Amp for lightspeed attenuator? = $1000 used

I recently bought a lightspeed attenuator from the classifieds. It's very clear. However, my current amp has an input impedance of about 10K and the lightspeed recs seem much higher than that. I'm curious how much difference there is if I do what I'm supposed to.

Does anyone have recs for 2-channel (or monoblock) amps that are known to play nice with this passive? Ideally $1000 or less used.

Thanks!