On Fri, 3 Feb 2017 21:05:19 -0000, "Benderthe.evilrobot"
wrote:


wrote in message
.. .
Why should someone replace ALL the capacitors on old Tube equipment?

It seems that some people advocate that.

I understand that the electrolytic caps contain chemicals which decay
over time, from the chemicals corroding the metal parts. So,
electrolytic caps should always be replaced. But why replace the old
paper caps coated with wax? All they are, is metal foil and paper rolled
up, and as long as the wax is sealing them to keep out moisture, why
should they become defective?

Waxed paper capacitors are notorious for moisture absorbtion and becoming
leaky.

There are plenty of other types of dry capacitors that don't last forever in
the high temperature around tubes.

I have been reading alot of websites about caps. One of them said the
wax coated ones were less leaky (for moisture), than the old plastic
coated ones. I am referring to the ones called "black beauties", that
have color code bands on them.Yet, back in the early 70's, I knew a guy
who was a retired radio-tv repairman as well as a Ham operator, and he
used to say those "black beauties" were far better than the wax ones.
(as well as the other plastic encased ones with the numbers on them
instead of the color bands).

That's conflicting info. Yet I know that all of them are paper caps.