| I think the way to construct the attenuator would be to have a fixed loss of 12-18dB. Gain at the power amplifier is usually plentifull. If your potentiometer (attenuator) is 10K and you have a fixed loss of 18dB (at the top of the throw) then your maximum output impedence is approximately 1k25. That should be low enough not to bother anything. It might be a good idea to hand match resistors per channel to maximize CMRR. |