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Reverb tank bag vs spring mounts?

Discussion in 'Shock Brother's DIY Amps' started by Mark the Moose, Dec 29, 2019.

  1. Mark the Moose

    Mark the Moose Tele-Holic

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    Building a PR style amp and the kit came with spring mounts for the reverb tank. I’ve only ever used tank bags, is there a generally accepted preference of one over the other? If so, why?
     
  2. Mr Ridesglide

    Mr Ridesglide Friend of Leo's Silver Supporter

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    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.
     
  3. Phrygian77

    Phrygian77 Friend of Leo's Gold Supporter

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  4. galaxiex

    galaxiex Tele-Afflicted

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    The internal reverb pan is already spring mounted anyway???
     
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  5. rolandson

    rolandson Tele-Holic Silver Supporter

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

    Wally Telefied Ad Free Member

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

    tubelectron Tele-Afflicted

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    It also avoid Larsen effect.

    -tbln
     
  8. Ten Over

    Ten Over Tele-Holic

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

    Wyatt Tele-Afflicted

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    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.
     
    Last edited: Jan 3, 2020
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  10. tele_savales

    tele_savales Tele-Holic Platinum Supporter

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    Bandmaster Reverb? Ah, '68.
     
  11. King Fan

    King Fan Poster Extraordinaire

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    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.

    C57D23F8-2AF7-45C3-B733-A6B3E166F2D8.jpeg
     
  12. Mark the Moose

    Mark the Moose Tele-Holic

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    Planning to make a bag today out of some scraps of tweed pattern vinyl. I think I’ll mount it to a piece of wood inside the bag then screw it all down through some 1/4” truck bed mat I have laying around.
     
  13. bblumentritt

    bblumentritt Tele-Afflicted Platinum Supporter

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

    King Fan Poster Extraordinaire

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    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. :)
     
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  15. Wally

    Wally Telefied Ad Free Member

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    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.
     
  16. tele_savales

    tele_savales Tele-Holic Platinum Supporter

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

    Wally Telefied Ad Free Member

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