SS amp for Quad 63

As my current amplifier is in for repairs I'm considering trying out some SS options for my Quad 63's.

Usual suspects like the Quad 606/909 etc seem the way to go. However I have heard some left-field suggestions like the Nakamichi 420 and Musical Fidelity P170 can sound even better . . . I like the Musical Fidelity's "dual mono" power supply and how the first 20w are class A then class A/B after that.

However I suspect that a current dumping Quad is suggested by most for a reason, however I'm slightly put off by reported reliability issues towards the end of their production.

Certainly a few nasty rumors about the newer Quad QSP's suffering from cheap parts and having constant trips back to Quad (IAG) to deal with design failings.

Any suggestions most welcome

Cheers,

Chris

I've not heard Quad 63's but recently watched a 57 owner have an absolute out of body experience when we plugged my Neurochrome 686 into them.

Divinity ensued.

Obviously, if you aren't DIY inclined you may have to see someone to put one together for you but there are a few options in the range to suit most budgets.

Worth a look.

Thanks Oliver,

I hope he had protection clamps or was listening at relatively low levels! Although I believe the scare stories of anything over 30w into the 57's are probably somewhat exaggerated.

I've made a few selectors/switches and recently soldered some 4ohm taps into an amp but this would be a leap into deep water for me. Would love to give it a go though . . .

I assume you built yours??

Quote:

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Originally Posted by Opti-cal

Thanks Oliver,

I hope he had protection clamps or was listening at relatively low levels! Although I believe the scare stories of anything over 30w into the 57's are probably somewhat exaggerated.

I've made a few selectors/switches and recently soldered some 4ohm taps into an amp but this would be a leap into deep water for me. Would love to give it a go though . . .

I assume you built yours??

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Jesus no! We've had some insane powered power amps through those 57s and they were absolutely fine. Obviously, we didn't thrash the speakers but to say the neighbours dentures were rattling wouldn't be far off true lol.

I don't profess to know very much about the ESL type speaker but if you're worried about power, there is a Modulus 86 which is less off a powerful amplifier but from all the user accounts I've read, are as stunning as the 686

I didn't build mine, no. It came built as a one off but looking at the build, it's really simple as everything is modular and Tom gives you a full manual to help with construction.

I'm sure there's folk that could help too, I would if required and our resident fix-all Mr Firebottle could be persuaded to offer advice, I'm sure.

Quote:

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Originally Posted by Bigman80

Jesus no! We've had some insane powered power amps through those 57s and they were absolutely fine. Obviously, we didn't thrash the speakers but to say the neighbours dentures were rattling wouldn't be far off true lol.

I don't profess to know very much about the ESL type speaker but if you're worried about power, there is a Modulus 86 which is less off a powerful amplifier but from all the user accounts I've read, are as stunning as the 686

I didn't build mine, no. It came built as a one off but looking at the build, it's really simple as everything is modular and Tom gives you a full manual to help with construction.

I'm sure there's folk that could help too, I would if required and our resident fix-all Mr Firebottle could be persuaded to offer advice, I'm sure.

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Alan's the one fixing my current amp . . . LOL.

Regarding the power with the 63's its fine. The more the merrier in fact. I also have freshly refurbished 57's so could be cool to try it with them too.

I'm always up for a little "out of body experience" too.

Cheers for the heads-up. Definately some thing to consider.

What's your budget for this Chris? Might help with the suggestions.

Quote:

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Originally Posted by Macca

What's your budget for this Chris? Might help with the suggestions.

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Something around the Quad 606/909 examples. Probably up to £600, something like that. Preferably less if possible but I certainly don't mind paying for quality.

I did dabble with the idea of a pair of Class D mono's from Temple Audio which is certainly still an option. As well as offerings from Baldwin Hifi. (Quad 405 clones). Anyone have much experience with them? They are revised current dumpers and look good value as components are upgraded and brand new.

