Peavey CS 400

[Bill F777]

Just bought an old style Peavey CS 400 {Aluminum Front}. It was only $40.00 so how can you pass that up. It was full of dirt, and the only problem it had was the input potentiometers were very scratchy. So I got out the air hose, blew out the dirt and cleaned the pots. That amp is great sounding, I didn not expect it to sound as good as it did! Totally quiet when you kill the input signal. It sounds a lot better than the new style CS 400 {black plastic front} I can't believe the difference there is in commercial power amp sound. Anybody have any advise on using such an old amp on a daily basis, I think it should be rebuilt, as in new caps, I might even design a circuit to kill the power if a final transistor shorts, I don't want to fry any speakers.

[Old Guy]

That was an excellent amp back in the day.

There are arguments, but basically- RCA published some designs for their transistors...those designs developed into a series of amps by BGW...

The fellow who did the RCA designs wound up at Peavey-

The CS800 is similar to a BGW 750..don't remember checking the 400, been a long time since I saw one, but would expect similar circuitry...

I lost a lot of sales to those Peavey amps- their speakers I could beat the pants off of...but the amps were good. Some of the mixers were decent also.

The BGW does have much better speaker and amp protection...

[bfish]

As far as further service, if you can get the service lit, see if there are means for internal adjustments, such as bias or DC offset, and set those to spec. Electrolytic caps are always suspects in gear that's either old or unused for a time, but if it's quiet at full gain and there are no turn-on pops they're probably OK.

I always admired the Altec 9440A protection circuits, but for a $40 amp I'd probably buy a fuse and call it good.

[Old Guy]

http://www.eserviceinfo.com/download...vey_CS400.html