Peavey CS-400 Schematics Wanted

[Barnacle]

WARNING. Peavey uses a crowbar across the speaker terminals. if the amp is blown up, ther is a good possibility the crowbar is shorted. Unless your amp is too old to have it. Th A series does not have it and the B series does. Just measure across the speaker terminals. If it is a dead short, the SAC187 triac is shorted. The little gate drive part is almost never bad. it is located on the board with the speaker posts, not up on the power amp card. So even with the power module disconnected, the short remains. The crowbar detects DC on the output line and when it does, it turns on and shorts across the output. The part usually gives its life in the process, but it keeps your speakers from catching fire.

How is model determined to have the crowbar?

I am measuring 200 ohms across both channel B speaker outputs and infinity "0" across both Channel A outputs.

All output transistors check OK.

[Barnacle]

I just got back from Florida and got back into the Peavey CS400 fix again. Before I left I took some of your advice and purchased 6 new MJ1500s Transistors and the 2 Triacs. I seem to have the wrong CS-400 schematic and board layout as it is drawn as a single board and mine has 2 seperate boards. I of course marked all the transistor locations but I have gotten myself confused on how to load all the 16 transistors back in. I have these transistors

[10 ]SJ6357
[2] 70484140
[4] SJ6344
[1] NTE60
[6] new MJ15003

But Als I do not know where the new ones go as I cannot find the proper schematic and board layout for my CS400 version.

help would be appreciated.

Originally posted by Enzo
It is designed to be a rugged and reliable power amp for live sound. Yeah, it would not be the choice for home stereo. The DDT works well, we never want clip.

Make sure none of the cement resistors are open.

The 478 can be left out for amp testing, you just won't get any DDT limiting. It is a CA3094.

The SJ numbers are house numbers. Ther are newer house numbers and then the generic equivalent.
SJ6357 = 70484140 = MJ15003
SJ6344 = 70481180 = MJ13330

You could just replace the drivers with MJ15003s as well. And since all of them are being replaced at once, you could even move up to MJ15024s all around. Just don't mix types. Even MJ15003 and 15024 have different internal contruction and won;'t share well. Pick one type and fill it up.

Peavey has a master cross reference for semiconductors, you can get it from the parts department there. Peavey will sell you parts directly and they are not unreasonable prices.

I use a lot of the MJ series power xstrs, and I buy them from Allied. Big MJs are about $2.50 each Expect close to $5 elsewhere.

WARNING. Peavey uses a crowbar across the speaker terminals. if the amp is blown up, ther is a good possibility the crowbar is shorted. Unless your amp is too old to have it. Th A series does not have it and the B series does. Just measure across the speaker terminals. If it is a dead short, the SAC187 triac is shorted. The little gate drive part is almost never bad. it is located on the board with the speaker posts, not up on the power amp card. So even with the power module disconnected, the short remains.

The crowbar detects DC on the output line and when it does, it turns on and shorts across the output. The part usually gives its life in the process, but it keeps your speakers from catching fire.

You can get parts and schematics for all Peavey stuff by contacting the parts department. Call 601-483-5365 and ask for parts or email parts@peavey.com Don't forget the cross reference, it lists all the generics for the house numbers.