Dear Sam
Hooray for Super Mario! You are indeed a fortunate man to have such a friend. There was only one fellow I trusted in Australia with mine, and he lives in Melbourne. Everytime I needed something done, down to Pack n Send they went in their custom shipping crates and off to the repairer they were sent. Although to be fair, once loving restored, they were good for a number of years, before they needed the panels done again. The humidity in Sydney did not assist.
I preface everything by saying I expect you have clamp boards on them, or otherwise enjoy the sight of blue sparks arcing when you over drive them ha ha. I've fried a few treble panels in my time doing exactly that. All going swimmingly then - whoosh - up a panel goes. Sparks and flames. Clamp boards after a few times of that.
I have heard them with quite a few amplifiers, although none of the class of that which you own, or have experimented with. The most expensive amplifier was a Ref 110, which was typically ARC, a Mac 275 (ripe & lush come to mind with gob-loads of power) and oddly, a Kondo Neiro, the latter being particularly ill suited (but a gorgeous amplifier). None I owned, all belonged to other audiophiles. I should own a Ref 110 in a moment, had I the space. Very competent and fine amplifier, I feel.
I tended to favour push pull designs in the tube line with 57's, and have always been fond of a lovingly restored Leak 20 or Radford, particularly when coupled with a decent tube pre. I heard a Shindo pre (the humble Aurieges) and a Leak 20 once and thought it enchanting.
In recent times I had great success with, believe it or not, a cheap Croft integrated with a rather lovely MM phono stage, which paired magically well with a Len "The Cartridgeman" MI cartridge (the cartridge was twice the cost of the amplifier - it was one he made to order - around £2000 by memory - and was a cracker - loads of detail but with life). I rolled the tubes in the amplifier to whatever it was that Mr Croft or Mr Gregory recommended (I don't know what they were now but do recall that they were some ghastly expensive NOS Mil Spec Mullard's that were almost as expensive as the amplifier).
Mr Croft uses 57's himself, so all his amps are stable into them. It wasn't an expensive system (well apart from the deck - a GPA Monaco + Triplanar VII - much underrated deck & arm combo imo and is a snip secondhand, as I bought mine) but was one of the most musically satisfying I have assembled; particularly when coupled with the generous Decca SXL recordings I favoured. Past tense in that I have since departed from vinyl shores.
If I had kept that system, I would have gone up the Croft line. I liked Mr Croft. He was direct and a decent fellow. His products seemed to combine very well with the 57's, and I feel a Croft MM pre, particularly when coupled with a MI cart, had some magic. The weren't the last word in anything, but I became immersed in the music, which is all I ask.
I tended to listen near field to them - like a giant pair of headphones - usually about 1.5m away - with frames to bring them to ear height or titled if on their original legs, with me lying down on the floor with a pillow under the head (good for the back if not for bones). Many a performance was heard that way. It had teh advantage of not requiring large volume for detail and impact.
Personally I don't think you need to spend a fortune on the amplification for 57's, although I cannot speak to a stacked pair. I like very much some of the classic amplifiers - e.g. an ARC Classic 60, or an EAR 864 or even the newer V20, the latter I look forward to hearing at some stage, but whose design certainly appeals
On the other hand, I don't think you can afford to run a poor source through 57's. They are, as you know, very transparent. Certainly I am sensitive to timbre and timing with classical music, which is why, when I was into vinyl, I favoured direct drives over most belt drives I heard. It's the decay that is so hard to get right, or so it seemed to me. But really my audiophile adventures while extensive are at a much lower level of excellence than yours, and indeed most on this forum, but have been appropriate to my means, which by any measure are modest.
I should mention I owned a pair of 2905's for a while. They were very good, but they didn't have, in my view, the magic of a single pair of 57's. I owned them together, and so could compare. I know many would say I am simply being nostalgic and of course the 2905 (really a souped up 63) was in every way a better speaker, but I thought not. Not in the mids. Not where the music is.
Admittedly I bought a dud (demo) pair of 2905's, and my 57's were the best pair I owned by some margin, so perhaps the comparison was unfair (both were driven by a Luxman 550A II). The 2905's spent more time with me carting them to and from the service agent here (who had never worked on any before and lived 3 hours way from where I lived) than I did listening to them, so it wouldn't have mattered if they had been the second coming, I had learned to hate them after a few months of wasting my Saturdays in traffic hauling around a dirty great pair of 2905's, and paying for parts to be imported from England (from China to England to Australia) and then fitted. The tech was competent, and meant well, it was not his fault he was given a manual by Quad and said - "there you go". I recall he was horrified at the lack of skill in the soldering and general construction of the 2905's (they were made in China) when he took them apart. So was I. Vowed and declared after that never to buy another Quad ESL, and don't expect to change my view on that. 57's aside.
That is the problem of course - finding good tech's in the event something goes wrong with ESL's (as it inevitably does). Hooray for Super Mario!
An interesting speaker, and one I currently own, is the Fujitsu Eclipse TD 712 II, a single driver speaker that has many of the qualities I admire in 57's, but which is domestically alot more acceptable in a shared living space. They require current to get under control, and are beastly to drive but are very fast, and of course coherent. I like them.
I will watch with great interest your adventures. I know that the ARC Ref 110 & Mac 275 had ample power for stacked pairs. Loads of current, but a very different sound, of course. I preferred the ARC, it being more accurate, but depending on source (a generous source with ARC is always rewarded I feel). I don't think you can go wrong with any of your intended choices - but you may want more current than the Lamm's can deliver up. The treble dip is a bugger to drive. But then again, with 57's, my approach has always been to suck it and see, and I suggest there is no substitute for trial and error in your space.
Cheeri Pip,
Edit: @ Folsom - I think I spotted a Pi Tracer, which is a superb transport, to my ears anyway.