Need Help With Transistor Substitution

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Hey all. I'm back on a project I had to put on hold for the past year and a half. I have a Fender Rhodes keyboard amplifier model FR7710.

I need some help selecting a substitute power transistor(s) for a RCA 2N6254 Si, NPN. I would rather not use NTE if at all possible. On Semi would be nice. I am attaching the datasheet that I have for the 2N6254. Any other info needed, please just ask. Also, if this post is in the wrong place, I apologize and please move accordingly. Thanks.
 

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  • 2n6254.pdf
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The original RCAs were those old hometaxial types - which are now unobtainium. In its time, the 2N6254 was basically a "super 2N3055". The closest thing currently available and least likely to give you grief is the 2N3773. If the faster modern version causes oscillation, usually adding a base stopper resistor will fix it. In many of the older circuits that didn't have gobs of loop gain, increased output stage speed doesn't cause any problems.
 
Boca Semiconductor Corp has them and the search said that 50000 from On Semi
are available. But you will have to ask for a price quote. Just put 2N6254 in the search
box at the link below.

Anyone says they have 2N6254's from On Semi is lying. It was an RCA part that's been out of production for decades. If you find something from Central Semi or Inchang or *ahem* NTE, it's probably some generic that's rebranded. Might pass spec, might not. Might even be a 2N3773. They die are cheap enough to rebadge or repackage, and sell as some similar unobtainium part. For $6-12.

The only 2N6254's that I would trust to actually be 6254's have short leads with solder on them, marks around the screw holes and 1970's date codes.

That being said, if you stuck pretty much any of the modern On Semi 4-ish MHz epitaxial audio output transistors in there it would probably work just fine. And if it does oscillate the fix is pretty easy.
 
Thanks for all the input. I went to OnSemi and I wrote them asking if they had a substitute/equivalent/replacement for the 2N6254. They guy who wrote me back sent a couple datasheets of possibilities. If you would, take a look at the one I'm attaching and tell me what you think. Personally, I don't think it looks bad compared to the 2N6254. Thanks.
 

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  • 2N5038-D.pdf
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  • 2n6254.pdf
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Here's a diagram of the circuit I forgot to included in my Op if it helps or matters. That 2N3773 looks good, too.
 

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