He's got some cool stuff . . . Speaker/Amp switch boxes, power supplies, active/passive pre-amps etc.

https://www.reelaudio.co.uk/Shop.shtml

Try a used XTC Pow1. It will go in to low loads and has a good smooth sound. They are not too expensive. Cheaper than Musical Fidelity which would also work well.
I would expect Naim to be ok.

If it was me, I'd look for an early Quad 909, the last of the British built production. It's a good amp, will do the job perfectly and can always be re-sold later at no significant loss.

Quote:

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Originally Posted by Slawts

Try a used XTC Pow1. It will go in to low loads and has a good smooth sound. They are not too expensive. Cheaper than Musical Fidelity which would also work well.
I would expect Naim to be ok.

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Thank you Steve.

Will keep an eye out . . . kind of hen's teeth!

Quote:

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Originally Posted by walpurgis

If it was me, I'd look for an early Quad 909, the last of the British built production. It's a good amp, will do the job perfectly and can always be re-sold later at no significant loss.

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This is the general consensus. Sounds like I can't go wrong with a 909. Plus it can be "upgraded" which is always appealing (to me).

I'm thinking the synergy with the 63's will be obvious. Cheers

OK Chris here is a left field suggestion, and not shabby in the slightest. Very much cheaper too, these are new amplifiers from excess stock.

I use one of these as a stereo PA into my '57s, only bettered by Oli's Neurochrome :eek:

https://www.ebay.co.uk/itm/Proart-mo...97.m4902.l9144

If you have a suitable preamp there is a 30 second mod to bridge the controls on the front and raise SQ further.

Quote:

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Originally Posted by Firebottle

OK Chris here is a left field suggestion, and not shabby in the slightest. Very much cheaper too, these are new amplifiers from excess stock.

I use one of these as a stereo PA into my '57s, only bettered by Oli's Neurochrome :eek:

https://www.ebay.co.uk/itm/Proart-mo...97.m4902.l9144

If you have a suitable preamp there is a 30 second mod to bridge the controls on the front and raise SQ further.

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ha, did you get that working alan?

Quote:

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Originally Posted by Firebottle

OK Chris here is a left field suggestion, and not shabby in the slightest. Very much cheaper too, these are new amplifiers from excess stock.

I use one of these as a stereo PA into my '57s, only bettered by Oli's Neurochrome :eek:

https://www.ebay.co.uk/itm/Proart-mo...97.m4902.l9144

If you have a suitable preamp there is a 30 second mod to bridge the controls on the front and raise SQ further.

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Like it Alan, like the price too.

Gotta be worth a punt at that price. Look powerful enough to drive the 63's too. I have a tube pre-amp with adjustable impedance and outputs tailored for both tube and SS power amps so I'm sure I could make it work . . .

I'll be home from work this evening and likely pull the trigger.

Nice one.

I'm actually awaiting the arrival of one of those.

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Originally Posted by walpurgis

I'm actually awaiting the arrival of one of those.

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Ive still got 4 of them..lol

Quote:

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Originally Posted by walpurgis

I'm actually awaiting the arrival of one of those.

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£100 for both a bargain then??

Quote:

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Originally Posted by Opti-cal

Like it Alan, like the price too.

Gotta be worth a punt at that price. Look powerful enough to drive the 63's too. I have a tube pre-amp with adjustable impedance and outputs tailored for both tube and SS power amps so I'm sure I could make it work . . .

I'll be home from work this evening and likely pull the trigger.

Nice one.

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Yes. These are simply very good.

I can only imagine the look on my face when Alan and I sat down to try this one.

Alan's was a picture lmao.

Bargain of the century in amplifier terms.

