I'm thinking it would be a good idea to install the presence control on my 4210.
I can see the spot where the resistor is that I'd need to replace with a pot - but I'll have to put the pot on the back as there's no space on the combo front panel.
Ricky, do I need to use shielded wire to connect to the pot?
I think you can do the presence circuit without shielded wire. I have done it from the back a few times with no added noise. Just be careful where you route your wires.