Good Pre-Amps For McIntosh

Any suggestions for a "synergistic" combination between McIntosh MC 601 monoblocks? I have some pre-amp problems and am thinking of replacing the pre-amp.

Stick with a McIntosh pre-amp? Go with something else? Tube or solid-state? The input impedance on the 601's is 22K. Speakers are Revels Ultima Salon 2's with a pair of Rel Subs.

Thanks.

PS
If you hate McIntosh there's really no need to post. Heck, I already know that I'm an uncultured idiot who can't hear real sound and wasted my money etc. I originally wanted the Levinson 53's, but they were out of my range.