Sonos Connect generating buzz

  • 28 September 2019
  • 3 replies

I have 4 "Connect/amplifier" driven zones. Each zone driven by a Sonos Connect. Three zones are a traditional 'connect to amp, amp to speakers' set up.
One zone is a 'connect directly to self-powered speakers' zone.
Two of the zones have a bad buzz in one side of the audio.
The sel-powered connect routing is:
Connect RCA outputs to Audio punch block. Audio Punch block to Adam A5x self powered speaker.
Adam speaker has both XLR and RCA inputs.
Buzz is apparent on both connectors.
I've plugged the connect directly into the speakers with a short RCA cable. Buzz is present.
I've plugged the connect directly into the speaker with a short RCA to XLR cable (ground and shield tied together). Buzz is present.
I've plugged the connect directly into a Rane 'Balance Budy' on RCA inputs, and taken the transformer balanced outputs to the speaker on XLR. Buzz is present.
I've plugged the connect directly into a new, known working Adam Audio A5x speaker. Buzz is present.
I've plugged the connect directly into a known working Genelec 8020A. Buzz is still present.
At this point, I have to believe the buzz is being generated by the connect.
I have the same type of buzz showing up in a second zone.
Second zone is powered by an amplifier.
Connect is patched directly to the amplifier. Amplifier drives speaker lines to two Polk RCi80 speakers. Buzz is present.
I switch amp channels. Buzz is still present.
I switch to a known, clean amp channel. Buzz follows the connect, not the amp channel.
In short, I have a system with 4 connects, and two Play5's. There is no buzz from the Play 5's. There is no buzz from TWO of the connects. There is a buzz coming from two connects no matter what speaker OR amp channel I plug them into.
I'm 100% confident the buzz is coming from the two suspect connect units. In fact, I can repro this on the bench by plugging the connect directly into powered speakers. Buzz. I unplug the connect, and plug my iPhone directly into the speakers. No buzz. I plug the speakers into a Denon AVR line output. No buzz. I plug the connect back in to the speaker, buzz is present.
Since we've already tried balancing up the signal and sending it out (did not work), does anybody have any other buzz elimination tips for the connect? I did find this gem:

that describes grounding the digital output ground to the system earth, and i'll try that. Short of that, do I just need to replace the two bad Connect units? Is this a known issue? Seems really strange that this whole system is dead silent, but two connect units are noisy. Seems like a fairly high fail rate. The units are less than 2 years old, and the customer has been fighting the buzz since it was installed.

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3 replies

Did you swap a 'buzzy' Connect for a 'non-buzzy' one? If so did the fault follow the 'buzzy' one? That would at least confirm that the issue lay in the Connect.

Certainly tying the Connect down to an independent ground is worth trying. It's obviously not earthed via the mains connection.
Yes. I've put the 'buzzy' unit(s) on a known, clean feed to a set of speakers. Buzz follows each suspect unit.
Replace the 'buzzy' unit with a 'clean' unit, buzz goes away.
I can repro this with the infrastructure wire AND with them on the bench plugged into powered speakers. Buzz always follows the two suspect units.
Haven't made it over to ground the units to earth yet, but will report after I can make that happen.
That certainly suggests a potential hardware issue with the speaker, and not much that could be done here in the community about that. I'd recommend that you contact Sonos Support directly to discuss it.

I suggest the phone folks, they have more tools available because they're on the phone with you, but they are only available Monday through Friday during business hours.