Can someone school me on Bias Taps?

[rockgod212]

ok that would be great. go to weber speakers and it is in the channel/ opto switching section and the channel switch relay im using is the one with 4 low power 4 independent kit and there are 3 pics of it on there.

the circuit its going in is the metro amp i built to the afd specs. 1959 switched to 2203 and then switched to the afd/caswell boost. i also have another gain stage switched at the imput jack, so it is common to all 3 modes.

i also have the 3 or 4 dpdt footswitches for the floor box that i need to wire up with the led's (what resistor and or diode do i need for this) and i was hoping to use stereo jacks so i only have to run 2 stereo cords back to the amp instead of running 4. but if i have to run 4 thats ok too.