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Originally Posted by struth

Ive still got 4 of them..lol

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Well I'm thinking cornering the Quad 306 market. :)

I would also assess using 2x 306 instead, using one channel of each amp per speaker. The 306 has a
virtual earth type psu per channel, which needless to say is a good invention of theirs, but stops you being
able to use both channels of each amp per speaker, rather one channel per speaker, gives nice advantage
for audio reproduction

If you choose the 909, you will need to spend an hour or so applying good quality heatsink compound,
(with cautions to directly touch the compound ) to assist transfer from the transistor aluminium bracket to the outer fins,

Either amp, suit passive attenuators including opto coupling and are very good sounding, and will be a excellent choice with the 63';s

Quote:

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Originally Posted by struth

ha, did you get that working alan?

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Yes Grant I did, many thanks.

Quote:

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Originally Posted by Firebottle

Yes Grant I did, many thanks.

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what was it? thought it might be a cap

Quote:

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Originally Posted by Firebottle

OK Chris here is a left field suggestion, and not shabby in the slightest. Very much cheaper too, these are new amplifiers from excess stock.

I use one of these as a stereo PA into my '57s, only bettered by Oli's Neurochrome :eek:

https://www.ebay.co.uk/itm/Proart-mo...97.m4902.l9144

If you have a suitable preamp there is a 30 second mod to bridge the controls on the front and raise SQ further.

---

Apparently these were designed and used in jukeboxes.

Gary

I would suggest either a 606 or a British built 909. The rumours are true: Chinese-built 909s now use locally sourced components, which are decidedly inferior (especially the capacitors).


Although a bit off topic, there is some misunderstanding of the maximum power to which the Quad 57s can be subjected. In the Quad instruction booklet, on page 10 it states: "Other amplifiers if they are properly regulated (not more than 33 peak volts with any load) are unlikely to cause damage to the loudspeaker, although they may not neccessarily provide the correct performance because of the very strict stability requirements."

Now assuming the Quad 57s have a nominal impedance of 10 Ohm, 33V peak voltage swing implies a peak power of 108W, or a mean power of 54W. This is usually rounded down to 50W, hence the voltage limiter which when fitted to the Quad 405 amplifier reduces the voltage swing to 20V rms, or 40W into 10 Ohm.

When the Quad 57 was first introduced, the amplifier requirements were somewhat more specific. In particular, Quad stated: "With a 30 Ohm resistive load, the amplifier should at no time be capable of producing more than 35 peak volts across the loudspeaker terminals." There is good reason for this restriction; the Quad 57 has an impedance of around 30 Ohm at low frequencies, which thus involve the bass panels of the speaker. The stator to stator distance is 3.2mm, and the bass panels are fed through a 270:1 step-up transformer. Thus 35 x 270 = 9450V, or a maximum field strength of 9.45kV/3.2mm = 2.95kV/mm. The breakdown field stength of air is around 30kV/cm, and it is this that sets the maximum voltage swing.

Thanks for the responses.

Good info there too Barry, very interesting.

Well I've pulled the trigger on the errr.... Proart's.

Couldn't resist after such a ringing endorsement. Hope you weren't all just pulling me leg!!

I'll also definitely look out for an early British 909 as they seem the "perfect" accompaniment to the 63's.

Power and control with a synergy born of design.

Will be trying these out on various speakers also just for fun.

Quote:

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Originally Posted by Opti-cal

Thanks for the responses.

Good info there too Barry, very interesting.

Well I've pulled the trigger on the errr.... Proart's.

Couldn't resist after such a ringing endorsement. Hope you weren't all just pulling me leg!!
M
I'll also definitely look out for an early British 909 as they seem the "perfect" accompaniment to the 63's.

Power and control with a synergy born of design.

Will be trying these out on various speakers also just for fun.

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I've bought a pair too!

Gary

The guy will be wondering what happened lol.

They are surprising. Just wait and see.

Quote:

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Originally Posted by Bigman80

They are surprising. Just wait and see.

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Indeed.. Good amps. Proart make some expensive gear

Quote:

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Originally Posted by struth

Indeed.. Good amps. Proart make some expensive gear

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Are you Quad-amping Grant or just a bit lonely?! :eyebrows:

Glad I'm in good company though in this cheap as chips jukebox reject wholesale boat....

