[Solved-ish] Microphone output 'breaks' when a relay is connected and powered

Got a seperate power supply, it correctly powered the relay

But it still breaks, when the lamps are on.
Starting to suspect the microphone is the wrong do'er. Gonna try with 2 arduino's in a slave master config.

You might need snubbers or diodes across the relay contacts for some loads.
What is the load. Halogen lights?
Low voltage, at what current (wattage).
Or 230volt, direct or with transformers?