Preamp recommendations for Quad IIs with ESL-57s

Well Quad did make a 33 and a 44 and I am sure one of those could be adapted to fit the older amps especially if you want to retain the Quad house sound. 

Hi Fi World magazine in the UK had an excellent tube preamp they sold under the name World HiFi some years back. I'd try to find one of those! They were very reasonably priced! My other recommendation is to get a Croft tube preamp. They are also UK-made!

@scrumpymanjack has this Quad preamp of yours been refurbished since new? If not, its in dire need regardless of the condition of the tubes.

You cannot spend too much money on a preamp. Really good preamps are worth it. Having said that, Stereophile had a nice test on the Topping preamp, easily shipped worldwide (on Amazon). I've never heard one, but the measurements are impressive. 

+1 “You cannot spend too much money on a preamp.”

I bought my 57s in 1973 and ran them until around 1990, when I shelved them for a pair of Crosby modded 63s. When I moved from NY to Texas in 2017, I sent the 57s to Kent McCollum for a sympathetic restoration, had Bill Thalmann restore my Quad II amps, put really good glass in them and have been very pleased with the results- I use this as a second system.

I wrote an article a couple years ago that contains some good info on assembling such a system, including amp alternatives. You can find it here.

As for preamps, I had an ARC SP 3-a-1 back in the day and certainly would have liked a Marantz 7 but both are now spendy. I located a clean McI MX110z, which is a tuner/preamp with a boatload of tubes and had Thalmann restore that as well. The McI was known as a good sounding piece and priced lower (at least at the time I bought it in 2017) than other high quality preamps. It is also "of the period."

British vintage valve equipment market is obviously different than here in the colonies. 

@scrumpymanjack has this Quad preamp of yours been refurbished since new? If not, its in dire need regardless of the condition of the tubes.

I am repeating this; I forgot to mention that if the unit has not been properly refurbished recently, the filter capacitors in the power supply could cause the power transformer to fail. I would not run the preamp until this work has been done; a power transformer for this preamp will be a difficult thing to find and likely expensive when it finally turns up.

+1 on the preamp @russ69.

Hi. 

Thanks very much to all who responded. Very grateful for the information and thoughts. Will follow up on all recommendations. @atmasphere, yes, the 22 has been refurbished.