Re: Chris Hornbeck and Patrick Turner Re: A question (6CA7 bias current)

bart wrote

> With that said, I still don't have an answer to my original
> question: Is a
> high ramp up of current draw with a return to set bias normal for
> the
> 6CA7?

It's not the kind of thing that a healthy valve can do on its own.

Does the current surge happen every time you power up, even if you
switch off and then on again after a minute or so?

Perhaps the valves have run out of electrons, or rather whatever it
is in the cathode that helps to emit them. It normally leaches to
the surface to replenish what is lost. Probably too slow a process
to explain this though.

Or perhaps they warm up quicker, before the grid bias has ramped up.
Have you tracked the grid voltage (with a high impedance meter) and
observed the phenomenon there?

Sorry if it's already sorted...I don't think I have the whole
thread. Neither am I Chris Hornbeck *or* Patrick Turner, they will
be glad to know.

cheers, Ian


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