Ampeg B115 Transistor Suggestions

[Jecarroll7]

Amp came in with all of the output transistors fried along with a half doz components.

Looks like the output section has previously been slightly modified.

The (4) original output transistors 2N4348 (per schematics) were replaced with 2N3773s

The (2) transistors driving the outputs were beefed up. Schematics call for 2N5682 (Q302) and 2N5680 (Q303) which is a TO-5 package.

However I have (2) TO-220 RCA transistors 262N9C and 262N10C instead, I haven't been able to cross reference these numbers, date codes are 1977.

Any suggestions for a TO-220 package replacement for these two? Schematic attached.

[Steve Conner]

The MJE15030 series are great driver transistors if you can get them.

Watch out for fake 2N3773s when shopping for replacement output devices, it might make more sense to use a modern device that's still in production and can be bought from a big distributor, like the MJ15003 or MJ15024.

[gbono]

The 2N3773, in its RoHS version, are still available from On Semi/Digikey. Not sure about distribution in the UK (RS Spares?)

I would suggest using the 2N3440 and 2N5416 from ST Micro for the drivers.