rebuild from scratch or what..

Discussion in 'Amp Tech Center' started by ce24, Mar 4, 2013.

  1. ce24

    ce24 Poster Extraordinaire

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    I have vibrochamp clone that ive used as a bit of a modifying platform and it has developed a hum and I can't find it. Ive checked all solder joints. I'm thinking of taking it back to just parts and doing a complete rebuild and replacing all parts that might create hum...caps mainly......what do all yoiu builders think of this idea.

    thanks in advance.....
    cant do pics yet ..... amp not in my house...

    ce24
    ps brought this over from amp central
     
  2. muchxs

    muchxs Doctor of Teleocity

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    Stock layout or custom?

    Pics are super important. I've cut this layout apart, twisted it and put it back togther.

    The more creative you get, the more you're takin' chances with hum.

    There are some general rules:

    Keep the power supply and preamp as far apart as you can.

    Pay attention to proximity of controls to the power supply. You really don't want your control panel to continue to the power supply side of the amp.

    Keep your wires as short as possible.
     
  3. ce24

    ce24 Poster Extraordinaire

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    stock layout except for the tonestack switch. I'll look at what you say when I get to the amp....and take pics...it'll be 2 weeks. it's at our other house.....we're in the process of selling the curerent abode and moving to our retirement place.

    cheers ce24
     
  4. muchxs

    muchxs Doctor of Teleocity

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    Another thing to consider with Champs 'n' Champ clones:

    The ol' 22772 power transformer supplies a little over 400v unloaded. I should say supplied a little over 400v unloaded in '64 or '65 when the voltage at the wall was 115v-117v. Now it's 125v in some places.

    Combine that with an eBay "primo" tube set including a Sovtek rectifier or omit the the rectifier tube in a clone. Just use 1N4007 diodes.

    ...supply voltage goes over 450v.

    It doesn't take too many whacks over 450v before your capacitors cease to be capacitors.

    Just in general. 'Cuz we have two weeks to talk about this. :D
     
  5. ce24

    ce24 Poster Extraordinaire

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    ok so by taking the tone stack out and doing your "carr" mod may I have slammed the caps too much?....boy it sure got louder when I did that but Ive gone back to orig cept for the tone stack switch.

    thx
    ce24
     
  6. muchxs

    muchxs Doctor of Teleocity

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    Taking the tone stack out doesn't hurt a thing. If there's any hum the extra gain will sure let you hear it, though.

    What are you using for a power transformer?

    What are you uisng for a rectifier?
     
  7. ce24

    ce24 Poster Extraordinaire

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    5f2pts from the triode kit website and a 5y3 rec. It is a triode usa kit.
     
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