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5751 mechanical noise?

Discussion in 'Glowing Bottle Tube Amp Forum' started by Willie Johnson, Nov 23, 2020.

  1. Willie Johnson

    Willie Johnson Tele-Meister

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    Hi all. I put a JJ 5751 into my Champion 600, which I really like the sound of and helped to tame some of the gain and overdrive obtained by bypassing the tone and negative feedback loop to a happy (loud!) medium.

    However, the tube seems to have a sympathetic rattle/glass-and-metal tinkling sound when I hit certain notes (d sharp, iirc); is this a flaw in the tube, or is this typical? Crank it up until it doesn't bother me, or replace? I've chopsticked it, and it's not microphonic.
     
  2. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    If you're sure it's that tube, must be just a funky one.
     
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  3. Dacious

    Dacious Poster Extraordinaire

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    Nup not typical. Must have a loose element inside. If it's an online vendor you may be able to return.
     
  4. schmee

    schmee Doctor of Teleocity

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    Older tubes are a turkey shoot . MANY are noisy. But new? hmmmm...You just got a noisy one, it may work in another position if you need it sometime.
     
  5. Timmay

    Timmay Tele-Meister

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    Definitely not typical. I have quite a few of those JJ 5751's. Never an issue with any of them. They've become my favorite pre-amp tube in most of my amps.
     
  6. Burning Fingers

    Burning Fingers Tele-Meister

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    It is a flaw in the tube...I have come across this problem twenty or more times in amps brought to me for repair ..and the problem has been with various brands of tubes and not just with preamp tubes but power tubes as well.

    But it is rare for a new tube to do this.
     
  7. Willie Johnson

    Willie Johnson Tele-Meister

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    Thanks, dudes. I'm inclined to lump it and not return it, as it does sound great (what comes out of the speaker, that is). Appreciate the gut check.
     
  8. Paulie Walnuts

    Paulie Walnuts Tele-Meister

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    No need to buy any new production 5751 tube. As your finding out the quality leaves a lot to be desired. There are still tons of great tested or flat out NOS 5751 tubes available for not much more than you pay for the JJ. Spend a few bucks extra now and get a good 5751 tube and you’ll likely have it the rest of your life as they are built like a tank. Let me know if your unsure and I’ll gladly help you source a great tube without getting ripped off
     
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  9. tap4154

    tap4154 Doctor of Teleocity Ad Free Member

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    You just got a bad tube. I have a new 5751 JJ in my Super 210 V1 and it sounds awesome.
     
  10. Willie Johnson

    Willie Johnson Tele-Meister

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    Update--I put that tube into my new ec Tube Pilot pedal, and I like it; the rattling problem is solved being isolated from the vibration of the cabinet, and I much prefer the pedal's lower gain. I put a JJ 12ax7 in the amp and it's fine--the 5751 was a little sweeter and quieter, though.
     
  11. Paul G.

    Paul G. Friend of Leo's

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    Use a capo to hit the bad note, then with your left hand you can reach in and lightly touch the top of tube you suspect. If the noise stops, then it's a bad tube.

    Not uncommon -- lots of little bits in there, if any are even a little bit loose...
     
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  12. deus56

    deus56 Tele-Meister

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    +1 Sir. There are some great tubes out there.
    [​IMG]
     
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