GK preamp failure-what to do

Discussion in 'Amps [BG]' started by poorbassist15, Jan 6, 2014.


  1. poorbassist15

    poorbassist15

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    At my gig Saturday, I plugged in my amp at soundcheck and played one note before I lost all signal and the preamp light showed overload even with gain all the way down. I plugged in through the effects loop and was able to finish the night but this scared me. It was popping and sizzling at one gig a month ago but has been fine ever since. This amp is now a serious liability and I'm considering getting a CS800 and replacing it but is there anything that can be done to fix it?
     
  2. B-string

    B-string Gold Supporting Member

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    Sure the preamp is usually very easy to repair.
     
  3. odin70

    odin70

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    You could write to GK and wait for them not answering you.
     
  4. B-string

    B-string Gold Supporting Member

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    I've never failed to get an answer from jason@gallien.com except when the plant is shut down for two weeks every year at the end of December?
     
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  6. BassmanPaul

    BassmanPaul Gold Supporting Member

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    Those guys must throw a hell of a New Year bash if no one can work for the next two weeks!!! :D
     
  7. B-string

    B-string Gold Supporting Member

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    Depends I guess? I've worked for a couple companies that did this. Usually worked one of the two weeks maintaining equipment or scrubbing the corners ;)
     
  8. 4Mal

    4Mal Supporting Member

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    Or taking inventory...

    Interesting that the Op was able to continue by using the effects loop. One poibilityis that the effects loop jack itself is bad. Often the send is a switching jack and if the switch grounds, bad stuff can happen plugging into the effects reteun in that case often works.

    Try inserting a guitar cable into the effects send and back into the return. If the pre comes back to life, the jack is probably the issue. Barrng that, yeah, get a hold of Jason. The few times I have needed support I found GK very responsive.
     
  9. will33

    will33

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    This^^

    Always try the simple stuff first. Clean the effects jacks, or at least connect them with a patch cable.
     
  10. B-string

    B-string Gold Supporting Member

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    The "clip light" staying on with no sound would lead me to believe a failure in the preamp or +/- 15 or 35volt supply. Never hurts to check the effects loop.
     
  11. jeff7bass

    jeff7bass

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    I want to work for GK! I applied at Carvin but they're so busy during the holidays sellings great gear at special prices that I said, "forget it".

    :bag: :D
     
  12. B-string

    B-string Gold Supporting Member

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    You can't get a job by giving up. ;)
     
  13. jeff7bass

    jeff7bass

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    I'd have to move to Southern California, away from the 20 inches of snow and -45 degree wind chills we have in Chicago right now.

    :bawl:
     
  14. B-string

    B-string Gold Supporting Member

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    Well, it is hard to find -45 in SoCal but snow is usually only a couple hours away! :D
     
  15. Troph

    Troph

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    I'm guessing this was some kind of RB series amp?

    If there is one common failure spot I've noticed on the RB-series amps, it's in the preamp board. I love these amps, but the preamp does seem to give more trouble than other components. Maybe it's extra sensitive or more prone to abuse from input signals.
     
  16. B-string

    B-string Gold Supporting Member

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    According to the OP's profile a 400RB IV.
     
  17. Steve Dallman

    Steve Dallman Supporting Member

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    Any halfway decent tech could troubleshoot this quickly. The schematics for the preamp are all over the internet.
     

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