Reverb tank bag vs spring mounts?

any of the fenders that I've owned have all had bags without the springs and mounted on the bottom. I always figured springs would be used in a different cabinet style possibly.

 

Fender used #6 screws and #10 washers to secure the bag the the cab....

https://www.tdpri.com/threads/princeton-reverb-build-3.958453/#post-9167519

 

The internal reverb pan is already spring mounted anyway???

 

I've always figured that the bag was intended to keep dust and crap out of the reverb tank, particularly the springs.

 

I have never seen a spring mounted tank.do you have pictures of those springs??

 

It also avoid Larsen effect.

-tbln

 

My Fender stand-alone reverb unit had the tank spring mounted.

 

It's to dampen vibration. Leo and his boys used bags in the reverb combos. In combos, the speakers vibrate everything all the time, especially the cabinet. So... Fender didn't attach the tank to the cabinet, they slid it into a bag and then loosely attached that bag to the cabinet. If you ever check the bag connection in a BF Fender there is some slack in the bag between the two screws and the screws are not tightened all the way down, that's intentional. The thick bag, the loose tension, and the poor connection to the cab inhibit the amount of vibration transferred from the cab to the tank.

Pre-CBS Fender didn't see a need to do this with the outboard reverb, and they never built a reverb head, so we don't know if they would have used the bags then.

 

Bandmaster Reverb? Ah, '68.

 

There seems to be some confusion here -- "spring reverb" doesn't mean "spring mounted." Some free-standing reverb units do suspend the tank in space on 4 diagonal springs. I've not seen that done in a combo -- where would you suspend it? Weber may well have a method, but 'generally accepted preference' would be bag.

As @Wyatt said, the bag shields the tank from some vibration and more important *decouples* it from the cab. For this you want some slack in the bag *and* you want the tank free to move a bit in the bag. Folks use several methods; I screwed the tank to a couple strips of lath and Elmer'd some slick corrugated board to them to pad it a bit and to 'slide' inside the bag.

 

I do that, and use the isolation rubber washers to screw the tank to the lath strips.

 

By "screw it all down" I assume you mean the bag (FTW it's nice to install grommets in the side folds rather than just screw right through the fabric). Or do you mean the piece of wood? Screwing *that* all down would screw it all up.

 

A ‘68 Bandmaster Reverb was a CBS amp. Iirc, CBS took over on Jan 4, 1965. The circuits that were introduced in the summer of 1968 were the first CBS designs. So, Wyatt’s observation about pre-CBS heads...Bandmaster and Showman amp...not having Reverb is accurate.

 

Yup, I saw that, thanks. I'm just making tons of friends this week.

 

It is all good, tele_savales.....brothers of the vibrating strings we are.