We must have 1000w between us!

Quote:

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Originally Posted by Opti-cal

Are you Quad-amping Grant or just a bit lonely?! :eyebrows:

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Lol. Mono block them in my situation and have 2 in reserve now. Cheap enough to keep 2 and don't take up a huge amount of room. They are quite heavy. I have them wide open and use the quad amp as a pre.
Works well

Quote:

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Originally Posted by struth

Lol. Mono block them in my situation and have 2 in reserve now. Cheap enough to keep 2 and don't take up a huge amount of room. They are quite heavy. I have them wide open and use the quad amp as a pre.
Works well

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Nice, I will be trying a few different pre's to see what matches best.

I too stockpile when I find something worth worrying about. Often to the bewilderment of my son's mother....

Like you say though, easy enough to stash these.

Quote:

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Originally Posted by Opti-cal

Nice, I will be trying a few different pre's to see what matches best.

I too stockpile when I find something worth worrying about. Often to the bewilderment of my son's mother....

Like you say though, easy enough to stash these.

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I found if speakers like a lot of current running 1 in stereo mode works best

Quote:

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Originally Posted by Opti-cal

Something around the Quad 606/909 examples. Probably up to £600, something like that. Preferably less if possible but I certainly don't mind paying for quality.

I did dabble with the idea of a pair of Class D mono's from Temple Audio which is certainly still an option. As well as offerings from Baldwin Hifi. (Quad 405 clones). Anyone have much experience with them? They are revised current dumpers and look good value as components are upgraded and brand new.

He's got some cool stuff . . . Speaker/Amp switch boxes, power supplies, active/passive pre-amps etc.

https://www.reelaudio.co.uk/Shop.shtml

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I have the Baldwin 405 clone and most happy with it. Very well built and sq is up there. Had them for a few years now and they never fail with whatever speaker I throw at them. Not tried 57s or 63s though.

I see you are sorted with the Proarts now.

Quote:

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Originally Posted by Edward

I have the Baldwin 405 clone and most happy with it. Very well built and sq is up there. Had them for a few years now and they never fail with whatever speaker I throw at them. Not tried 57s or 63s though.

I see you are sorted with the Proarts now.

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Thanks Edward,

that's good to know and judging by last count it wouldn't be too much of a surprise if a couple more of these recommendations winged their way into my hall of amps!

The Baldwin's always interested me as they deliver good watts using a quad circuit and look rock bloomin solid to boot.

Great stuff, cheers.

Pity you are not round the corner Chris as you could have borrowed the 405c.

I also have Paul Baldwin's speaker/amp switch thing. Relay controlled and works brilliantly. Valve amp friendly. In fact I was the one that ask Paul to build it, since then he has sold many.

Quote:

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Originally Posted by Edward

Pity you are not round the corner Chris as you could have borrowed the 405c.

I also have Paul Baldwin's speaker/amp switch thing. Relay controlled and works brilliantly. Valve amp friendly. In fact I was the one that ask Paul to build it, since then he has sold many.

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Yes I was looking at that and marvelling at it to be honest. Looks an incredibly well thought out and engineered piece of kit.

Thanks that's a really kind offer. I'm in London from time to time so one day would really appreciate a listen if you wouldn't mind.

The ability to swap amps and speakers using something that well made dedicated to that precise task would save a lot of time for me!

I used a serviced Quad 606II with my 63s and was happy enough with it, but then bought a Primare 30.2 to match the Pre32. I kept both and alternated them for a while, but in the end the 606 went and the Primare stayed and is still there two years later.

Quote:

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Originally Posted by Barry

I would suggest either a 606 or a British built 909. The rumours are true: Chinese-built 909s now use locally sourced components, which are decidedly inferior (especially the capacitors).

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Barry, long shot but would you happen to know the run of serial numbers where they changed to Chinese production? I'm looking at a 909 on auction site with the serial: 9090851.

