Voodoo Lab Amp Selector User Manual page 6

Connections
Connect the output of your guitar into Input-A of the Amp
Selector. If you are using pedal effects in front of the amplifier,
then connect from the output of your last pedal into Input-A of the
Amp Selector.
Connect Amp Outs 1, 2, 3 and 4 to the inputs of each of your
amplifiers.
Initially, set each of the Amp Selector's Ground Lift switches to the
ON‚ position.
If you are going to use two guitars (or the other channel of stereo
effects) simultaneously with different amps, you can connect the
2nd guitar into Amp Selector Input-B. If you do this, the Input-A
instrument will only access amps 1 and 2, and the Input-B instru-
ment will only access amps 3 and 4.
Power
The Amp Selector can be powered either by its internal 9V battery
or an external power source. The battery compartment is on the
bottom of the unit. Use a Phillips head screwdriver to remove the
single screw holding the battery cover in place.
The external power jack requires a regulated 9VDC power source.
The connector polarity must be center negative. The best choice to
power your Amp Selector would be with a Voodoo Lab Pedal
Power. It will also work fine with other 9VDC regulated adapters
such as the Boss PSA.
Powering the Amp Selector on and off is done via the input jack,
just like most pedal effects. Insert a cable into Input-A to power
on. Remove it to turn the power off. If you are powering the Amp
Selector with a battery, always remember to disconnect the Input-A
cable to preserve battery life.