input impedance


Is amplifier input impedance purely DC or does it have a capacitive and/or inductive component ?
joegio
Everything in electronics has a RLC component, but in this case since most amps terminate directly across a resistor, I would say the answer should be almost purely DC with no input. When music is playing, it is obviously not DC. Why do you ask?
I need to know for to choose the correct value for the Vandersteen crossover for A Sonic Frontiers power 2, their website states 200K but I measured 100K, as for my Cary's the stated value matched my measured value. Once again I'm confused.
Joegio. Generally, the input impedance of a piece of audio eauipment is not important, as long as it is higher than the minimum recommended load impedance of the piece of equipment feeding the signal to it. Most CD players for example have an output impedance of a few hundred ohms, and will happily drive a signal into say 5 K Ohms. This means that they will be even happier driving into 100K or 200K. In Professional Audio or Broadcasting, the rule is that you can always drive a low impedance into a high impedance, but not the other way around. Hope this helps.
even if the sonic amps' input impedence is 100k-ohms, yule be all right if the x-overs' output impedence is 10k-ohms or less. conwentional wisdom sez 1:10 ratio is tha max ya wanna go... doug