I presume the 909 dictates the model so it looks to be number "851" (which seems pretty early in the production run to me but I could be wrong).

I will continue to scour the internet for the answer but thought I'd ask the Fount Master all the same.

Thanks for your help.

Quote:

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Originally Posted by eisenach

I used a serviced Quad 606II with my 63s and was happy enough with it, but then bought a Primare 30.2 to match the Pre32. I kept both and alternated them for a while, but in the end the 606 went and the Primare stayed and is still there two years later.

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Bet that sounds awesome. It looks like a lovely amp and combo. XLR in too. Maybe a bit out of my reach at the moment but great suggestion. If I see one on the cheaper side that's good to know its a firm match.

Cheers

Quote:

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Originally Posted by Opti-cal

Barry, long shot but would you happen to know the run of serial numbers where they changed to Chinese production? I'm looking at a 909 on auction site with the serial: 9090851.

I presume the 909 dictates the model so it looks to be number "851" (which seems pretty early in the production run to me but I could be wrong).

I will continue to scour the internet for the answer but thought I'd ask the Fount Master all the same.

Thanks for your help.

---

Just found some replies from you in an old thread here:

https://theartofsound.net/forum/show...question/page2

Pretty much answers my question - looks like it should be a UK built version.

Cheers anyway.

So . . . having not really got on with the Pro-art amps (really in the minority there) I've gone for a used (but still new-ish with warranty) QUAD Elite QSP power amplifier.

(Really good price!!)

Able to massively increase its output quite easily down to 2 ohms, it should be a really authoritative amp for the 63's.

I'm hoping, considering the topology is the same as the 909 plus revised shielding and updated components, that it will be even better than a 909. That's my logic at least.

Arrives next week. Can't wait.

I've got a couple of pre's to try with it but they are both active tube ones. I know passives seem to work best with other Quad amps but one of them has adjustable output gain and feedback, so I'm hoping I can dial it in.

Any thoughts and suggestions most welcome.

Cheers,

Chris

What was the amp you had at the start of the discussion, the one that was being repaired?

I have a system with ESL 63s, and I’m using an Electrocompaniet ECI-2. It’s fine, impressive room filling sound (there are Gradients in there, which helps I suppose.) But it’s not good enough at the level of all the little special cues which, for me, are essential for making a recording sound like real music.

Where it is good, unsurpassed by anything I’ve ever heard, is in organ music.

I have other amps I could try - a Krell KSA50, a Radford STA25 and even the amp which was, I think, made for the ESL 63, the Quad 306. But basically these things are so heavy that I’ve been to lazy to experiment with them. And anyway, doing so would mean upsetting other systems which sound fabulous, in many ways better than the ESL one.

I have had Quad equipment with it, a 606, a 520, a 303. Certainly they’re not bad amps (especially the 303)

If the ESL 63 really is the great speaker that some people claim it is, I’ve still not found the ideal match. My room could also be a major limitation (wood floors no curtains or carpets, but I have fitted some bass traps and it doesn’t sound echoey when you talk!)

Hi Howard,

the amp that was in repair is a modified Ming Da KT88 push-pull. Delivers 55w in UL mode which for tubes is just about minimum for the 63's. That is if you want accurate transients and a good (but not great) helping of dynamics.

The speakers can sound good or adequate with a lot of amps but they have certain qualities which are only unlocked by certain amps (I feel).

Granted I have not tried all of them, or even most, but I am wholly satisfied with the presentation of them with the Ming Da. Most amps with a similar configuration will likely give the same result. KT88's do seem to flatter them the most too.

Now earlier I mentioned transients and dynamics, this is what I'm expecting more of with the QSP. Something slightly different. It is unlikely to have the full romantic mid-range that is usually only obtainable with tubed amplification (although not always). However I hope it will more than make up for that with an increased sense of soundstaging and power.

