pr rav ringing reverb

[scole]

my pr has a ringing sound as with the reverb. is that the rev pan? does the tank bag prevent that?

[ahamay79]

The bag does help prevent some of it. Make sure the cardboard piece is in there, too.

Have you tried new tubes for the reverb driver and recovery?

[scole]

its a new build. the tanks dont come with cardboard. do i just cover the bottom of the tank?

[ahamay79]

its a new build. the tanks dont come with cardboard. do i just cover the bottom of the tank?

Yes. Just cut a piece of corrugated cardboard the same size as the bottom of the reverb pan.

Cardboard goes in the bag, pan goes in the bag, open side down on top of the cardboard. Some folks like to "double bag" the reverb.

Screw the bag down to the bottom of the cab. You only need one screw per end.

If that doesn't work, try a new pan.

[ahamay79]

How's the ringing ? You can also try swapping the reverb driver and recovery tubes with known good tubes and see if that works. Substitution is always easy troubleshooting method.

[Enzo]

The ringing is the pan feeding back acoustically, I doubt the tubes matter.

Isolating the innards helps. that is why we cover the open side with cardboard, and that is why we bag it.

DOn't screw it down tight, that helps cabinet vibration get back into the pan. Only turn the screws in enough to keep it from moving around.

Look at the pan itself. The upper surface of it is a long wide expanse of flat metal. Get some self-adhesive foam weatherstripping - the stuff you might stick on the garage door opening to keep out drafts, you know, maybe 3/4" wide - stick a long stripe of that along the center of the top. That will dampen any tendency for that metal to ring. CAr makers do that inside large body panels to tone down "sheetmetal" sounds.

And try moving it around, sometimes moving over a couple inches is all it takes.

And if all else fails, try turning the thing upside down.

[tubeswell]

Bubble wrap is another acoustic deadner

[ahamay79]

I had a fender reverb circuit ringing problem once. It was a microphonic tube. Never seen it since.