My amplifier case & wire are still stuck in Memphis, TN at the FedEx hub 🙁
Anyway, I’ve noticed that the power amplifier itself doesn’t include a 12v trigger so I decided to make one.
I bought that relay but it comes with no documentation.
Apparently when I power 9v on the DC+ and DC- there’s a tiny red LED that lights up. Then if I short the IN with the DC+ another tiny green light turns on and I hear the relay.
The ohmmeter does show a change on the other side of the board so that must be how you set it up 🙂

We did not cover that in pastry school so what do I know.