Take a look at the Ars Sonum Filarmonia integrated. This is what Merlin would recommend. Also consider Manley, Blue Circle, or VAC.
Depending on Merlin model, room size, listening volumes, etc. - you may want to audition some SET amps. On paper, it looks marginal, but my VSM SEs sounded great with Cary 300B monos. Vocal reproduction and dynamics! were amazing. Overall warm, but rolled off bass. A Krell KSA 50s (unsurprisingly) punched up the deepest bass but lost some of the SET sparkle. At present, a Dyna Stereo 70 provides very good reults with the speakers backed up a bit toward the wall behind them.
If you can audition in your room, try a bunch of different amps. Moving the speakers toward/away from the rear wall reinforcement will yield many possible combos of warmth vs. bottom end extension vs. max imaging vs. dynamics, etc. Depending on your temperment, you'll find this process either fun, rewarding and educational or a hellish pain in the ass.
Good luck and happy listening!
Talk to Bobby on the phone and describe what you're trying to accomplish. There are certainly many threads on this already if you'd rather wade through it. Many here have Joule Electra VZN80 stereo, VZN100 mono's (I do), VZN160 mono's, and the Berning ZH270 which all match well with the VSM's. If you must have solid state try Ayre.
Jay, I appreciate that you are asking about which amp to use but besides that, you really should send your speakers for the "MM" and Super Bam upgrade. I just got my SE speakers back and the improvement is astounding. They are head and shoulders better than the SE.
With that said, I have the Joule VZN80 amp and just got a Joule LAP150 pre. Very pleased. If an OTL like that is not practical for you then the Berning is also very good. I haven't heard the ARS integrated but I'm sure it's worth a listen.
If you have $20K, then I would strongly suggest you upgrade the speakers to current MM status with SuperBAM. Significant improvement in the BAM alone. Then you would still have plenty left over for Joule or Berning or (My current favorite, but its a bit contrarian) Atma amp. Mine M-60 monoblocks sound great with a VAC pre; Bobby likes the sound of the Joule pre with the Joule amps. If you are in the northeast, feel free to drop me a line to hear the Joule and the Atma amps.
i have to agree with the people that suggested you have the speakers and bam upgraded. imho, you will get a 50 to 60% improvement in every aspect of the speaker/bam sound. then you can consider the amp and pre amp combination. the wonderful sonic qualities of my recommendations would be more audible too because the speaker system would have less of its own character.
i like the joule la or lap 150 pre and their otls, the vzn 100s. a very organic sound, superb tonality and relaxed yet specific spacial quality.
in a sligtly different vein, the cat pre and jl 2's. this is a more energetic sound but still relaxed and very spacious. you get the best of both worlds here. with the joule the wonderful otl sound and with the cat the best of the transformer coupled style. either is exceptional and i am sure would captivate you.
one more to consider is the ma 1 or 2 from atmasphere. i have heard this amp too and it is very realistic too. so now you have 3 to consider.
bobby at merlin
The Berning ZH-270 may not be everyone's cupa tea but it's neutral and remains so on whatever speaker, it was designed to be extremely reliable (Not one has failed), easy maintenance (decades on tubes, cool running), light weight (10lbs), environmentally friendly (Power smart) and accurate.
It also has a high resale value and is currently used by two well known European speaker manufacturers to design their speakers and they having 3 or 4 speakers on the current Stereophile Class A recommend components.
Bobby, Brf is right, I live in Spain. As contributing editor of Hifilive eMagazine I have had the Gran Filarmonia one month and I was very satisfied with his sonic results in my system.
The main reason of my post was I would like get some feedback from others, as I wrote in the review I have heard the standard Filarmonia (A, Se and Sxj) with your Merlins (Tsm and Vsm models) always with amazing results.
Hm... I also wrote it, if you have some time you can check the magazine.