Variac to power-up Beveridge OTLs?

[david yost]

Hello, All

I have a pair of Beveridge 2s that use the built in OTL tube amps. One of the speakers has a weak panel in which the mylar diaphragm is drawn into one of the stators when first powered up, due I suppose to unbalanced charges on the stators. After awhile, the diaphragm "unsticks" itself from the stator and otherwise sounds fine. Rick Beveridge tells me that this is a common problem with the older units as the diaphragms lose tension, and can be repaired by a costly panel overhaul. I was wondering if, since this is a power-up only issue, if I could use a variac to slowly bring the amp up without damaging any of the circuitry? There are discrete transistors in the driver circuit.

Thanks for any help or suggestions.

David

[latala]

I don,t think the variac is a good idea the outputs could latch to either psu rail when low !.What is required is a timer that only connects to the spk when the amplifier has settled down I am assuming this is a direct coupled device that has neither output tranformer or capacitor .It may be neccasery that the timer connects a dummy load on switch on and then after the timing period connects the loudspeaker to the amp.

regards Trevor