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GK1001RB-II Problem

Discussion in 'Amps and Cabs [BG]' started by teej, Sep 26, 2008.


  1. teej

    teej

    Aug 19, 2004
    Sheffield, AL 35660
    Something just blew in my amp. It was playing fine this morning, and then just now, I plug in and hear this hum. It's almost like 60hz hum, but it's there regardless of the EQ, volume, whether an instrument is plugged in or not, etc. I tried using the other output, but get the same thing. And then there's the classic "fried component" smell. No magic green smoke, though, but I haven't opened it up to see what's going on. I'm the second owner, and have had it for a few years, but it's never been gigged and I live in an apartment, so the volume has always been low. I figure it's no longer covered by warranty, so should I send it right off to Gallien-Krueger?
     
  2. Trevorus

    Trevorus

    Oct 18, 2002
    Urbana, IL
    You could open it up and look, but I would send it off for proper repair either way.
     
  3. teej

    teej

    Aug 19, 2004
    Sheffield, AL 35660
    These capacitors are fried. The fuse is good, though.

    IMG_0498.
     
  4. Filter Caps? How's your soldering skills? :)

    - Andrew
     
  5. Trevorus

    Trevorus

    Oct 18, 2002
    Urbana, IL
    Those are not capacitors. Those are rectifiers... I suspected something of the sort.

    Something caused them to fry. Best to get it checked out. (or if you feel brave, replace them and try it. Sometimes components just go bad...)
     
  6. teej

    teej

    Aug 19, 2004
    Sheffield, AL 35660
    2 years of high school electronics, 4 years as theater tech director, and 6 years of guitar repair and making my own cables. I don't know if that's sufficient, but that's my experience. Or as I like to say, "I've never done it before, so I'll never know until I find out."

    I shouldn't have, but I did plug an effect pedal in while the amp was on. I forgot to mention that.
     
  7. Trevorus

    Trevorus

    Oct 18, 2002
    Urbana, IL
    Plugging something in shouldn't kill the amp, it's meant to have stuff plugged into it. Check your speaker cables and such and make sure there wasn't a short on that end.

    Mouser has replacement rectifiers that are a cross reference for the original ones. (They have original ones, but they are non-stocked and have an 1800 unit minimum order) http://www.mouser.com/Search/ProductDetail.aspx?qs=G5AQjGfRJcIujFZLRnXFKQ==
     
  8. teej

    teej

    Aug 19, 2004
    Sheffield, AL 35660
    That may not be what caused it, but it happen right after I plugged in the pedal. I figured since the pedal was on, and the amp was on, it got a little power surge or something. I haven't moved the amp or cabs in well over a year. Would the fault be in the speaker cables?

    I'll just take the amp to a repair center when I can.

    Mouser has EVERYTHING! Too bad about the minimum order. If I were expecting to blow a pair of rectifiers 900 times, I might consider it. :meh:
     
  9. Trevorus

    Trevorus

    Oct 18, 2002
    Urbana, IL
    That link I gave you is for a cross reference which would be a direct replacement. It's got no minimum order. Getting it sent in would not be a bad idea. I seriously don't think that the plugging in of an effect caused it. A tech should be able to figure out what did happen, though.
     
  10. JanusZarate

    JanusZarate Low End Avenger

    Feb 21, 2006
    San Francisco, CA, USA
    Effect Pedal = Cause?

    Extremely unlikely. There simply isn't enough voltage to pose a threat unless your effect demands a high voltage and it was terribly miswired - in which case, your effect would be fried, too, and possibly you as well (don't touch your bass! :D).

    Talk to anyone in the effects forum... if thousands (if not millions) of us use effects without harm, and if guitarists can do it too...
     
  11. teej

    teej

    Aug 19, 2004
    Sheffield, AL 35660
    Would playing a guitar through the amp do anything? I've been working on an old no-name thing easily from the 60s, but don't have a guitar amp, so I'd occasionally strum a few chords (at low volumes, of course) just to make sure everything is still working. It's got a low-output DeArmond-style pickup. Sounds VERY jazzy.
     
  12. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    nope. That wouldnt do it ...
     
