SONOS amp contaminating power of PS audio Amp?


Ever since my last thread in the other sub-forum about S300 amp resting hiss, I started to do a little adventure on paying really close attention to noise and hiss. And today I found something quite interesting.

I have two systems sharing the same power strip (these are just normal GE power strip you buy from amazon, not audiophile). The power stripe connects a SONOS amp (the new 300w one they released recently) which powers a pair of Dynaudio speaker (let’s name it SONOS-D), and a PS Audio S300 amp which powers a pair of Paradigm speaker (let’s name it PS-P).

So here is the interesting, whenever I’m trying to switch songs in the SONOS app, the Paradigm speaker (PS-P)'s tweeter will have static hiss for 2-3 seconds before the song start. But the Dynaudio (SONOS-D) speaker is quiet and hiss free.

I’m very confused as how could the SONOS amp switching to play a new song causing static noise to speakers it’s not even powering?

A few other discovery

  1. The opposite is not true, meaning switching songs on the PS audio amp won’t affect the speakers the SONOS amp is powering.
  2. The static hiss has a unique pattern like zzz—zz-zz----zzz every single time, it’s the same pattern and feels like those signals you hear from telephone calls back then.
  3. The static noise exists even though the gains of these two amps are set to 0.
  4. The volume of the static noise does not change

As the SONOS amp uses AirPlay 2 to interact with my apps, would it possible this is AirPlay interfering with the tweeter?

So now it’s possible that the noise issue you blamed on the S300 is related to the Sonos amp or the power strip or both. Don’t you think two different systems deserve more than one shared less than $25 power strip. Chances are great that all of the outlets in that power strip are daisy chained.

I guess it’s certainly possible so I’d have to learn more. Anyway, I’m going to try out some new power strips to debug this issue. I guess there is certainly a learning curve as well as new expectations in power amps relative to, say, the usual digital gadgets you buy.

The metal-boxed TrippLite power strips are my go-to. They’re well-constructed with very grippy outlets. You’ll pay more but they aren’t too dear.

I am thinking it may the wireless switching that is making the noise.
See if there is a way to put the two systems on separate circuits. If the noise still persists you may have to physically separate the components or shield them from each other with copper foil or similar