Would that still be OK with an 8ohm 20W load resistance on the speaker channel ?

Yes. The opto input is rated 50ma max or 50 volts from the audio with a 1K resistor.
Estimate it should require appx 3 watts of audio power with the 8 ohm load resistor.

 

Yes. The opto input is rated 50ma max or 50 volts from the audio with a 1K resistor.
Estimate it should require appx 3 watts of audio power with the 8 ohm load resistor.

Great ! : some numbers to work with, thanks ...

 

Great ! : some numbers to work with, thanks ...

PCBs on order !


I can disconnect the 8ohm load if I find I don't need it, although I suspect I might....

I've turned the D1 mini the other way up, so as to get D3 (which has a 10K pullup) closer to the input.

D4 and the LED may be overkill because D4 controls the on-board LED, which I will now be able see.

 

Final Circuit .... PCBs are on their way - "2023-08-23 01:34:52 Departed from sort facility, YUEN LONG, YUEN LONG,HK"

Would be nice to get this tiny project in and working, it's been a bit of a marathon !