You seem to have a fine collection there, I would urge you to give some of them a try as some people prefer 303's or 405's etc. However I would be surprised if you didn't get most of what you are looking for with a 606 in good condition. From what others say its a super match with the 63's.

I think a lot has to do with source material and also room size. For example some people love the 303 with quads but for me I can hear its limitations with some of the music I play. Although I actually love the 303 with some large more efficient paper coned speakers but that's another discussion.

I am after some gradients myself (put an add in the sellers section without reply unsurprisingly!!) but I still have to use some digital EQ in my room with more bass heavy music.

So to answer your query, KT88 amplifier in push-pull configuration and give that 606 a good try.

Cheers,

Chris

Quote:

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Originally Posted by Mandryka

I have other amps I could try - a Krell KSA50, a Radford STA25

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Those are some stonking amps Howard, the Radford is just about as good as it gets for Quad ESL (57's) but likely a tad under-powered for the 63's.

I would definitely give both the Krell and especially the 606 a try though.

Let me know how it goes, I'm intrigued.

Cheers

Chris

If you do get Gradients, do try (though it may be very hard) to get the MT Crossover, or have it in mind to programme your own crossover. That's the weakness on the old gradient system, I believe they've relaunched the subwoofers for the ESL 63 and they have an improved crossover now.

If you add subs you are effectively destroying the point source image of the ESL 63s, and the result can sound splashy. That's one reason why the MT sub is better, because with patience you can delay the sub sound w.r.t. the main speakers, and so compensate for the slight difference in position in space. It sounds like it's not going to matter, but for me, it really did matter.

I also have supertweeters with them, which I also think are well worth trying (especially because you can get them on a free trial basis from Townshend) They just create the impression of more detail. People say they make listening fatiguing but I haven't found that; I don't listen for very long stretches of time anyway.

I suspect that the Krell will be very good with the ESLs. It's upstairs and the ESLs are downstairs and it weighs a ton . . . .

Quote:

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Originally Posted by Mandryka

I suspect that the Krell will be very good with the ESLs. It's upstairs and the ESLs are downstairs and it weighs a ton . . . .

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Take the 63's upstairs!

Quote:

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Originally Posted by Mandryka

If you do get Gradients, do try (though it may be very hard) to get the MT Crossover, or have it in mind to programme your own crossover. That's the weakness on the old gradient system, I believe they've relaunched the subwoofers for the ESL 63 and they have an improved crossover now.

If you add subs you are effectively destroying the point source image of the ESL 63s, and the result can sound splashy. That's one reason why the MT sub is better, because with patience you can delay the sub sound w.r.t. the main speakers, and so compensate for the slight difference in position in space. It sounds like it's not going to matter, but for me, it really did matter.

I also have supertweeters with them, which I also think are well worth trying (especially because you can get them on a free trial basis from Townshend)

I suspect that the Krell will be very good with the ESLs. It's upstairs and the ESLs are downstairs and it weighs a ton . . . .

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Indeed I have somewhat successfully managed to get a decent (not perfect) integration of subs with two small REL's working in stereo. Very lightly extending the bottom end and adding a bit of punch. As mentioned though, they are far from perfect.

The gradients with the proper x-over would no doubt be significantly better. Not heard of an updated version though, worth looking into.

I have also tried supertweeters. Not very expensive ones though, however they were more suited to electrostats apparently (ribbon type).

Tried for ages to set them up but in a similar way to how you mention the subs destroy the point source magic I found the supertweeters to do the exact same.

Unlike many, I feel little is missing from the top end from my 63's in my setup.

Cheers

Not sure if you found an amp for your Quads, or your budget but . . .
I run my 2905s from a Lyngdorf tdai3400 and they sound stunning. Digital amp (with options) but not class D. Most transparent amp I have ever owned (and that includes NVA, Plinius, Parasound JC1s and the earlier Lyngdorf 2200).
The 3400’s smaller brother would be fine for the Quads and can be had for well below two grand now used.
Welcome to come listen if needs be (Glastonbury).