  13. JanusZarate

    JanusZarate Low End Avenger

    Feb 21, 2006
    San Francisco, CA, USA
    Nope. That's harmless.

    Bass amps are not only for bass. They were invented in light of the fact that guitar amps can't bring out the best of a bass. What that means is simply that a bass amp is better suited for what a bass "should" sound like, especially in regards to low end.

    You could easily use your bass rig as a stereo system for your music. It may not sound "right" though, only because the amp and speakers are voiced with a different sonic result in mind (while a good stereo system, a PA system, etc. usually tries to reproduce exactly what it's fed).
     
  14. Trevorus

    Trevorus

    Oct 18, 2002
    Urbana, IL
    This is not an issue with signal, this is an issue with the electrical power section. Those rectifiers failed, and that is what's causing this amp to be non-functional. It's a component failure, plain and simple.
     
  15. tadawson

    tadawson

    Aug 24, 2005
    Lewisville, TX
    What minimum order? I order stuff that is $5 or $10 bucks from them all the time . . . .

    From their web page: "Minimum Order: NO MINIMUM ORDER on items normally stocked in our warehouse. "

    You only hit minimums on oddballs or special order items . . . very unlikely for this type of parts!

    - Tim
     
  16. teej

    teej

    Aug 19, 2004
    Sheffield, AL 35660
    I went ahead and ordered replacement rectifiers from Mouser. I only needed two, but they're cheap, so I bought four. I think I'll replace them myself, but if they blow again, then something must be up, as suggested by the guy who shares my name (Trevor), at which point, I'll have no choice but to take the 1 1/2 hour drive to Huntsville to have it serviced.

    In the meantime, I think I should seriously think about getting a second amp (a combo, maybe 100w), so that I can stop using my gigging amp and cabs here in the apartment.
     
  17. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    Trevor, if you try to replace the bridges yourself be careful that you do not damage the PCB with too much heat. All four joints will have to be melted at the same time to get the things out. If you can cut the legs on the component side, even if you have to destroy the old part, then you can deal with each joint separately. Clean the remaining holes of solder and then the new bridge can be inserted and soldered into place. Make sure you orientate the new part correctly or you'll have even more problems. Before you insert the new part check for shorted caps from the + and - legs and ground.

    Paul
     
  18. teej

    teej

    Aug 19, 2004
    Sheffield, AL 35660
    Well the old parts are fried (literally) and fused together, so I've got no emotional attachment to them. :smug: The new rectifiers came in, and I've started unhooking everything (while making a diagram of where everything goes so that I don't screw it up later), so I'm hoping to have the amp going again by bedtime.

    In news unrelated to the specific thread title, but still related to my lack of an amp, I bought a Hartke 1400 head for $101 (shipped). You can read the thread for it for the details, but basically, I'm going to make a little combo out of it -- possibly a single 10 or 12. I might consider a 15, though.
     
  19. teej

    teej

    Aug 19, 2004
    Sheffield, AL 35660
    I pulled the PCB, but I can't unsolder the 4 leads of each rectifier at the same time to pull them out, and the components are too close together to get my wire cutters underneath to cut out the old part and deal with each lead individually, so I guess I'll have to take it to an authorized shop in Huntsville (1 1/2 hr. drive) and have them deal with it. :meh:
     
  20. teej

    teej

    Aug 19, 2004
    Sheffield, AL 35660
    Scratch that last post.

    I was able to isolate the individual leads by wiggling the components until they simply snapped. The new rectifiers went in, the wires were reconnected, and everything went back together, only to have about 5 minutes of hum-free playing before the hum returned. Funny thing, though... now the hum gets louder or softer, depending on how high or low I have the volume. Before, it was the same regardless of levels.

    The rectifiers are holding, though, but it seems I'll still have to take it in for repair. :(

    EDIT: Well, I unplugged everything, rechecked the connections (everything was OK), and plugged back in. Played several songs at low volumes with zero hum. :meh: I'm not sure if it will do it again, but in the meantime, I'm going to enjoy having my amp back! Just to be on the safe side, though, I'm going to take it to Huntsville anyway to make sure everything is in working order. You know, like a routine check-up. :smug:
     

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