Should I also replace the driver transistors?

[Axtman]

I am working on a Peavey Mark III amplifier. Most of the original output transistors (SJ6357) are toast so I am going to replace all of them with replacement transistors (MJ15003). Should I also replace the driver transistors?

[Enzo]

I would. Any time I have to replace a shorted output transistor, I replace the driver as well. Even if it tests OK, it was stressed by the larger part. they are not expensive.

Make sure to check all associated resistors.

[olddawg]

I would. Any time I have to replace a shorted output transistor, I replace the driver as well. Even if it tests OK, it was stressed by the larger part. they are not expensive.

Make sure to check all associated resistors.

I second that option. It's standard procedure. A dollar or 2 will save you many call backs. I'm fond of replacing bias pots as well.

[Enzo]

Yes, it is no place to be cheap and "save money".

Fortunately there is no bias adjustment on these old PV amps.