Preamp input for ATC 100's???


have a pair of ATC 100's and am looking at a preamp that runs input Impedance: 100kohms- will that work with the ATC speakers=
It is a great tube preamp- the concert Fidelity CF-080lsxv2-
Am I looking at any problems or will it work fine- thanks
fluffers
Sorry, but I don't understand your post completely. Are you saying that the ATC 100s have an input impedance of 100 Kohms or are you saying that the preamp that you are considering has an input impedance of 100 Kohms?

I've never seen an active speaker with a 100 Kohm input impedance. The input impedance of the preamp is irrelevant to driving the active speakers. You need to know the worst case output impedance of the preamp. Typically, tubed preamps have rather high output impedance and so the input impedance of the load needs to be high as well.

Recall the general rule of thumb that the input impedance of the load needs to be at least 10X that of the source output impedance.
thanks bob- According to Concert Fidelity there Pre has an output of 1kohm- The ATC has an input impeance of 10k OHm- would that be fine?? thanks
Assuming the 1 Kohm output impedance of the preamp is a worst case value and not the value at 1 KHz, then that meets the 10X ratio.

The output impedance of the preamp will rise as frequency drops, so you can expect its worst case impedance to be in the bass region. That's why tube preamps tend to roll off the bass when the input impedance of the load isn't high enough.

I'd ask the manufacturer at what frequency the output impedance is being cited. Also, I see that the preamp doesn't have balanced outputs. Doesn't the ATC 100 only have balanced inputs?