I'm building up a midi controlled DPDT relay which allows me to bypass my guitar effects. Everything works fine. The relay is isolated with the current drawn to ground by a 2n3904. However, I'm getting this ticking noise each time midi data is received. I'm pretty sure it's Midi interference that's leaking into my audio signal but I cant find what's the issue. This is especially an issue when I send a stream of Midi CC messages into the looper.
The problem still occurs when I remove the 6N138 opto isolator, and even with the microcontroller removed.
Any ideas?
The problem still occurs when I remove the 6N138 opto isolator, and even with the microcontroller removed.
Any ideas?