I never heard the Cambridge Audio amp, but I did buy a well reviewed Cambridge Audio D500SE CD player. I "burned it in" but it never sounded right. The bass was bloated and loose and my 8+ year old JVC CD player sounded better. I returned the Cambridge.
When I got the M3s for my living room, I picked up a Technics SADX940, a 5 channel (5x100 watts) receiver for a song at Fry's for under $150 and a Velodyne CT80 sub. I just wanted a stop gap receiver. I had a 'big' system in my bedroom - Infinity Composition Overture 3 tower speakers (almost $3000 for the pair) Velodyne CT100 10" sub, Harman Kardon AVR65 receiver, Panasonic RP56 DVD player, and other speakers for home theater. Bottom line, the M3s and Technics sounded better than the upstairs system in stereo mode!
The Technics SADX series has been discontinued and I believe the top of the line 1070 can be had at extreme discount. If you could get something like that for about $200 USD or less, I'd grab it. They work well with M3s, I suppose they'd match up well with the M22s as well.
A tube alternative is a pair of Antique Sound Labs Wave 8 monoblocks, $200 USD for the pair ($238 with a cover). They've been well reviewed and I believe they put out 10 or 15 watts per channel.
You may be able to do better by picking up some used equipment. Many audio folks are a bit crazy and constantly upgrade their systems, making some really nice equipment available at good prices.
Good luck. Choose carefully. Enjoy the music.
