Manley with Harbeth Monitor 40.1

I used a BAT preamp and Manley Snapper amps with the SHL5's and it was gorgeous.  Then went to the 40.1's and it never did sound good. Maybe the added power of the 250 amps will provide more control over the bigger Harbeths. 

I've not tried Manley with my 40.1's, but can recommend Music Reference RM9 MKII, McIntosh MC275 MKV, VAC Phi 200 and VAC Renaissance amps.   All slightly different flavors, but the best all-arounder of the bunch is the Music Reference RM9 MKII.   

If you tell me what genre's of music you prefer and the sound qualities you value most, I may be able to steer you in the right direction.

Gentlemen - Thank you very much for your responses.  I would say that I have a wife variety of preferences.   Rock and roll, funk, jazz, blues, and vocals.   I may be listening to Melody Gardot one minute, Metallica the next, and Earth Wind and Fire or Tower of Power.   I want finesse with mid range magic and the ability to duplicate the lower octaves.   

I listened to a pair of 40.1's hooked up to a MacIntosh 275. The rest of the system was state of the art. The 275 struggled with the 40.1's. The left and right channels had different outputs, and there was tremendous tube rush. You need power to drive these speakers.

Regafan, in my many years of owning 40.1's with a variety of amps I have not found it to be an absolute that the speakers require high power.  I'm currently using 70 watt per channel VAC 30/70 Signature monoblocks that drive them effortlessly and I also drove them successfully for two years with a McIntosh MC275 MKV.