vintageHIWATTconvention.com

I have so many questions to ask about it that I figured I might as well start a new topic!
So here goes for a couple of easy ones!

1/ Being used to drain filter caps before I even start looking in an amp, I was quite surprised to notice that my caps were almost empty voltage-wise (< 15volts) without doing anything. Is something unusual going on with my 37 year-old caps (:o) or is there a sort of safety feature in the design of Hiwatt amps which auto-drains the caps when the amp is shut off?

2/ I found out that my 2 bias trim pots each control one pair of tubes but not the ones that Dave thought they should. The left pot controls the pair of tubes on the left side and the right pot the pair on the right, not the 2 outermost tubes and the 2 innermost tubes. Is this a stock configuration?

Franz

1/ Yes, it's normal for a Hylight/HIWATT to drain the filter caps when the power is shut off.

2/ Not sure about the bias trim pots, but it seems like you would want to bias the push/pull in pairs, left pair on one trimmer, right pair on the other.

I saw your post at Metro about the filter caps. Some good info here: viewtopic.php?f=2&t=32

Thank you, Mikhail! My caps don't look as critical as the ones on the link you posted, but they are old and I thought it would be good preventive maintenance to change them. Do you agree or should I still wait for other telltale signs of impending catastrophic failure? Do you have experience with slow forming caps in a Hiwatt like mine? If so, I'm most interested in learning how you went about it.

Thanks again for chiming in.

Franz

With filter caps that old it's probably best to go ahead and replace them with some F&Ts (save the old ones for resale?)

I only know what Larry aka novosibir @ Metro has written about re-forming electrolytics - never had to do it myself.

Well, I asked Larry about this. I tried to get him to tell me what he thought and how to go about it, etc...
His answer was: No!

So I'll worry about all this if some problem should arise in the next 50 years...

The electrolytics in #1949 need replaced as well. I will let you know when I have DR201 recap kits........it will be in the next week or two!