Can a new JJ 6V6 be substituted for a 6V6GT

Discussion in 'Amps and Cabs' started by ledzep618, Feb 29, 2012.

  1. ledzep618

    ledzep618 Supporting Member

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    Just picked up a new amp off the emporium, good buy, but one of the NOS 6V6's blew within 5 minutes of me turning the amp on. Can a matched set of current production JJ 6V6's be subbed in the for 6V6GTs?
     
  2. 5992

    5992 Member

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    Sure. They are the same tube designation. Depending on the amp, it may need to be rebiased. The JJs sound different than vintage/NOS 6V6s though.
     
  3. ledzep618

    ledzep618 Supporting Member

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    Thanks for the quick reply - I know it will sound different, but don't have the cash to shell out for NOS. Shouldn't need to be rebiased, the seller said it was cathode/self biasing
     
  4. 5992

    5992 Member

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    What amp is it? If you don't mind me asking.
     
  5. ledzep618

    ledzep618 Supporting Member

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    It's a handwired 5E3 clone
     
  6. Blue Strat

    Blue Strat Member

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    What, exactly, happened to the tube that blew? Sometimes it's an amp problem that blows tubes.
     
  7. ledzep618

    ledzep618 Supporting Member

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    I was playing the amp and started to get some pretty significant sounding crackles, walked around the back of the amp and kept playing and saw all sorts of sparks flying inside one of the 6V6 tubes...just assumed it was that one tube.
     
  8. 19181911

    19181911 Senior Member

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    Swap the power tube positions and see if the same tube is arcing inside, if not... If you have an amp tech available to you, have the tube sockets re-tensioned
     
  9. redshark1105

    redshark1105 Member

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    It really depends on the amp. If it's a modern design that was spec'ed with the JJ in mind then don't use NOS. But in a 5E3 clone I don't see why you can't use NOS glass. The reason is that JJ's allow a higher plate voltage, so if the amp was designed using JJ and runs over 420 on the plates then don't use NOS.
     
  10. ledzep618

    ledzep618 Supporting Member

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    Hey good idea...I just did that..no arcing. Also, the amp sounds a lot better. Could it be something as simple as the tube just not sitting quite right when I first put it in? Is that tube still okay to use in the other position or does arcing damage the inner works?
     
  11. Hulakatt

    Hulakatt Supporting Member

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    I've used JJ's in my 5e3 and they sounded ok but not great, too much headroom I guess. I really like the sound of the Sovtek 6v6's in a 5e3!

    BTW, the "GT" designation stands for "Glass Tube". Earlier tubes had metal construction instead of the glass. The metal ones could get pretty microphonic and the glass ones were an upgrade. So really any glass tube you get is a GT.
     

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