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Problems with amp overheating...help?

Discussion in 'Amps and Cabs [BG]' started by twotonetommy4, Jul 25, 2012.

  1. twotonetommy4


    Jul 25, 2012
    Hey guys, brand new to TalkBass, but couldn't be more excited to hear what some of you guys say and if you can help me out a bit...

    So lately I've been having a problem with my Gallien Krueger 700RB-II overheating during my gigs.:bawl: My volume knob is barely at 10 oclock. I play the head through an Ampeg 4x10 HLF classic cab. I also use a Boss ME50B multieffects board. The GK head is enclosed in a RoadReady case with no air between the head and walls of the case (which I think could maybe be the problem) but strange because I've owned the head for over a year now with the RR case on it and just started experiencing the problem. Any ideas as to why the GK head is overheating? Is there an external fan I could buy to help? I'm pretty bad with all the tech stuff, and every music store in my city sucks at fixing amps, any help? Thanks in advance!
  2. RickenBoogie


    Jul 22, 2007
    Dallas, TX
    By your description, the lack of ventilation seems the only likely cause. Maybe tack it out of the rack, and test the theory?
  3. twotonetommy4


    Jul 25, 2012
    will do. do you think my setup is okay? You don't think the GK is too powerful for the Ampeg cab?
  4. +1 The owners manual requires that there is a least 1/2" of free space above the amplifier for proper ventilation. I'd leave a blank space above the amp to make sure.

    Edit: Make sure the internal fan is actually running and you could check for any accumulated dirt inside the amp.
  5. will33


    May 22, 2006
    The cooling fan is on the top of the amp. It needs an open space above it.
  6. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    It might be a good idea to open the amp (or have a tech do it) and see if it is full of dust. If it is, the heat isn't being dissipated efficiently enough and could contribute to the overheating.
  7. JEBassman

    JEBassman Supporting Member

    Jun 25, 2008
    If running the head outside of the rack doesn't improve things, it might be time to find a tech who can check your amp and make sure that it's functioning up to specs.

    Also, what are your EQ settings like? How you adjust your EQ can have a big effect on headroom.

    I hope that's helpful; good luck.

  8. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    I'm pretty sure it's the rack causing it from what you've said. From what you haven't said, who knows? ;) But your cab should be fine with that head. Just use common sense and ears, and if you hear the cab farting out, back it down.
  9. petrus61

    petrus61 Supporting Member

    My 700RB II's rack case is plywood...I cut a big hole just over where the fan is located to allow the air sucked in through the front vents to escape through the top fan. That amp runs hot so it would be murder not to allow it the proper venting.
  10. Actually the fan sucks from the top of the case and out the front of the amp. With no space above the amp and case for air to flow you may have burned out the fan. At the very least remove it from the case and have the amp cleaned of dust.
  11. georgestrings

    georgestrings Banned

    Nov 5, 2005
    This, except I don't leave a blank space about mine - although I do make sure I have atleast 1/2" clearance...

    Verify that the fan is working as it should, then pop the top cover off and make sure the inside isn't too dirty... If neither of those aren't the problem, make sure there isn't an issue with your cab - and if all that checks out, it's time to send it in to G-K for a check up...

    - georgestrings
  12. Bassamatic

    Bassamatic keepin' the beat since the 60's Supporting Member

    One of the most common problems with computers is the fan dying and the processor overheating. Some are so quiet you don't notice they have stopped. The same thing can happen with your amp.

    It can also be the fan control circuit. Some are variable speed and temp controlled.
  13. twotonetommy4


    Jul 25, 2012
    thank you guys so much for the help. I'll be performing a little surgery tomorrow, making sure its clean and then running it outside of the rack.
  14. georgestrings

    georgestrings Banned

    Nov 5, 2005
    FYI, the fan doesn't typically run very much on those amps, even when it's functioning normally - you have to push it for a little while, and pump some lows thru it for a few minutes for it to get warm enough for the fan to kick in...

    - georgestrings
  15. will33


    May 22, 2006
    It's ok to run a component right above it in the rack if it's a shallow one like a lot of tuners/effects units, etc. are. The fan vent is still then open behind that piece to get air. If it's in it's own headcase, I'd just cut a hole in the top that lines up with the fan. I built a headcase for my SM400 that way, with holes that lined up with the intake and exhaust.
  16. will33


    May 22, 2006
    I think somebody did a rack ear mod for those so the amp sits an inch or 2 further back in the rack and the fan clears behind most common rack effects units, etc. Could have a local metal shop make you some. It's basically just a couple pieces of bent metal and a few holes drilled.
  17. petrus61

    petrus61 Supporting Member

    Correct. I get that backwards because the air is circulated so well throughout the head that one feels just a tiny bit of air from the front...unless you are cranking it for a good while, then you can feel some warm air coming out.

    I actually returned a pre Fender SWR Bass350 I got for like $50 because I thought the fan didn't work...turns out it was variable speed depending on how hot it ran. Guess I wasn't playing hard enough, lol.
  18. twotonetommy4


    Jul 25, 2012
    alright guys...so i opened up the amp...no dust. Left it out the case and played for almost an hour at gig level volume. The amp got VERY hot right over the vent of the fan. It didn't overheat, but feel like it was almost there. I also noticed that the amp was almost struggling to maintain its loudness...like it wasn't as loud as it used to be. Could I have blown something? What do y'all think? Thanks for the help guys.
  19. Yes, overheating can cause damage. If you know a good tech in your area (I.E. B-string in AZ, Paul, Mr. Foxen in the UK, Kent were I live, etc) I’d take it to them or have the factory repair. It’s a bummer you had to learn the hard way but at least now you know more about venting.
  20. jumbodbassman

    jumbodbassman Supporting Member

    Dec 28, 2009
    Stuck in traffic -NY & CT
    Born Again Tubey
    FWIW all my racks have a separate fan that helps move some air around. Most amps are made with vents on the sides or top beside the fans and cases just block the air flow. for over a decade if haved added an extra fan in a strategic postion in every rack i use. usual i try to blow " outside" air towards the vents to help bring cool air into the amp instead of just pulling air out qhich the internal fans do and which may actually be pulling hot air from normally trapped in the rack.

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