Have Quad ESLs had their day?

[chartz]

The OTA (slight) treble lift suits me because of my own treble (slight) loss.
Jazz cymbals and hi-hats sound very close to what I hear on a real drumset in the same room!
I’ve had mine for 6 years, and they have never disappointed.

 

[Graham H]

It looks as though this chap loves 57s and Sun Ra. Unfortunately I missed the event last January, (if it ever took place), but maybe someone on here attended. Anyhow, nice photo - and anyone that listens to Sun Ra’s quadrophonic recordings using 16 stacked 57s deserves a medal IMO:

https://www.cafeoto.co.uk/events/sun-ra-quadraphonic-recordings-70s/

(Elan Carebell is head of sound at Dingwalls in London)

 

[tonerei]

As an owner of a pair that were done by that firm I can say the opposite is the case, far from being as revealing as they once were and not engaging at all. Sadly

Sorry had to read back to figure out who you were talking about. What work did you get done? The pair I had were owned previously by Rabski on Wigwam and @montesquieu . They were used by Rabski at a Scalford show with supertweeters and a subwoofer powered by Jadis monos. I had them for over 6 years and they sounded great to my ears.

If it is OTA you are referring to I would suggest going back to them and chatting about it. They are very helpful and I am sure if there is a problem they would sort you out.

 

[ian r]

Sorry had to read back to figure out who you were talking about. What work did you get done? The pair I had were owned previously by Rabski on Wigwam and @montesquieu . They were used by Rabski at a Scalford show with supertweeters and a subwoofer powered by Jadis monos. I had them for over 6 years and they sounded great to my ears.

If it is OTA you are referring to I would suggest going back to them and chatting about it. They are very helpful and I am sure if there is a problem they would sort you out.

Thanks for your concern, ( without naming or agreeing as to the firm, it's hard enough making a living these day's) I did take it up and they unhelpfully said my amps weren't powerful enough....a very unhelpful response as I was using the same amplication before the full rebuild as afterwards (25 watt per channel valve monobloks) it left an unpleasant taste and it was some 8 years back now
Literally they have been boxed ever since....another pinkfisher who also had stands and new covers done as part of the rebuild sold his 57's off as he found them unlistenable too.

I use Maggies for now but they aren't a patch on Quads

 

[chartz]

When you say unlistenable, what do you mean?

What were the differences you and your friend heard back then that made you so disappointed?

 

[tonerei]

Just fitted the new EHT boards to my OTA63's. The old ones looked tired and one of the diodes was a bit dodgy looking. Haven't got them back up on the stands yet but with a couple of haynes manuals strategically placed 63's as well as sounding as detailed as previously have plenty of bass.

 

[misterdog]

The feet on the 63> series give a 3 degree tilt upwards, though they sound better with the centre of the panel at ear level and the 3 degree tilt removed IMO.
Though the tilt also gives better stability against toppling, which was improved by adding a 3/4Kg steel block in the base of the 28> series.

 

[tonerei]

I agree the boards were fiddly to fit and I had connected the stand and deliver stands to my other pair. Too lazy to go to the hassle of changing them
Interesting I suppose it makes perfect sense a nice chunky weight would give anything some stability. Tonight was just the hope that I would have sound and no smoke

 

[cupples]

I've just acquired a pair of slightly battered ESL57s and a 33 to run with my existing rebuilt 303. One of them seems to have a slightly lower output than the other. They are newer ESLs with IEC sockets and the protection circuitry. No arcing that I'm aware of. Where would I start with stripping them down a bit and checking them over? Is there an ESL maintenance 101 web page somewhere? They cost the princely sum of £100 so I'd rather DIY than send them away for work.

 

[brecklandboy]

I would leave the speakers powered up for 24 hours and then play some music through them to see if the output levels match. If not, then my first port of call would be to replace the E.H.T. blocks in both units. Hopefully, this will resolve the issue satisfactorily.

Quad produced an A5 size service manual for these speakers which should be available online for browsing or download.

 

[fran]

So yes, definitely leave them powered up for a day before making any judgement. If at that point you still have an imbalance, the next step is to rebuild the EHT units on both. Depending on hw handy/confident you are with a soldering iron, you can either redo the existing boards, buy replacement boards online or send your eht units off to have them redone. Cost goes up with each of those options.

I would also check that you are getting sound from each of the 3 panels (just by ear) without any odd noises that might indicate a torn panel etc.

All you ever wanted to know is in the Sheldon Stokes book
https://www.pearl-hifi.com/06_Lit_Archive/07_Misc_Downloads/QUAD_ESL-57_Rebuild-Mod.pdf

Obviously take care with both mains and high voltages etc etc.

Fran

 

[cupples]

Ok, there is definitely a channel imbalance there, so once I've finished recapping the 33 I'll have a look at the EHT units. Thanks for the link!

 

[Frizzy]

I had a pair of ota 57’s, with Berning otl amp they were sublime. Tube rolling meant a good balance easy to tune in.
Played virtually anything with blinding speed and tight tuneful bass. Only sold as new property front room too small. Preferred au naturel, no sub or supertweeter.
Slowly starting to build a mono system for back room, might be using single 57 or 63, or maybe a corner horn. I just got a Lenco rigged for mono, so on way.

