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Gibson GA 15RV Speaker Issue

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Shnook, Dec 22, 2005.

  1. Shnook

    Shnook Supporting Member

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    About 3 weeks ago I bought a Gibson GA 15RV. At first it sounded awesome. Clear, warm, and smooth. Then a few days after owning it I noticed a lingering note (ghost note?) on one particular note in the middle of the fretboard. In the meantime I hooked the amp up to my 2X12 cabinet, which disengages the internal speaker, and the mystery sound was gone thru the extention cabinet. Last weekend I tightened up some screws and whatnot in the Gibson cab and found that made the noise worse. So logically I loosened the ones I tightened and it seemed to go back to the normal thing with said mystery sound. Therefore, I've played the amp thru the 2X12 cab since then. This evening I decided to give the internal speaker another try and at first there was the mystery noise, then noise on more notes, and finally major noise sounding like someone pulling and scraping a chair across the kitchen floor. I plugged it back into the 2X12 cab and it sounds wonderful. So I'm ASSuming it's a internal speaker issue. The speaker in question is one of those Vintage 30 Celestions. Any idea from anyone on what's going on here? Thanks in advance!
     
  2. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    Sounds like one of two things...

    1) Cab resonance is being vibrated at certain points by the speaker, which accentuates it more with tighter screw pressure.

    2) The speaker has got a vibration itself, loose "something" in the speaker, or there's some kind of problem going on with the speaker.

    There could also be some other things, but these are what come to mind to me based on what you're posted... try a different speaker in there and if it goes away, then it was the V30, if it's still there, then it's the cabinet.

    Good luck.
     
  3. Shnook

    Shnook Supporting Member

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    Thanks for the suggestions. I think I may be looking for a new replacement speaker.
     
  4. Shnook

    Shnook Supporting Member

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    Just a little update. Turned out to not be the speaker but a 'bad' tube. I'd replaced the stock JJ tubes in the Gibson the night before this pronouced noise started happening. I put a NOS Brimar and a lightly used old RCA in there, which sounded just fine in my Classic 30. However, in the Gibson they made the amp unplayable. Weird. I put them back in the C30 just to see what would happen, and no problems what so ever in that amp. I replaced them with the original JJ's that were in the amp and all is well accept for that one note that buzzes and lingers.
     
  5. bob-i

    bob-i Member

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    I was gonna suggest that. What's most likely happening is you're hitting a resonate frequency that sets the tube off. The external cabinet doesn't transmit the vibration, and the Classic 30 doesn't accent that frequency.
     
  6. Shnook

    Shnook Supporting Member

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    Thanks for the info. I was kind of baffled at how a bad tube could sound horrible in one amp and really nice in another. Now it makes more sense.

    Thanks!
     

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