I’ve been working on this for a very long long time ! And first I would like to say Special thanks to Thomas Uhd Larsen, a good close friend of mine on Facebook for helping me and making this possible 😛
Now, what is a SSR ? A “SSR” is a Solid State Relay, in audio they are used on the speaker output of an amplifier to protect the speaker if anything goes wrong with the amplifier. When an amplifier has problems or is going to blow up or has blown up, it sends FULL DC voltage AKA rail voltage to the speaker terminals VERY BAD and this will COOK your voice-coils and spew out TONS of smoke 😛 Not something you want !
Tipically in amplifiers they use “relays” but this is much better and faster 🙂
Short story of the circuit is here : https://sound-au.com/articles/mosfet-relay.htm
But mine is a bit different 😛 Pictures below ! When the led is on, the FETS are on passing audio signals! When the led is off! it’s in protect mode !