Well, technically you don't have a pre-amp, just an integrated amp from what I could see in the manual for that model number. So if you want the "purity" of true separates, get a dedicated pre-amp. Personally I've used various pre-amps and as long as your amp works with it's output, don't see a lot of point to getting a different one, even if it is an integrated amp with a pre-out. I would assume a McIntosh pre-amp would be suitable for their amps.