Ralph, this sounds like a reference to Nelson Pass.
Yes. I have very high regard for Nelson. One of the top designers today.
I tried a pr of Ma-1s into Sound lab A-3s it was abysmal, severely lacking bass, highs and had poor drive. enter the krell ksa-250 and there was all the bass you could ask for, restored highs with plenty of reserve.
A few years ago I bought my 3rd pr of Quad 57's, coincidently the seller demoed them with a pr of M60s. All of the 57's sonic hallmarks were intact and they sounded great, nothing I would specifically attribute to the amps per say. After I got them home I emailed you about using the S30 and you recommended the M60 since you didn't think the 30 would do it. I found the recommendation odd since its well known stock 57s are designed to take no more than 25 watts or risk damaging the speaker.
I've tried many of the classic 57 pairings incl the Bedini 25/25, classe dr-2, Radford STA25, Graaf Gm20 (OTL), VTL TT25 (aka tiny triodes) among others. overall I still prefer tubes driving 57s (imho, EL84-based amps sound best) there wasn't a case where tubes bettered the SS amps in the bass region. because 57s are so limited in freq extension the subtleties in bass quality are easily discernible going from tubes to SS..
The S-30 plays the ESL57 fine, but in certain installations there can be issues related to the placement in the room. In such cases I will recommend the M-60, and because the M-60 has too much power, often a speaker protection fuse is a good idea. If you have an updated version of the 57, it may have a new protection board making the fuse unnecessary. If you are getting better bass with transistors over tubes on a Quad 57 or 63, it indicates a room placement problem!
If the MA-1 was not playing bass on the Sound Lab you should have said something at the time (based on your description I am placing all of this in the 1990s; you might consider another audition as much has changed in the intervening decade and a half or more...). Even with all the iterations that have been out there, bass on a Sound Lab has been constant ! So this points to an actual malfunction somewhere. We did document a number of issues with Sound Labs, some of which appeared to be bugs and others that were actual design changes. We brought some of these to Dr West's attention, and over time the speaker got easier to drive.
Mind you, not only did the MA-1 have troubles on certain models but so did the ARC Ref300, The big Cat amplifier, the big CJs and others- we were in good company. Ultimately Roger discovered that a simulation of the crossover design actually had nothing to do with the actual impedances found in the speaker, something we had suspected for over a decade. This resulted in a new backpanel, which can retrofit on to almost any Sound Lab (A1, A3, Ultima and so on). Not only does it make it a lot easier for our amps to drive the speaker, it makes it a lot easier for transistors to drive it too and has the very nice side benefit of a better sounding speaker that for all the world seems like it is 4-5 db more efficient! So you can do with an set of MA-1s what used to take a set of MA-2s.
With that update the Sound Lab has taken its place as one of the top speakers made, price no object. It is certainly the state of the art in ESLs, perhaps in planar speakers in general. They have no issues with dynamics, something that has always troubled ESLs, no need for a subwoofer and can be driven in most rooms with no apparent limit of power using a 200 watt amp. Sure, its not as efficient as a horn, but you don't need 600 watts to make it fly. In most rooms with our MA-2s you can't clip the amp. That's a big change from where that speaker was only a couple of years ago. They are big, they are impressively musical and there was nothing like them 25 years ago.
