Quad 2905 ESL Arcing Sparks

Hi Folks,
I was listening to the Sirius XM internet stream and turned the gain up on Amarra SQ+ when popping occurred in my left Quad. I then saw sparks arc across the middle of the speaker. I eventually figured out that I should cut everything off and unplug the speaker. I waited for a while, I turned the speaker back on and then heard distortion coming from the speaker. Is there anything I can do?
Speaker needs service big time. Don't listen at head banging levels or dump speakers for a more dynamic one.
Thanks Ebm. I'm wondering what type of servicing this speaker may need and the standard costs that it will incur. The mistake was that the recording I was listening to was so bad that everything got turned up in order to hear it. In fact, the sound wasn't loud at all. The nature of this makes it really seem more like a surge ran through the speaker.
I seem to recall reading that the newer Quads such as yours have a protection circuit that is sacrificed to save the panels from damage in case of severe overload, and that after the circuit has engaged it needs to be replaced. Something like that. Perhaps Mobile Fidelity (the new U.S. Quad distributor) can help.
Thanks Bdp24, I didn't know that MOFI now carried Quad Audio. Yes, these protection circuits are suppose to work and in the past it has but not this time.
There's a repairman near Cleveland who may be able to do the repairs. And if they were still in warranty I'd be OK but I bought these a while ago. The Quad manual tells me to contact the dealer I bought them from, so in that case I need to call Audio Classics.
It's hell having something like this occur over the 4th of July weekend.
Thanks again.
take them to Play it Again Sams and have them contact Ken at Electrostatic solutions who may be able to help them over the phone.
Goofyfoot, Mobile Fidelity is now the U.S.A. distributor for Quad!
Sounds like a bad panel-
i owned Crosby moded ESL-63 for >20 yrs, with Entec LF20 Subs- sold quads wished i hadn't & bought 988's- traded 988/entec LF20 4 yrs ago as i live in HI with no AC & got tired of the humidity affecting the panels every few yrs & having to replace em after hearing noise, spitting, etc- got my rebuilt panels from Ken at ES solutions & had local guy who knows quads install panels-
Finally traded quads/Entec for mint pair of older Watt/Puppys with new drivers, etc. There not quads but i can rock em out & don't worry about replacing panels..
I agree Bgordonr and I've discovered that the panels are $500.00 each. I'm just hoping that it's one and not two or more. I'm still working on getting it up to the tech.
New panels every few years comes with Quad ownership, it seems. With the old 57's even more so! Mine are in storage, replaced by Eminent Technology Magnetic-Planars (like Maggies, but double sided magnets for push-pull operation, like ESL's).
Bdp24, I was told that the new Quad panels have a protective coating over the circuit board thus making them less prone to destruction.
That is great news Goofyfoot, I'll have to look into that. I already have the Quad voltage clamps which limit the input to them.
Bdp24, what are Quad voltage clamps?
Goofyfoot, the voltage clamp is just a simple electronic limiter I believe, allowing only a certain amount of, duh, voltage to pass through it, to prevent the 57's panels from arcing. There is no button etc. to reset after it has engaged, but I did hear that the clamp itself can be damaged from repeated high voltage levels, then needing to be replaced.
That's interesting and I do know that even valve amps blew up ESL's on a regular basis. So this must have been Quad's reassuring answer to a farsighted concern.
The 2905's are supposed to shut down when they detect loud volumes but my amp has always shut down first. This time, an arc occurred for a different reason than loud volume but rather high gain between the amp and app transport. I couldn't hear a poor live Grateful Dead recording via Sirius XM and so I turned the amp up to 60 and the transport gain to 20 something and ouch!
I'll bet when your amp has shut down it was because of the typical ESL brutal impedance/phase angle it presented to the amp. If I was going to get a new pair of ESL's, or amps for a pair, I'd look into the Roger Sanders stuff. His amp is made specifically for ESL's, as are his speaker cables. I heard his speakers at this years T.H.E. Show in Irvine and loved them.
It would be too much for me to part with my ASR Emitter II Exclusive version Blue amp. I'd probably choose a different pair of speakers if it came to that.
However, I need to be careful!