Recommend an amp + pre for ESL 57s and a new turntable (way out of my league)

@imintohifi  Indeed. I use modified and refurbished EICO HT-35 (monoblocs) under each ’57. They are superb and respond well to good tubes.

@pindac Surprised to hear that. I tried mine on 4,8, and 16 and found 4 muffled and distorted, while 8 ohms was merely lifeless. 16 ohms is perfect. Maybe theirs were in series and yours are wired in parallel,

I hear the 57’s as a Stacked Array used at 16 Ohm when driven by a Sansui AU 111.

I never detect anything that suggests there is something quite different to my own stacked Array used at 8 Ohm.

Eico HF35’s at more than twice the power and with iron heftier than the HF81- sounds like a really good choice!

We have a number of customers using our S-30 with the old Quads.

@clio09 used to use our M-60s (a bit over-powered) with his.

No worries about what tap to use since OTLs have no output transformer. 

The advantage an OTL has is the higher impedances in the bass, which make the speaker difficult to drive with a lot of amps, do not cause appreciable loss of power. 

On this account I think is why long before I ever got into business, I had heard that Quads and OTLs were the match made in heaven. You do have to be careful with them though, as most OTLs can easily overpower the speaker.  

If the '57s are in good shape, they easily justify a good amplifier. They are quite revealing which is why the speaker is still taken quite seriously even though the design dates (and often the manufacturing dates too) to the 1950s.

The Dynaco ST35, as well as the RM-9 or RM-10 of Modjeski fame, are also excellent amps for this speaker. The older ST35s from the 1960s have 8 and 16 Ohm taps. The newer ones have 8 and 4 Ohms. 

The Sansui AU111 is a very competent amp too- if you don't mind using an integrated amp. It was so good Sansui reproduced it in the 1990s. 

@imintohifi stated "I won't contradict any of the above advice, it's all reasonable."

" Nevertheless, definitely stay away from the types of SS amps cited above, as those amps could fry."

I stand strongly be the suggestion made a Neurochrome Modulus 86 (65W) is an ideal Power Amp' for the Quads. I have a monoblock version of this on loan as I write.

@noromance stated " Surprised to hear that. I tried mine on 4,8, and 16 and found 4 muffled and distorted, while 8 ohms was merely lifeless. 16 ohms is perfect."

For me the 57's are very very likely the most commonly discussed speaker across all audio forums and are commented on as a listening experience having been driven by a huge selection of Amp's.

It is impossible to know how all experiences are able to impress, much is dependent on verbal descriptions.

My first experience of a complete rebuild of a Stacked 57 Array was using Panels 0.5dB matched with a Streamed Source and a Luxman 100 Watt Valve Amp's. I heard enough to encourage me to get on board as they were compared to a single array as well in the demo. I regret not keeping that communication ongoing because that guy was a Quad guru and totally respected by OTA, hence being able to achieve 0.5dB Panel Matching.

I have been more impressed with later listening experiences of other stacked arrays, but I am confident the source used on later experiences are also responsible for the good impressions made.

In the past few years I have been introduced to alternate designs of speaker that have been profound in how the subsequent period from a listening experience has left me doubting the 57's. I am now at a place where I am sure there is more available to my liking, from a different design of a Speaker and am almost at the point of parting with monies for a purchase.