I am a huge fan of passive preamps but in this case I feel you would be best served not to make that trade, and I am not a big fan of Audio Research equipment. I am assuming by the price you mentioned that this is the Serious Stereo series type model (not the ladder type), but regardless both are pretty far down my list of passive preamps that I have listened to over the years. I would say based on a cursory look at the specs for your amp a passive preamp would match up nicely (you do have to consider the source in the equation as well) and you should consider trying one, just not this one.
