Quad 2905 ESL Arcing Sparks

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!