2 Ports to trigger one multi-channel amp

I don’t think I’ve ever seen that issue addressed.

Personally I’d make up a simple relay board, one relay for each Port’s trigger line. Let the relays provide the 12 volt signal to the amp.

Couple 12 volt relays, a chunk of perf board and a 12 VDC wall wart power supply and you’d be good.

The PORT specs neglect giving the current capability of the 12V trigger. I’m guessing that the limit is in the 50-100mA range. If you use the relay scheme, make sure that they will operate with this current.

Another scheme would be to insert a diode in each PORT’s trigger output and tie the diode cathodes together for the amplifier. If this makes no sense to you, maybe you have a friend who could lash this up. When finished the assembly will look like a Y-Cable.

I don’t recommend simply using a standard Y-Cable unless you have input from a SONOS engineer that this is OK. 

Thinking this through makes my head hurt. haha. 

I’m surprised that so few people find themselves in the situation.  Most multi-channel amps, even amps designed for multi-room audio, only have one trigger input. 

The two issues I can think of:

1. overloading the trigger input on the amp.
2. back feeding 12v into the other Sonos.

If there is such thing as a 2 input, 1 output optocoupler, I’m sure that would be safe.  

I’m concerned about any potential issues with back feeding. It’s possible that there will not be any issues, but I’d like confirmation from SONOS engineering. Each PORT might already contain the diode that I’m inserting externally.

It never occurred to me to call Sonos.  My assumption is that they don’t have any engineers.  I assumed that in the last 5 or 10 years they have become just a marketing company, and outsource any product development. 

Maybe I’ll call and see what happens. 

~Jay

So I called Sonos.  It sounded like outsourced tech support.  After being put on a hold a few times, the support guy came back with an answer:

“What you want to do is not supported.”  

To be honest, I’m happy they tried to help.  But that leaves me back to a DIY solution which is difficult because I know very little about electronics. 

The easy solution would be to just leave the amp on 24/7.  It doesn’t draw much power when it’s idle. 

~Jay

Here’s a thread I found on another forum.  I might give it a try.  It looks pretty simple, and at least one guy had success.

https://www.avforums.com/threads/two-triggers-into-one-power-amp.2238954/

This is my diode scheme. I would replace the two ends on a Y-Cable with a new plug that incorporates the diodes. Of course I can build electronics and this scheme would be simple for me.

Not quite as slick as my approach, but these cables don’t need solder. You could use a pill bottle to house the connections. Various lengths are available. The diode can be 1N4001, 1N4002, etc. These are cheap (for a whole bag) and physically relatively robust.

Diodes should work, you’ll see about a half volt drop but that shouldn’t be an issue.

I’d lean to the relay option myself but optical isolators would work as well.

Relay: https://www.amazon.com/Bestar-Electric-BR-1050-VP-SPST-NO-Through/dp/B01N11WA86/ref=sr_1_1

Optical: https://www.amazon.com/AEDIKO-Channel-Optocoupler-Isolation-Support/dp/B095YFJ69T/ref=sr_1_17

Thanks for the suggestions!  I really appreciate it.

Why is a relay better than a diode? 

I have no problem with soldering stuff big enough to see.  I just don’t understand the finer details of resisters, diodes, transistors, and capacitors.  All I know is that they must be filled with smoke, because that’s what comes out when I break them ;) 

~Jay

Sometimes when you interconnect a bunch of audio components together some current flows in the signal lead shields that causes hum. Relays would keep these shields isolated. In your case I assume that you’ve already hooked everything up and there is no hum. Therefore, the diode scheme is no risk in this setup. If there was a hum risk, the relay scheme would eliminate that risk. The relay scheme is more work to fabricate. Besides I have a bag of 1N4004’s leftover from previous projects.

Yes, smoke makes the electronics world go round!

Couple probably minor points. Hard to read the markings on a relay wrong and put it in the circuit backwards, also unlikely to be damaged if you get the plugs in the wrong sockets.

Diodes are probably going to work fine for this.