Hi All,
can anyone help me nail down a cause for some hissing panels ( both Bass) on my 63's? I've re glued the stators which were coming adrift, checked the diaphragms, which were OK ( no splits or holes). So unless there's a bit I'm missing ? Just to clarify they hiss when turned on - no audio signal, but do still produce a hiss within the audio. I wondered if the HV lead connections were going, and if I should re-wire these ( any suggestions on a suitable off the shelf wire?). Also if there is a problem with the HV, would this make these on the whole quieter than my earlier pair?
Thanks
can anyone help me nail down a cause for some hissing panels ( both Bass) on my 63's? I've re glued the stators which were coming adrift, checked the diaphragms, which were OK ( no splits or holes). So unless there's a bit I'm missing ? Just to clarify they hiss when turned on - no audio signal, but do still produce a hiss within the audio. I wondered if the HV lead connections were going, and if I should re-wire these ( any suggestions on a suitable off the shelf wire?). Also if there is a problem with the HV, would this make these on the whole quieter than my earlier pair?
Thanks
What's your air humidity? Which glue did you use? Are the plates set all the way flat against to the support structure?
Hi thanks for the reply,
the humidity is OK ( low - I ran our dehumidifier for a day and they still hiss) and the stators were re- bonded using a fast setting two part epoxy which has a special mixing nozzle. All in all 4 panels required their stators doing, and to date only the two bass panels are producing a hiss (?!?). I also wondered if the diaphragms had been damaged by the stators touching them ( before I bought them) and if this would cause a leakage of the HV. The next question would be , if this is the case could the panels be re-treated with Licron?
Thanks again
the humidity is OK ( low - I ran our dehumidifier for a day and they still hiss) and the stators were re- bonded using a fast setting two part epoxy which has a special mixing nozzle. All in all 4 panels required their stators doing, and to date only the two bass panels are producing a hiss (?!?). I also wondered if the diaphragms had been damaged by the stators touching them ( before I bought them) and if this would cause a leakage of the HV. The next question would be , if this is the case could the panels be re-treated with Licron?
Thanks again
I'd suggest you set your speakers up tonight in a totally darkened room and sit there for 10 minutes so you eyes can adjust to the dark. You will probably be able to see a purple glow indicating the origin of the hiss. A visual inspection of that area might suggest a solution.
Yes I've had a good look in a darkened room, ( I don't use the original grilles and the dust covers are new), but can't see anything glowing, - I did when I switched them on and the stators were loose! Still thanks for your thoughts.
A couple of hints/notes: I've had a similar problem (and to some extent I still have, see below). The problems I did get rid of was caused by a cold soldering point on one of the elements. The sparking was very faint indeed but after about 30 min of pitch darkness I saw it. Another elusive hiss was caused by a grain of dust which could be blown away. In yet another case the cause of the hiss was a diagphram which has lost its tension - but that sparking was visible. (And a new diagphram cured the problem)
However, I am still having about the same problem as loudandclar44 with one of my ESL63s - an elusive hiss from time to time. Like him I can't see any sparks but when it's there it is audible though so far impossible to locate only by ear. Sometimes the spark-protection circuit kick ins but far from always. Moreover, the hissing seems to get worse when I attach the dustcover and the frontgrilles.
I have studied Quad's service manual but it only refers to visible sparks bar in one case: if the sparking occurs in the base. - but so far I haven't been able to locate any problems. On the other hand: At some point Quad made some changes to the grounding circuitry of the speaker because of problems of this kind. So far I haven't had the time to investigate this path further, but it might after all be worth it.
Quote from the service manual:
"2. AUGUST 1981
(b) Audio transformer shrouds are no longer earthed. Earthing connections which previously ran from subchassis to grilles via the audio transformer shrouds, now run direct from the subchassis to the grilles. This overcomes sparking occurring between the shroud and the transformer core strap."
I know this is of little help - though a sound from a fellow sufferer might offer a little consolation instead.
Naturally, I'd be very grateful for any hints myself.
However, I am still having about the same problem as loudandclar44 with one of my ESL63s - an elusive hiss from time to time. Like him I can't see any sparks but when it's there it is audible though so far impossible to locate only by ear. Sometimes the spark-protection circuit kick ins but far from always. Moreover, the hissing seems to get worse when I attach the dustcover and the frontgrilles.
