I have two different power amplifiers (on PCBs) and I want them to produce the same output volume. Both already have the same gain (26db) but their input impedance is different. One has 100k and other 20k.
Does adding a single 80k resistor to the line in of the 20k amplifier increase its input impedance or it has consequences to the design? I don't have its datasheet because I bought it assembled, but it's basically a Gainclone.
If the resistor doesn't solve it, what should I do to match the impedances?