sessions. While I'm working around the house, I use the ZP80 analog outputs. I'm very pleased with the quality of the signal.

The power supply upgrade is not marketed yet - I am a Beta tester. It will be sold by Audio Horizons pretty soon, I guess. The cost should be about half as much as the digital signal processing upgrade mentioned above.

If I choose to use an external DAC should I opt for traditional digital input or USB?

Sonos does not support the USB output, I think. Digital coax or optical are the only choices. I prefer the digital coax.