I have studied Quad's service manual but it only refers to visible sparks bar in one case: if the sparking occurs in the base. - but so far I haven't been able to locate any problems. On the other hand: At some point Quad made some changes to the grounding circuitry of the speaker because of problems of this kind. So far I haven't had the time to investigate this path further, but it might after all be worth it.
Quote from the service manual:
"2. AUGUST 1981
(b) Audio transformer shrouds are no longer earthed. Earthing connections which previously ran from subchassis to grilles via the audio transformer shrouds, now run direct from the subchassis to the grilles. This overcomes sparking occurring between the shroud and the transformer core strap."
I know this is of little help - though a sound from a fellow sufferer might offer a little consolation instead.
Naturally, I'd be very grateful for any hints myself.
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That's interesting as I have located a transformer hum. I'll have to have a look at the grounding as these have the later Zener boards and the output is definitely down on an earlier miss matched pair. Thanks for your thoughts.
To rule out any cause besides the panel itself, unhook the amplifier from the speaker and short the input on both plates to speaker ground. If the problem persists it's the panel.
Arend-jan,
sorry, but could you be more specific? Do you mean remove the speaker leads, and take the HV signal wires ( on the stators) and connect them to the speaker connections? This is with the power on.
Thank you
sorry, but could you be more specific? Do you mean remove the speaker leads, and take the HV signal wires ( on the stators) and connect them to the speaker connections? This is with the power on.
Thank you
Hi All,
several months later and I've some news on the problem which may help all those fruitlessly searching for a visible arc on their panels.
As before these panels do hiss but had started to crackle, I was lucky enough to have a spare (used) bass panel and so replaced the 'defective' one with it. The buzz was still present. So out it came again, I split the panel carefully to see if there was any visible problems - none evident. I didn't get it, no visible arcing, no tell tale holes in the mylar ( its not a perfect diaphram but no holes), no outward signs of why or where this buzz was coming from. I gave it and the remainder of the panels a gentle hoover, then put it all back together. Still buzzing.
So it wasn't the panel, wiring then? Yep, that was the culprit, the HT was crackling away due to a poor solder joint. letting the panels discarge overnight, the connection was re made the crackling went away.
Hope this helps. Thanks for your suggestions.
several months later and I've some news on the problem which may help all those fruitlessly searching for a visible arc on their panels.
As before these panels do hiss but had started to crackle, I was lucky enough to have a spare (used) bass panel and so replaced the 'defective' one with it. The buzz was still present. So out it came again, I split the panel carefully to see if there was any visible problems - none evident. I didn't get it, no visible arcing, no tell tale holes in the mylar ( its not a perfect diaphram but no holes), no outward signs of why or where this buzz was coming from. I gave it and the remainder of the panels a gentle hoover, then put it all back together. Still buzzing.
So it wasn't the panel, wiring then? Yep, that was the culprit, the HT was crackling away due to a poor solder joint. letting the panels discarge overnight, the connection was re made the crackling went away.
Hope this helps. Thanks for your suggestions.
Me too - glad it helped! I'll have to have a closer look at mine. I read somewhere else (it may even have been in this excellent forum) that greasy fingerprints on the frames of the elements might case a slight (and invisible) arc. Luckily it is not relevant now - but I thought I'd pass the information on.
Thanks to both for the kind words. Sy - I agree - although these are used and in need of some more attention, they are excellent and can only get better.
Klaskov, thanks - I read that too, also I've read that it isn't just greasy finger prints, the diaphram coating can be transferred to the outer edges causing leakage. Somewhere I read that the mounting screws can be replaced with plastic ones which may help leakage in this area but I haven't tried this yet. What I've learned by working on these is they are more resiliant than I expected for such 'fragile' items.
Klaskov, thanks - I read that too, also I've read that it isn't just greasy finger prints, the diaphram coating can be transferred to the outer edges causing leakage. Somewhere I read that the mounting screws can be replaced with plastic ones which may help leakage in this area but I haven't tried this yet. What I've learned by working on these is they are more resiliant than I expected for such 'fragile' items.
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