CS 8ooX schematic

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Yes, from Peavey. Call them at 601-483-5365 and go to parts. Request the schematics. Generally they email them for free. In some cases they send paper copies on 11x17 and charge a small $2.50. The drawings include parts layout and parts lists. Peavey will sell you any part in it if you can't find it on the open market. Their prices are reasonable. I buy the output devices generically from ALlied, but PV prices are not out of line.

You can also email parts@peavey.com but that usually takes longer.
I'm not sure yet, I havent dove into it totaly yet. I've been haveing a ptoblem w/ a crate pa6fx. The guy brought it to me and said it was smoking, He also said someone plugged a input into a output, (not sure what he ment by that) I opened it up and a hole section of the board was burned out. I replaced all the parts the was visibly burned out and a few others that I thought would give me problems. I had to do a hard wire for a point of the board that was bad but that came out alrigth. I then plugged it in and it started humming and smoking, I then relized I should have first checked the transistors, I found 3 bad ones ( 2 MJ15022 and 1 MJE15030 ) so I replaced them, made sure all the parts I replaced the first time (22 in all) was still good put it all back together plugged it in and turned it on, it started huming again and then blew out the fuse. now I have it all apart again. I am now thinking maybe I shouldn't of took this project on but this stubborn side of me won't say no or give up.
You need a variac or at least a current limiter - a 100 watt light bulb wired in series with the AC mains going into the amp.

And may I suggest putting the Crate amp in a separate thread from the Peavey. It can get real confusing trying to work on two things in the same thread.

When those MJ15022s were shorted and their little driver, it is pretty likely one or more of the MJ15023s on the other side are shot or at least their driver.
Thanks for your help Enzo, I tested the other side and they "seemed fine". Here is the schematic for the main board, If you have any more ideas i'd appreciate them. I never tried using a current limiter, at a risk of sounding dumb how would that work.
Thanks again


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In the classic variac setup, you power the unit under test via the variac. That way you can start with zero voltage on the mains and then turn it up a little at a time to see if excess current draw starts to happen. You of course also need a current meter in series with the load. If as you turn the mains voltage up the current meter swings over, stop and return the voltage to zero.

This way you never applied full power and further damage to the amp does not occur. This also saves blowing up new parts you just installed. The old flip it on to see if it is fixed yet approach burns up lots of good parts.

If you have no variac, an old trick will work better than nothing. Take a light bulb - I suppose a 100 watt or 60 watt bulb is a good place to start - and put it in a socket with a couple clip leads wired to the socket. Now you can remove the main fuse or breaker from a unit under test and clip the bulb in its place. If the UUT is shorted and would draw excess current, the light bulb comes on brightly and caauses most of the voltage drop. If the UUT is OK, then the light wil come on only dimly. The bulb prevents the UUT from getting hit full force with the mains.

Rather than clip leads, you could also put an outlet on a box and a lamp socket for the bulb and a power cord. Wire it up as an extension cord with the bulb in series of one leg.
Thanks Enzo, I'll have to try that. Also sounds like I added something new to my shops list of things to get. It'll have to wait a bit since I just forked out for a oscope and function gen. . Did you have a chance to look over the schematics to see if you had any ideas?
Thanks again
on that cs800, I replaced a couple of wirewound resitors that looked burned out at the connections, after pulling them off the board i tested them and they where bad, I then ran it through it's course, it seemed to work fine. I got a smoth sinewave at the output. but the ddt never lit up, is that normal for this unit. I'm going to have to look at it a bit more, I'm not much on pa amps, mostly I work on guitar amps.
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Make sure you tighten all screws of the TO3 cans. (Don't solder them to the board). Give the PSU capacitor screws a firm turn as well. Resolder the flatcable connections that run from the driver board to the power board even if they look OK. Confirm that the DDT circuit works by applying a strong enough input signal.

/Hugo :)
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