Vibrochamp issues

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by orcmonkey, Oct 11, 2006.

  1. orcmonkey

    orcmonkey Member

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    [FONT=Verdana, Arial]Hey guys... I'm new to working on amps but I thought I had done alright. After reading tons of stuff online and being very careful with safety/cap discharge, I just installed a new 3 prong cord in my vibrochamp, as well as changing out the cathode resistor to 1k ohms and the bypass cap to 50/50. It sounds better, and is safer now, except i have a weird new problem. The amp powers up and works fine, then after a few minutes I start to hear a scratchy noise every now and then, similar to a scratchy pot, even though im not turning any of them. I plan on cleaning the pots soon b/c the tremelo ones are quite scratchy, but this seems different. One time when it did this the noise didn't go away until i powered down and waited a bit. Any ideas, I'm thinking I might have loosened a solder joint or something when I was in there working on it.[/FONT]
     
  2. brad347

    brad347 Member

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    sounds like a bad/intermittend solder connection. Go back and check all of yours thoroughly. How did you attach the green (ground) wire of the 3-prong plug to the chassis?
     
  3. orcmonkey

    orcmonkey Member

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    What I did with the green wire is solder a ring terminal to the end of it, then put it over one of the chasis bolts, then screw the nut over it. I'll admit my soldering skills aren't the best, so I'll go back and check them, but any idea where in the chasis a bad solder would cause this?
     
  4. teleamp

    teleamp Senior Member

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    Check all the places you soldered, make sure the solder has flowed and is not just setting on the leads. Also, make sure that where the ground eyelet is bolted is clean.

    Mike
     
  5. brad347

    brad347 Member

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    do you mean one of the transformer bolts? This is the best place to do it if you use this method.
     
  6. orcmonkey

    orcmonkey Member

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    Yeah I mis-typed, I meant transformer
     

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