RCA 9289 tube amplifiers

Without a doubt check them, replace needed 'out of spec' resistors, caps, ...

I would NOT go for 'upgraded, tighter, better' resistors, caps, just stay within original performasnce specs as shown of the OEM parts list.

A particular owner could chose to 'upgrade' for themselves, but you don't want to change the magic sound the original 'in-spec' parts provided.

Dad always favored rebuilding them with Sprague Orange Drop coupling capacitors.  The large can caps generally are OK.  There's no reason to change out the resistors; that's a personal choice, not an engneering choice. 

And Jasonbourne52, this is a mono amp.  I'll take some images next time I'm at teh storage space. 

Dad always favored rebuilding them with Sprague Orange Drop coupling capacitors.

That is because back in those days they were the only game in town. A lot has changed since then! There is no way I'd use orange drops for any kind of rebuild or repair at this point- they are simply outdated.

If you are selling a set of these amps I would leave them bone stock, don't do anything to them and let the buyer worry about that. Anything you do to them can damage the collector value, even though they may barely work because the filter capactors are shot.

OTOH if you do replace filter caps, the only way to do it is to do it so well that no-one can argue with the parts choice and workmanship.

i agree w Ralph unless you have a significant non refundable deposit from a client making the individual component selections....

please do keep us apprised of how this all turns out..

@hilde45  there is your Orange drop answer, i may....have dated myself....

@tomic601 Thanks. I don't know how many "orange caps" there are out there. I'm replacing mine with Mundorfs and if it goes south, I'll change them back.