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

I nor any of my friends have owned them, I have only seen/heard them long ago in shows in NYC

wiki about the speakers, several cautions about what type of amplifier

https://en.wikipedia.org/wiki/Quad_Electrostatic_Loudspeaker

excerpt

"

Its impedance is specified as ’30-15 ohm in range 40 Hz-8 kHz falling off above 8 kHz’,^[20] although another source states ’impedances are approximately 1.8 Ohms at 20 kHz but 60 Ohms at 150 Hz’,^[5] and its load is highly capacitive. It does not consume large amounts of power so much as it feeds it back to the amplifier in opposition at some points during each cycle. This is very demanding on amplifiers’ stability.^[17]

Although it is designed to be used with the QUAD II, 303, or 405 power amplifiers with limiters,^[21] a power amplifier capable of delivering 15 watts per channel suffices – excessive voltage input is known to cause arcing within the speaker panels.^[17] In fact, the instructions book states that any properly-regulated amplifier delivering no more than 33 V peak into any load is unlikely to cause damage to the speaker.^[21] Electrostatic speakers are more accurately rated by voltage, not power. In the ESL’s case, at the rated nominal impedance of 16 ohms, the limit of 33 peak volts would be reached when the amplifier’s power output reaches 15 watts (if it were driving a conventional load).^{[citation needed]}

The most common failure modes were loss of sensitivity caused by dust infiltrating the speaker panels, and internal arcing of the panels caused by excessive power to the step-up transformer;^[22] use at high altitudes may also cause the same effect.^[23] Also, because of its novel electrical characteristics, the speaker could cause some amplifiers to become unstable and could result in damage to either or both. Late in the speaker’s life, many owners found that the highly-stable 15-watt Naim NAIT launched in 1983 worked well with the ESL.^[24]"

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IF you need 16 ohm taps, that will limit your choices, my speakers are 16 ohm (but highly efficient), I tried and love this MK1 version which has 16 ohm taps (later versions 4,8 only), 22 wpc triode/45wpc ultralinear, and I found I like the sound of 6sl7 6sn7. Unfortunately, the bias adjust is internal, no bias meter. Perhaps people who have owned quads can comment if they think it would be a good pairing.

https://www.usaudiomart.com/details/650241412-cayin-a-88t-integrated-tube-amplifier-gold-lion-kt88s-nos-6sn76sl7-extras-excellent-condition/

You don’t see the version with 16 ohm taps listed often. I use mine with a tube preamp, (McIntosh mx110z) with MM Phono, and use a SUT for MC with Pass for MM. (Fidelity Research FRT-4). That SUT does not have an option that is good/ideal for the cartridge’s specs which I found in this old review

https://www.stereophile.com/content/miyajima-shilabe-phono-cartridge

"0.23mV (output) The internal impedance is listed as about 16 ohms."

You may need a MC Phono Stage with independent control of gain and impedance, FRT-4 has 4 options, but the impedance is resultant/fixed to the gain, the closest choice (30 ohm on dial) is xfactor of 18.27, the resultant impedance shown to a MM 47k input would be 141 ohms, a bit low for the formula target of 16ohms x 10 = 160 ohms.

This is why I suggest you consider a new MM cartridge now, save/check the gifted used MC, use it later when you know more and have had a chance to save for it.

The Link will show what certain people think about the 57’s and what they are able to be 60ish Years on from their launch.

Tim De Paravicini was the first to do something like this back in the early 90’s and I was quite fortunate to be able to receive a demo’ of them at an audio show during this era. I became a 57 owner shortly after, and have maintained my loyalty since.

https://www.stereophile.com/content/emia-re-visioned-quad-esl-57-loudspeakers-garrard-301-turntable-schroeder-and-schick

I know the Miyajima Labs Shilabe cartridge very very and listen to it used on a AP10 R with Glanz 12" Arm, through an All Valve Amplification System where Quad  2912 Speakers produce the End Sound, the Cart' works in a very enjoyable fashion which I suggest is never going to fatigue a person, but help find the edge of the seat on a regular occasion, there'll be no slouching back for too long.

I wonder how people think a Fisher 500C Tube Receiver (it has 16 ohm taps) would pair with OP's Quads?

I've been too lazy to take photos and list my Fisher 500c Tube Receiver for sale. I overhauled it, then had Steve Leung at VAS align it's FM Tuner. Mine is dead quiet, and has all the vintage features incl.  MM Phono, and a Tape Loop which could be used for a Chase Remote Line Controller to keep all the vintage features and get Remote Volume and Remote Balance.

I worked for Roger Modjeski for 5 years and we restored my pair of ESL 57s together. There are some things that you would need to understand before selecting the approprate amplification for the speakers. First @peter_s made a good recommendation for the Music Reference RM-10. Although the story about the amp being designed by Roger for the 57 is more myth than reality. It just so happened he owned 57s and Vandersteen 2s at the time and he originally tested the amp on the latter but then put the amp on the 57s and found it worked well with them too.

Do your speakers have the "clamp" board. This is very important to know as without it your choice of amps is going to be very limited. The ESL 57s were designed to be driven by voltage, and as mentioned previously their voltage limit is about 35V. Exceeding this limit can cause the panels to arc and eventually fail. Even with the clamp board I wouldn’t go over board with amplification, or play them too loud. These speakers if operating optimally will be full of detail, even at lower listening levels. Another note as pointed out by @pindac is that the speaker presents a capacitive load to amplifiers. Very different than the resistive loads boxes and planars present to amplifiers.

You have a unique pair of speakers. It is best to learn as much about them as possible before making an amplification decision. There are good resources out there to learn from. My advice would be to be learn before you buy.

Thank you all for your responses!

@clio09 -- I am fairly certain that my speakers have the treble unit protection from the factory. It is my understanding that that's what you mean by Clamp Board? They are SN36228 and 36260. I know that this part, as well as the ETH unit, might need to be replaced? Do you have any advice on determining when to replace, which replacement parts to use, and other parts that might need replacement? I still have not actually listened to them as I'm worried about plugging in my HK.

@elliottbnewcombjr -- I appreciate the sentiment and see your point of view swapping the whole system out. At the very least I must keep the quads, they are of sentimental value to both my friend and I. I would like to try to keep the whole thing together, but if it turns out that the tt+cart aren't great for me, what should I be looking at instead? any MCs that come to mind? Turntables? Not sure how easy it is to sell this stuff and it would pain me to downgrade. Will definitely have someone check it out and inquire as to the hours on it. I don't have a ton of specific info, but I do know that all of these things have been well taken care of (not sitting in a hot storage unit or in an attic).

@pindac -- I am very, very interested in this neurochrome route. Is the model you're referring to the Modulus 86 (65W)? Can you provide any more information on what you mean by "a increased Power Output build of a N’chrome used A/B"? Sorry for the newb question.

@peter_s -- Thank you for the rec, the rm10 also seems like a great potential option.