GK preamp failure-what to do

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

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


    Dec 26, 2007
    You could write to GK and wait for them not answering you.
  4. 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?
  5. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    Those guys must throw a hell of a New Year bash if no one can work for the next two weeks!!! :D
  6. 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 ;)
  7. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    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.
  8. will33


    May 22, 2006

    Always try the simple stuff first. Clean the effects jacks, or at least connect them with a patch cable.
  9. 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.
  10. jeff7bass


    Apr 9, 2009
    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
  11. You can't get a job by giving up. ;)
  12. jeff7bass


    Apr 9, 2009
    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.

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


    Apr 14, 2011
    Kirkland, WA
    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.
  15. According to the OP's profile a 400RB IV.
  16. Steve Dallman

    Steve Dallman Supporting Member

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