 

[George J]

I had a pair of ota 57’s, with Berning otl amp they were sublime. Tube rolling meant a good balance easy to tune in.
Played virtually anything with blinding speed and tight tuneful bass. Only sold as new property front room too small. Preferred au naturel, no sub or supertweeter.
Slowly starting to build a mono system for back room, might be using single 57 or 63, or maybe a corner horn. I just got a Lenco rigged for mono, so on way.

The original ESL [57] was probably the best speaker design of the mono era, and the fact that it was also special as a stereo pair meant that it persisted in production for a long time as a mainstream even after the 63 came out much later than 1963.

But the 63 will never be the mono speaker that a 57 is because the 63 is designed as an idealised point source speaker, which does help [paradoxically] in stereo replay. The 57 has a vast and not centralised mono image, and this does not sound like a point source, which helps "muchly" in mono replay as the whole panel seems to speak much as an orchestra on a stage in front of you. In live music making the sense of precise positioning of each instrument or section of the orchestra is minimal in live concert giving, and a mono ESL [57] gives a very fine presentation of the vague positioning with lucid balances [you imagine the phenomenon in reality and it is easy to do so], and absolutely minimal colouration compared to almost any speaker [mono or stereo set] before or since.

If you want to optimise a wonderful mono replay set then an ESL 57 is a wonderful starting point to plan amplification and sources to use. A single ESL does not need a large room to create a convincing mono image though enough room behind the speaker is essential, and then you can listen at quite short range as there are no driver integration issues.

I use one ESL [57] for mono VHF/FM and I have yet to find any home music on any other system as easy to forget and just listen to music. Mainly works best on live concerts [or delayed radio relays] ...

Best wishes from George

 

[Frizzy]

Thanks for info, never actually heard a 63 so good to know 57 is way to go. Going to listen to mono vinyl and cricket.

 

[fran]

Today I finished my tidy up of my stacked 57s. Luckily the diaphragms in these were all OK, but the EHT blocks needed to be done, and the dustcovers were in terrible shape (but still sealed) all round. Then there was the dust and dirt. The hessian matting on the back grilles was falling apart, not to mention the dirt of them, so I fitted new felt to the back grilles, and also used the same black felt as the top layer for the material behind the treble panels. This left them looking pretty neat. The transformers all round had rust, so I sanded down the outside and repainted them all in a fairly close matching gunmetal grey. Even though they're not really visible, its nice to have them tidied up. I used mainly new 10kv rated silicone wire all round to replace almost all of the old stiff wiring.
Lastly, I fitted the gas discharge suppressor to protect the treble panels should they get a blast at some stage in the future.

I can see why they all say that fixing these is a different proposition to fixing the 63s. They are much more delicate to handle for sure, and of course they are much older as well. I count myself lucky that I didn't have to re-diaphragm the panels, even though I've done quite a few ESL63s. It is VERY easy to nick the dustcovers when fitting the rear grilles for example, or when stapling the felt layers behind the treble panels.

Interestingly, these two pairs have serial numbers from 1959 and 1974. But the 1959 pair have the newer audio transformers, and the 1974 pair had the older ones, with the modification board to bring it to new spec. So I have come to the conclusion that either they were fixed up at some stage (the 1974 pair had a Quad service sticker from 1985) or else they all were cobbled together from different bits of ones over the years.

Apart from the tatty dustcovers, the main problem with them was that they were dull sounding. I had reckoned that maybe the treble panels were off, but the rebuilt EHT blocks brought all that detail back, and I think the new 6um dustcovers help too. The stacking frames are simple 4x2 pao painted black, with a front facia of southern yellow pine which I think matches nicely with the bronze grilles. I wasn't able to get every dent out of the grilles but most got sorted.

 

[Dowser]

The 57s are a Labour of love compared to the 63s for sure Fran - great work! How do they sound?

 

[fran]

@Dowser - do you remember these, the bottom pair are the ones where we swapped grilles with each other, black and bronze way back?
Well, I've only had them powered up since this evening, but they sound great. Lots of detail, holographic soundstage, big image and the stacking brings more dynamic impact to the presentation, most noticeable on bass. They are a bit more "polite" than the 63s, but do imaging incredibly well. In short, they are back on song, and sounding as they should and I'm delighted with how it all turned out.

You need the room for them, and in a smaller room I think you'd be better sticking with the single pair. I can very easily just disconnect one pair if I wanted - kinda best of both worlds. I have them hooked up in series - I think I did a bit of experimenting before with parallel or series operation, but ended up with series. Its probably amp dependent.

Fixing them up requires a very tidy, ordered, deliberate/mindful way of working. They require a surprising amount of "craftmanship" to really do the job well. I should have added that all the resistors in the audio transformer/crossover had drifted way off spec, as had the pair in the EHT blocks, so I replaced all those when I was at it. I put the frames on castors so I can easily pull them out etc for positioning.

The dining room table can now be returned to domestic use!

 

[brecklandboy]

Looks like you've done a great job on your '57s, Fran. Your comments on the sonic presentation of the 'stacked' pair(s) seem to mirror my experience, although my speakers are connected in parallel.

Incidentally, what amplification are you using with your set-up ?

.

 

[fran]

I'm running an Aleph (a mini-aleph actually) with them at the moment, it puts out about 25W or so. I have yet to try them with valves, i've a couple of different amp options and I intend trying them all out over the next few weeks.