Peavey 400 MKIII SJ6357

[pontiacpete]

This amp had one of the sj6357s shorted, I replaced all four on that side with mj15003s. The amp ran well for a minute then the other side had a transistor short. My question is how bad of an idea is it to use mj15022s for all 4 on this side?

Peavey-Bass-MK-III-Schematics.pdf

[Jon Snell]

Guessing you mean one of the output transistors?
Why not fix the fault before killing more transistors.
Did you check the special diode D14? Q1, Q2, Q3, Q7, Q12 & Q13 may have been damaged when the power side went bang.
Check for fresh thermal paste and insulators.

MJ15003s are ideal as a replacement.

[g1]

From previous discussion: https://music-electronics-forum.com/...7-substitution

[pontiacpete]

Thanks for posting that link, I was looking at that. I’m just wondering if there’s anything to worry about when using 15003s on one side and 15022s on the other side of the output circuit. It’s been working fine for about an hour.