BEAR wrote:

: Kind of irrelevant - these are not exotic transformers at all.
: If you know the turns ratio, the primary inductance, and the freq
: response of a good one, you know everything you need to know to replace it.

: The HV xfmrs are generic anyhow.


Would agree on the hv one, not so sure about the one on the audio side. I
know even in the late 80's it's wasn't too expensive nor difficult to get
transformers custom made, in short quanities (100-499 peices). These days
they barely use them in power supplies anymore let alone audio applications.

Anyway, decided to take a shot at it, pulled them out of storage and got the
brain-boxes off. One observation to make, especially after reading your post
about the ESL's, could be the HV board after all, at least the previous
repairs.

Looking closely at them now, what I thought 10/15 years ago when examined
after one of the repairs, it does give the illusion the audio transformer
was replaced because of the extra rtv glop around the terminals. But I think
now it's just extra rtv.

The way he built these, the box is just a simple aluminum u-channel with
everything, the two transformers, the two "circuit boards" (in quotes
because they are hand-wired, no copper traces) attached via rivets and
eyelets. Looking at the rivets, it appears the only ones replaced were the
ones attached to the hv board. The ones on the legs of both transformers all
seem to match, including the same dull color.

So maybe it is just a bad diode or cap on the board.

The other panel is playing fine so going back and forth to figure out the
differences with one to the other will sort of be a peice of cake. Is no
problem running them with the covers off and mounted on the panel.

Need to go grab my test gear, if nobody is too bored with the subject will
report the results in a few days. Might as well take a few pictures and draw
out a schematic, will post those somewhere in case it does some good in the
future for someone else.

thanks,

-bruce