SS Ampeg B100 power transistors - What are they?

[cjlectronics]

I'm repairing a solid state Ampeg B100 amplifier and one of the output transistors is shorted between the collector and emitter. The numbers on the T03 part is 7648 and the schematic is a homebrew ampeg part number. Does anybody know of a power transistor that I can use?

[Amp Kat]

That's most likely a manufacturor # but if it's the NPN the MJ-15025 should work and a PNP would be it's compliment MJ-15024. Make sure the emitter resistors aren't open on that blown network and the drivers for that matter.

[Enzo]

Just a thought, but if you actually include the made up part number, it will be a whole lot easier to look up. 7648 looks like a 1976 date code.

You got those backwards, KB 15024 is NPN. Also MJ15003 are common and would also work.

At this point I would HIGHLY recommend replacing ALL of the outputs, so they will match. i wouldn't count on a modern transistor sharing current well with the old ones.

[Amp Kat]

You got those backwards, KB 15024 is NPN. Also MJ15003 are common and would also work.

At this point I would HIGHLY recommend replacing ALL of the outputs, so they will match. i wouldn't count on a madren transistor sharing current well with the old ones.

Thanks Enzo, I crossed it to NTE and wrote it down as 388 instead of 68 which is it's compliment. I did exactly like you said in a DCM 600 just changing the bad one and it didn't like just one transistor and two fried so that is a great tip.

[Bernardduur]

In my unit were a TIP35A and TIP36A