RCA 9289 tube amplifiers


The RCA 9289D was the final version of this great 200W amplifier.  It features four 6550 in the output stage and an interesting power supply with OD3 regulators.  My father designed the final version of this amp for RCA and we have several available.  I'm testing the water to see if there's still a market for this excellent amp before I start recapping them, or whether folks would prefer them bone stock.

cdietze

Is this a mono amp? I'm guessing it must be fifty/sixty years old! Certainly new caps throughout would be a prudent upgrade!

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 There is no way I'd use orange drops for any kind of rebuild or repair at this point- they are simply outdated.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....