Prefered Amplifiers to run with Harbeth M40.1

Here are the amps I Have used with the 40.1s. The best by quite a large margin is the
BAT REXPower amp. Most inner detail, best control of the bass, huge soundstage. Just no faults with the harbeths.
VTL MB-185 signature monoblocks. Had i not tried the BAT, these would have been here today. SUPER big and liquid midrange. Plenty of power, bass a little loose though.
Manley Snapper monoblocks. Good Sound, and lots of pop. Just could not get the soundstage to open up with these amps. They were great with the SHL5s though.
Bryston 7Bsst monoblocks. Last and all around least.

Chris,
Have you thought about trying a crossover between your pre/amp? Thats the way i am going with the new YGA speakers and my JL Audio subs. You might try a cheap one from Marchand or someone and use your REL to cover the bass. (from where ever you Xover) Fairly cheap fix (no amp changes) and you still keep the best of the Harbeths and use the REL to your advantage.

Are you ready for this? Spectral DMA 260. Transparent but in the best way. Clarity. Great amp. Loving my spectral/harbeth combo.

There's a Harbeth owner named "Denjo," who posted his extensive experience using many different amps with his speakers. The thread was here, on AA, or at the Harbeth Users Group. I think you'd find it worth your time to track it down. Good luck.

I have the same speaker . I have the pass xa 160.5 very beatyfull bass and very control mid , high and the bass . I have the bat 52se preamplifier to me it's a good match . I hope it help you