Quad ESL 57 problem

[British high fidelity]

Hi guys my friend has recently bought a pair of 57s from a guy in Germany, they have been totally refurbished except the power units, and now for the issue on certain tracks wheather cd or vinyl the seems to be a quick shift in the sound from left to right as if, a balance knob was turned rapidly from left to right, this only occurs when there is a build up in the song, we have changed interconnects and also swapped out the power amp from the quad 606 to a 303 and the issue is still there, they crazy thing is at the exact same point on the cd or vinyl everytime, your views and knowledge is greatly needed please

Hifi consists of

Rega rp3
Cambridge 650p phono
Quad 606 power
Rogue audio valve pre amp
Quad ESL57s
Audiolab cd player

[Barry]

Hi guys my friend has recently bought a pair of 57s from a guy in Germany, they have been totally refurbished except the power units, and now for the issue on certain tracks wheather cd or vinyl the seems to be a quick shift in the sound from left to right as if, a balance knob was turned rapidly from left to right, this only occurs when there is a build up in the song, we have changed interconnects and also swapped out the power amp from the quad 606 to a 303 and the issue is still there, they crazy thing is at the exact same point on the cd or vinyl everytime, your views and knowledge is greatly needed please

Hifi consists of

Rega rp3
Cambridge 650p phono
Quad 606 power
Rogue audio valve pre amp
Quad ESL57s

Have you tried swapping over the speakers? Does the effect remain the same, or does it move right to left? If the latter, then the problem lies with the speaker; though I can't think for the moment what that might be.

[Ali Tait]

Clamp board?

[British high fidelity]

Clamp board?
Sorry clamp board what is that

[Barry]

Sorry clamp board what is that

They are a retro-fittable circuit fitted to the secondary side of the audio transformer, designed to prevent possible arcing and damage should the speaker be fed with a signal greater than 20V rms.

[British high fidelity]

OK can that cause this scenario

[Firebottle]

Yes but it would be a loud volume level. Does it happen when very loud?

[British high fidelity]

Well when volume is at 1o'clock so quite loud

[British high fidelity]

Also when he bought them apparently everything was replaced new except the power boxes, could this be the issue

[Ali Tait]

Does it happen when playing quietly?

As Barry said, swap the speakers to see if it pans the other way, then you know for sure it's the speakers.

[British high fidelity]

OK will ask him and report back it's funny the same tracks always lose the sound from left to right not the other way round so as you said this maybe the issue, so if the sound after swapping changes direction does that mean it's the clamp board?

[British high fidelity]

Sorry from center to left

[Ali Tait]

Not necessarily, but it proves it's the speaker and not anything else.

[British high fidelity]

Of coarse Yeah makes sense sorry for being a retard, nearly midnight here and been a long day lol

[dowser]

It might not even have the clamp boards fitted - they were not standard but aftermarket. Seems strange to refurb an ESL57 and not do the EHT units, they all break down with age - maybe they have already been swapped out previously? Photos would help. If they are the wax potted items it is quite a straightforward DIY job to refurbish them.

Richard

[British high fidelity]

OK I know he bought them from a guy in Germany, apparently he restores 57s so thought he would have modified the power boxes

[British high fidelity]

Hi gentlemen and ladies, so an update on the 57s, today we swapped the speakers over and the sound still shifts from center to left, so don't think it's a speaker power issue, any other ideas would be appreciated

[Firebottle]

Doesn't sound like a speaker problem now, I think you need to look elsewhere.

[dowser]

Does same amp combo do it with other speakers? 57s dip to pretty low impedance at higher frequencies (1 or 2 ohms I think?), but that shouldn't affect a decent amp.

[British high fidelity]

Tried with proac tablets and no issue, but that's a totally different breed of design compared to the 57s, very strange unless this is natural phenomena for quads?

[dowser]

I suspect the quads are highlighting a problem with the amp due to low impedance at higher frequencies - what are amps?

[Arkless Electronics]

Quad!

[British high fidelity]

Quad 606 and rogue pre

[Macca]

It could be a specific problem with one channel of the 606 which is activated by the ESL but not the Proacs. The ESL are a weird load. You could try connecting the speakers to the opposite amp terminals i.e left to right and right to left and see if the sound now moves centre left. That would show if the amp was the problem, or eliminate it.

[British high fidelity]

Hi macca, changed the cables to opposite terminals and the sound went from center to right, so exact same sound hifi but other way round, Really strange that it's exact point of song everytime and does it on vinyl and cd, weird

[Macca]

I think you have something dodgy with that channel of the amp then. Next stage - try a different power amp.

I'm guessing that point in the track is where something fairly momentous happens sound wise? Some sort of demand is being placed on the amp and triggering the fault.

I'm not technical but I have had loads of faulty kit over the years, and logic dictates.

If it happens with a different power amp too then I'm stumped.

[Ali Tait]

Next stage - swap the interconnects from each source. This will prove it's the amp that is faulty.

[spendorman]

I have quite a bit of vintage Quad, but nothing as "modern" as a 606, surely this amp i s far more powerful than required for ESL57's, not necessarily a problem though. I remember that when the modest power 303 came out, that was even too powerful for the standard 57.

Quad brought out a mod for the 57 (extra filter for the treble unit) that had to be fitted to safely use the 303 with the 57. When the 405 came out that was provided with limiters so that it could safely be used with the 405,

As others have suggest, perhaps try a different amp, but one has to be careful, some amps object to the load of the 57, even going up in smoke.

[British high fidelity]

Hi gentlemen, we have swapped over the power amp from the 606 to a 303 and the issue is still there, also as suggested interconnects have also been changed and again no difference, very strange,

Is there any special speaker cable that is required for these speakers, and if so could general speaker cable be causing thus issue?

Thanks

[spendorman]

I just use standard lighting flex, (5 or 6 A I think) as suggested by Quad in their handbooks.

[Ali Tait]

try some different speaker cable.

[British high fidelity]

Gave my friend your advice and he wil aquire standard lighting flex and we can go from there, thanks gentleman

[spendorman]

I would be surprised if it was that, but I suppose that it's possible. Quad amps are pretty stable things. I think the 303 was quoted as being "unconditionally stable in to any load"

[Arkless Electronics]

try some different speaker cable.

That won't make any difference! Only Naim springs to mind as sometimes going haywire with the wrong speaker cable....
Of which see more below..

[Arkless Electronics]

I would be surprised if it was that, but I suppose that it's possible. Quad amps are pretty stable things. I think the 303 was quoted as being "unconditionally stable in to any load"

Many amps are. One could indeed say that ALL amps should be. I'll avoid a long technical ramble on when/how it may be OK for them not to be....
What it means is that no combination of resistance, capacitance and inductance in the load can cause the amplifier to oscillate (at an ultrasonic frequency) due to the phase shift present at the output node.

[struth]

That won't make any difference! Only Naim springs to mind as sometimes going haywire with the wrong speaker cable....
Of which see more below..

Dunno about that;)

[Arkless Electronics]

Good thing I do then :) The fact that the OP is using thin lighting flex, whilst not good for sound, will help stability.
I seem to recall early NVA power amps being rather fussy about speaker cable as well and actually blowing up, taking the bass driver with it, if the wrong cable was used....

[Ali Tait]

That won't make any difference! Only Naim springs to mind as sometimes going haywire with the wrong speaker cable....
Of which see more below..

Might be if the cable has a poor connection..

[Arkless Electronics]

Might be if the cable has a poor connection..

One would assume that the OP has checked for loose speaker connections!
I will indeed be getting the head amp off to you tomorrow as planned BTW Ali ;)