Peavey Nashville 400 reverb tank.

[Alan Cook]

I’ve just cleaned the pots on my Nashville 400 and they work perfectly now. Very happy with that job, but I also removed the reverb tank and found a piece of cardboard underneath the tank inside the dust cover!
Should that be there?
And does the cover serve any other purpose other than keeping dust out?
Ive refitted the tank using the grommet fixing holes and it works perfectly.

[Jerry Overstreet]

Yes, the cardboard is standard issue with these amps. At least for the few that I've examined. I'm not sure but I'm guessing it offers some sort of insulation, from either shock or electrical interference. The bag? Probably just dust shield and a quicker way of mounting with just one screw securing the bag to the cab instead of using those 4 grommet holes.

I've noticed several other amps that don't use either and some that are solid mounted to the cabinet as you describe, so it's importance, I can't say.

[Bill A. Moore]

All the older Amp builders used the cardboard, Fender also had 2 strips of wood that sandwiched the cardboard to the tank. It and the bag mounting was an attempt to isolate the springs from vibration from the cab. My 80's Music Man used tape rather than screws to hold the cardboard to the tank. You may also find foam tape on the tank itself to help dampen vibrations.
When I install a tank I use Leo's method, even when replacing the units screwed to the cab using rubber grommets!

[Alan Cook]

Thanks for the replies and information, I’m using the 400 as a studio amp at the moment but I was thinking about splitting it to an amp and cab to help with the weight issues. I’ll refit the cardboard and dust bag when I do.

Alan.