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when does a preamp issue belong in the repair forum?

Discussion in 'Hardware, Setup & Repair [BG]' started by Steve, Jan 9, 2018.


  1. Steve

    Steve

    Aug 10, 2001
    1.JPG
    I think...right now.

    I have a big old 4 module bartolini preamp sitting inside a '97 Tobias Classic that has a major malfunction and needs to be removed for service and repair ( I'd rather fix the original than replace it but, the problem is the same either way)

    Some mook at the Gibson shop saw fit to glue all those modules down so they can't be moved and the pots don't have anywhere near enough extra wire to play games with.

    Here's the other half of the problem: The quilted maple top has become unstable and has over time, developed a couple of hairline cracks along the grain from a couple of the pot shaft holes.

    Trying to muscles those modules out when all that torque is going to go straight into that cracked top is pretty much a non starter for me. I'm not even sure it's one of those things I want to watch done by a professional.

    Any suggestions on how to proceede with getting that ^%$# out of there or any suggestions as to who we know that might have the 'nad and knowledge would be greatly appreciated.

    This really isn't a money issue, that horse and I have been riding together a long time. I need a Jedi.
     
  2. 96tbird

    96tbird PLEASE STAND BY Supporting Member

    Sacrificial router bit comes to mind. Heat, solvent just about anything else I can think of is going to either ruin the wood or the plastics in the preamp so.... router?

    Congrats. This is the first preamp question that actually belongs in repair!!
     
  3. How do you visualize using a router? I'm having trouble figuring that out....
     
  4. sissy kathy

    sissy kathy Back to Bass-ics Gold Supporting Member

    Apr 21, 2014
    Arbutus, MD
    With a cracked top, consider removing the preamp piece meal, destroying it. You can use a hair dryer to soften hot glue enough to make it release. Is that copper shielding I see in there? That makes the hair dryer an even better option.
     
    Last edited: Jan 9, 2018
  5. Steve

    Steve

    Aug 10, 2001
    chop it out and save the top was my first thought, if it was any other preamp it would be out already.
    Man, I'd hate to trash that thing. I doubt I could ever get it replaced.

    Hold my beer and hand me that Dremel tool....I was wondering if the heat would soften the glue enough. The drop in humidity in the house from running the heat in Florida has opened those hair line cracks as much as I have ever seen. I'll probably wait until they get a little more normal looking. It is shielded with foil. The glue on that stuff is as strong as the modules
     
  6. sissy kathy

    sissy kathy Back to Bass-ics Gold Supporting Member

    Apr 21, 2014
    Arbutus, MD
    Ya missed my point. With the shielding there that means the modules are glued on copper; not many glues adhere well to impervious metal.
     
    Steve likes this.
  7. Steve

    Steve

    Aug 10, 2001
    That stuff adheres just fine. Whatever they used, it wasn't the small drop of silicone caulk they needed, there is ZERO flex on any of those modules. I already shoved way harder on them than I was comfortable. I'd heat it but...Ima not sure I want to roast those two cracks.

    I wonder..if I could find some stiff enough, flat and thin enough piece of some metal I could get red hot and slide under that module and melt the glue or whatever without baking the hole top over the cavity.

    Guess I'll have wait until the wife leaves so I can go into the kitchen and find a nice spatula to cut up for the tool I think I may need to make. I need a SlimJim about a half inch wide and 3 inches long...with a heat proof handle.

    :)
     
    Last edited: Jan 9, 2018
  8. 96tbird

    96tbird PLEASE STAND BY Supporting Member

    Set the plunge to just touch the level of the glue and have at it.
     
  9. Steve

    Steve

    Aug 10, 2001
    preamp soup. Powdered, just add water ^

    Finally reaching the age of "old enough to know better" has it's advantages for me and that piece of wood
     

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