How difficult to change 2 prong?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by raildog, Feb 27, 2009.

  1. raildog

    raildog Member

    Messages:
    379
    Joined:
    Jan 21, 2006
    Location:
    jonesboro ar
    Hello, just bought a gibson discover ga 8t and have found the 2 prong :confused:cord should be replaced as well as the death cap, is this something someone with very little soldering experience should tackle? also what is the death cap, thank you,Scott
     
  2. mark norwine

    mark norwine Member

    Messages:
    16,886
    Joined:
    Jul 25, 2005
    Location:
    NJ...GSP135

    No.

    Why do I say this? Because it's not about "soldering". It's about conceptual understanding of the task at hand. You're asking things like this:

    So I have to think you don't know what you're doing. I don't mean to be blunt, but line voltage can bite you.

    Nothing personal, but learning about electricity is best done in a book, or under someone's tutelage......not inside your amp, holding tools with which you admit to having little experience.

    Just sayin'....
     
  3. WaltC

    WaltC Member

    Messages:
    2,130
    Joined:
    Feb 21, 2006
    Location:
    Northern CA (Sacramento area)
    It's not particularly complex, but the GA-8T is a point to point wired amp and can be confusing to a neophyte. If you understand the concepts involved (the purpose of the three wires in a 3-wire plug, where's the best place to attach each, how to wire up a fuse holder the safest way, the importance of stress relief on the cord, etc.) then it's pretty straight forward.

    If not, then a trip to the amp tech is the best solution for you and the amp <g>.

    That said, and all warning expressed and implied, this is what it takes:

    http://www.netads.com/~meo/Guitar/Amps/Kalamazoo/Mods/R12-2to3Wire/
     
  4. WaltC

    WaltC Member

    Messages:
    2,130
    Joined:
    Feb 21, 2006
    Location:
    Northern CA (Sacramento area)
    Yup! But.... after 500V DC what's a little AC line voltage between friends.. <G>

    (just kidding of course)
     
  5. raildog

    raildog Member

    Messages:
    379
    Joined:
    Jan 21, 2006
    Location:
    jonesboro ar
    Its 3 wires, I am going to try it. Any partiular gauge cord? All the techs in my area don't seem amilar with the amp Thanks
     
  6. WaltC

    WaltC Member

    Messages:
    2,130
    Joined:
    Feb 21, 2006
    Location:
    Northern CA (Sacramento area)
    16awg wire will work fine. Get at least a 10ft. and (for me) preferably a 12 footer.

    You need a stress relief for it too and will probably have to drill out the existing hole to get it to fit properly.

    Caution, green to ground, white to the PT lead and black to the back (end) of the fuse holder, connect the other PT lead to the side contact of the fuse holder. Be careful, the caps can hold a 400+ DC volt charge for a looooong time and can bite you fatally if you're not careful.

    That said, go for the gold....
     
  7. raildog

    raildog Member

    Messages:
    379
    Joined:
    Jan 21, 2006
    Location:
    jonesboro ar
    [​IMG] has the deathcap already been removed when i follow the power cord one wire goes to the on off switch and the other goes to the fuse, i dont see any other connections, can you see something in the pic i am missing? thank you guy's for all the words of caution.Scott
     
  8. epluribus

    epluribus Member

    Messages:
    9,173
    Joined:
    Dec 14, 2005
    Hey Raildog. Yeah, I know the amp tech begged off, but any good radio nut can show you how to do probably one of the most useful and simple safety things there is--draining caps.

    Capacitors store deadly voltages in some cases, including the big electrolyitics in your amp. (Just google electrolytic caps and with very little reading you'll learn to spot 'em among all the spaghetti.) To get the voltage out, all you do is basically short the cap to ground so the power just goes zap. Trouble is, Zap can weld stuff and damage your tools, and it stinks--so there's a bunch of techniques and way-simple tools you can build to do it more cleanly.

    Best of all, it's a simple skill that takes two minutes max to learn, and no matter the amp, that your tech can teach you easy.

    But yeah, be dead-serious about being careful if you haven't drained 'em. That big voltage migrates all over the place in there. Goin' to the doctor ouch.

    --Ray
     
  9. raildog

    raildog Member

    Messages:
    379
    Joined:
    Jan 21, 2006
    Location:
    jonesboro ar
    Thanks from what i have read they are the silver looking cans, i will definately drain them before i do anything with the amp, thank you,Scott
     
  10. WaltC

    WaltC Member

    Messages:
    2,130
    Joined:
    Feb 21, 2006
    Location:
    Northern CA (Sacramento area)
    It looks like that "black beauty" Sprague cap that goes between what looks like the on off sw and ground is the "death cap". Once you install the new power cord you can remove it. Is it broken/cracked?

    Also, if you clip off the wire close to the cap and retain the wire "tail" that is soldered to the chassis, you can attach your green power cord ground wire to that "tail", solder it and have a good soldered connection to chassis ground.
     
  11. raildog

    raildog Member

    Messages:
    379
    Joined:
    Jan 21, 2006
    Location:
    jonesboro ar
    Hello, I cut the death cap before i desoldered the power cord, could that cause me problems? The tube sockets are not marked but i laid them out in the order i took them out, i put the grounded power cord on and replaced the tubes, and now power light is on but no pre amp and only 1 power tube is working, nothing else, any ideas? besides send it to a tech.thanks,Scott
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice