peavey classic 50

[Patrick l barenberg]

My peavey classic 50 makes a terrible distortion when shaken or moved while playing. I suspect the spring reverb, it is in a bag and could possibly be vibrating. Is a cushion or mounting screws an option? Love the amp otherwise. Thanks PAT

[g1]

You can't move or shake an amp that has reverb while you are playing it. You have to turn down the reverb first.
Or is the problem happening under normal playing conditions without moving or shaking the amp?

[Chuck H]

+1
All amps that use a spring reverb will do this. They always have. My solution is to either play through the amp OR move the amp. I've always found doing both at the same time to be cumbersome even with non reverb amps

Ok. All fun aside. Let's assume you have a peculiar situation where you want to use reverb and the amp will be in unsteady motion at the time (I'm imagining those pickup trucks in Cinco de Mayo parades with mariachi bands in the bed). You have the option of using a digital reverb in the effects loop (probably worse if you like moving the amp while using it because it will slide off the top). Some guys have replaced their spring pans with digital reverb units. I think this should require deriving power for it from somewhere. I've never done it.

[Paleo Pete]

I can't do more than confirm what these guys already said. My Super Reverb is set up the same way, spring reverb unit in a bag on bottom, if I bump the amp when it's on it makes the same nasty noise. Every amp with a reverb unit I've ever played would do the exact same thing. Peavey MX in a road case, ditto. Only cure I know of is to turn it off and use a rack mount or digital stomp box... I keep mine turned off anyway I use it so rarely and until I open it up again it has a hiss like frying bacon somewhere in the reverb section, it means so much to me I've just turned it off for around 4 years so far...don't miss it, I play a Champ that never had a reverb so much I don't miss it. Hiss is gone so it's definitely in the reverb section...And no it's not tubes, checked that long ago. Resistor most likely, I'll look for it next time I have a legitimate reason to open it up.

[überfuzz]

Use this feature to you advantage. If you ever debug a reverb, with the reverb on give the amp a wack. If you get a reverby noise it's the driver you need to check, not the collecting circuit...

[Patrick l barenberg]

Only get the terrible reverb distortion when the old floor gets shaking. I took off the castor wheels which might have caused vibrations and will just have to try not move it while on. I can use the standby or turn off or position the amp on a stable floor.

[Chuck H]

Indeed it sounds like there's not much to be done. Even if you added additional padding to the bottom of the bag I doubt it would have shock absorption under the weight of the pan to abate transfer from a shaky floor. I suppose you could climb underneath and shore the floor up.?. At least rearrange the room so the amp can be placed nearer to a corner which should shake a bit less than the rest. And there's still the digital option in the effect's loop or to replace the pan itself.

[Enzo]

OK, all spring reverb amps will crash the springs if you move it or bounce the amp. But some might be way more sensitive than others. IN that case, take the spring unit out of the bag and look in it. Are the four short corner springs still in place? Are any of the long springs broken free? The unit should sit in the bag, and the bag should have one or two screws holding it in place, the pan itself should never be screwed down tight.

[Chuck H]

OK, all spring reverb amps will crash the springs if you move it or bounce the amp. But some might be way more sensitive than others. IN that case, take the spring unit out of the bag and look in it. Are the four short corner springs still in place? Are any of the long springs broken free? The unit should sit in the bag, and the bag should have one or two screws holding it in place, the pan itself should never be screwed down tight.

Someone to show us the way. Obviously everyone here but you is operating on the assumption that this is the usual condition and Patrick is simply unaware of it. That was ineffective and short sighted. Better to determine if something is actually wrong. We are not worthy.

[Patrick l barenberg]

Thanks guys for all the input; took the spring reverb unit out of the classic 50, took it out of the bag and everything looked ok. Springs looked good and everything in place. Corner springs too. The bag is just screwed down to the chassis just as you said; replaced it all and played a while, didn't notice any crash problems. It must be a characteristic of a true spring reverb, a little touchy! Probably do need to shore up that old floor! Back playing! Patrick

[Tom Phillips]

Patrick,
When you inspected your reverb tank did it still have the cover plate (usually cardboard) installed on the open side? The cover would also normally have spacers that hold it about 1/4" away from the bottom flange. This is all needed to give the long reverb springs sufficient room to move without crashing. An improper, damaged or missing bottom plate can cause the springs to be more "crash" sensitive. The crashing problem can be made worse by sagging reverb springs too.

Attached is a photo showing the tank cover style that Fender uses. When it is installed in the bag it should be mounted with the opening of the metal reveb can oriented down. If it were mounted in the amp with the opening facing up that would also cause crash over sensitivity.

Cheers,
Tom

[Leo_Gnardo]

You can do what a couple of my customers have done - get an old NanoVerb or similar small digital reverb and plug it into the reverb send & return. Choice of reverb types, a couple extra tricks, and it never goes boing-ka-RASSH when the amp is rattled around. Make sure the mix is dialed full wet.

[Patrick l barenberg]

Tom, you may have solved the reverb mystery. It had the cardboard on the closed side of the reverb not the open side. The open side was correctly facing down but the cardboard was on top of the unit on the closed side! Someone might have put it in the bag on the wrong side. I replaced the cardboard on the open side between the chassis and the opening of the metal reverb. I will try it out again tonight but think this will cure the problem. The spacers were also there, thanks for the verification as I thought the cardboard should be on the open side. Thanks for the help. Patrick

[Tom Phillips]

...It had the cardboard on the closed side of the reverb not the open side...

Yea. That's a significant problem. Without the cover, wrinkles in the bag material could protrude into the pan and make it easy for the springs to contact them. In addition, the spacing could easily change every time you worked on the bag mounting in the cab. That would really confuse the issue since it could make the problem get better or way worse after the amp to a ride in the car. I'm glad you found the problem and that the cover plate was at least still in the bag.
Tom