Basically, you would plug straight into the amp switcher. You come out of the amp switcher (preamp/amp send 1) to the input of the first amp and (preamp/amp send 2) to the input of the second amp. To control it, connect a standard chord(I think it can be shielded or unshielded) from the loop out on the GCX to amp switch 1 on the amp switcher(to control preamp/amp send 1 on/off) and another loop out on the GCX to amp switch 2 on the amp switcher(to control preamp/amp send 2 on/off). Once you see the back of the amp switcher it should all make sense. You won't use the returns on the amp switcher unless you plan on sending a preamp out signal from your amps back to the amp switcher. Remember, the amp switcher has no load so you always need to have a speaker or load box connected to your amps at all times.