I haven't wired up the pot yet. I found that by cutting the wires to the pot, it still had the lowest level. Not a problem with a hand mic, but it would feed back with my rack gear. There is a socket on the 959 board where the talk back control would plug in. On the 936, there is a jumper in place of the socket that keeps the talk back enabled. just pull the jumper to disable it. The dead key is set with the AM power pot, so I am thinking that the talk back pot could connect there, but I have not done it yet.