Andrew VK3BFA wrote:
tirade 1 deleted

Rubbish. Where do you get this 25w figure from,
tirade 2 deleted

Well, you could do the math...it's easy.
I was too lazy to do the nonlinear math for the lamp.
But an experienced (good) engineer knows how to
quickly make approximations to weed out BAD ideas.
That skill is uncommon. You'd think it's obvious.
And the GOOD engineers do it instinctively.
But the other 99% just don't get it. They'll head
down the dead-end road 'till they reach the end
then bang their head on the barricade. A (good)
engineering manager shines a light on those dead-end
barricades. See, there are situations where a light
bulb can fix a problem.

When the problem is largely unspecified, a (good)
consultant requests specificity. It's easy to
ASSUME that it doesn't have tube rectifiers, but we
don't really know.
When the consequences can be BAD, and the problem
is unspecified, a (good)
consultant recommends a conservative approach.
And when the original poster merely requested clarification
on a conservative approach, it's low risk. Proposing
a higher risk option is ill advised.

A (good) teacher tries to understand the implications of
the question and keep the student out of harm's way.

I'm gonna pull some numbers outa my ass, 'cause that's
where I keep my common sense. That way, I get a new
supply every day.

The series light bulb likely works 99.99% of the time.
But doing nothing probably works 99.98% of the time.
If your estimates are different, state them. How many times
have you turned on your amp? How many times has it blowed up
because you didn't reform the caps?

At the risk of repeating myself...IF your caps NEED reforming,
it's wise to bring them up slowly with a variac. Adding the
series light bulb will make it even safer, but only if appropriately
sized and you're paying attention...there's that pesky specificity again.

If you're really interested in reforming caps, take them out
and use a variable power supply with a BIG resistor separately for each
one. Do it very slowly...but nobody really asked that...
Ya see, if you've got series caps...more pesky specificity...
a leaky one can cause the good one to fail. But nobody aked that
either. And maybe they've got equalizing bleeders that can mitigate
the problem...assuming one's not open and making the situation
worse...but nobody asked that either.

An interesting question might be, "how do you refurbish an amp that
hasn't been turned on in a while?" But nobody asked that...

Shooting from the hip, firing off the one true, onesizefitsall, solution
when you don't know the particulars and are not accountable for the
result is...
well...it's the "internet way"!

mike