1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  

A Question to the amp electronics experts.

Discussion in 'Amps and Cabs [BG]' started by Andre_gt7, Jul 31, 2007.

  1. Andre_gt7


    Jan 4, 2005
    Atlanta - GA

    I own a Trace Elliot GP12SMX Amp+Power Amp combo that i use with a TE 4X10. It is an older pre-gibson model.


    Recently I've had 2 problems with it that are driving me crazy. I have little electronics knowledge.

    1) The "INCREASE GAIN - OK - OVERLOAD" leds next to the input jack and Gain knob are not working anymore, they just died.

    2) (Most serious problem IMO) Whenever i make a change on the Gain knob. The sound becomes "crackly" and only returns to normal when i turn the amp off and then on again.

    Thanks in advance for any help:bassist:

    P.S - Taking it to a tech to fix it is not an option, but I know someone who has good electronics knowledge and wouldn't mind making the repairs for me, granted i find out what needs to be done.
  2. Andre_gt7


    Jan 4, 2005
    Atlanta - GA

    really need some help guys. Thanks
  3. I believe you'll be hard pressed to find someone to accurately diagnose your amp problem without it being on a test bench and having access to test equipment. Why is a tech not an option?

    If the problem always happens after turning the gain pot, I would first try cleaning the pot and checking it for a cold solder joint. Or replace the pot. It's possible,though, that the LED failure is also related and a tech really needs to look at it.....good luck
  4. Hmmm... Those strange details you described somehow sound rather familar. My guess is the issue is related to the input jack. A failing or 'intermittent' input jack can cause some very odd behaviour in an amp.
  5. fdeck

    fdeck Supporting Member Commercial User

    Mar 20, 2004
    Madison WI
    HPF Technology LLC
    I agree with Rattman. Two things can happen. One is that the jack loses proper contact with the chassis. The other is that stress due to flexing of the jack causes solder joints to crack. Both of those things are easy to fix if you are comfortable about working on the amp safely. In the case of the solder joints, you just re-melt them with a bit of new solder (mainly to provide flux). A dodgy ground might make it hard for the circuit that measures the input level and drives the indicators, to get a good reading.
  6. Andre_gt7


    Jan 4, 2005
    Atlanta - GA
    Thank you all for the insights. A Tech is not an option b/c im short on money right now. I'll get the amp tomorrow and try cleaning the pot. I'll check the grounds and solders as well around the input jack.

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.