Warmer 12AX7

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by fridgit, Jun 2, 2008.

  1. fridgit

    fridgit Member

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    .....with a smoother top end, is there such a thing? I'd like to try one in my V1 spot to see if I can tame some of the brightness in my amp.

    Would a 5751 be better?

    Maybe a 12AT7?

    School me please!!!

    Thanks!
     
  2. scottl

    scottl Member

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    Why don't you mention what amp, and also what speaker and guitar you use?

    Asking for tube advice without these details is futile.
     
  3. Blue Strat

    Blue Strat Member

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    Knowing what tube you DON'T like would help in recommending something different that you MIGHT like:)
     
  4. Jahn

    Jahn Listens to Johnny Marr, plays like John Denver Supporting Member

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    Well, I was fooling with my rackmount Chandler Tube Driver and the stock Sovtek 12AX7 in there was pretty darn fizzy and buzzy when driven. Maybe good for those sizzling hair bands, but not for me. I put a US NOS GE "5-Star" 5751 in there and the grind and growl was still there, but the fizz was definitely tamed down. Hope that helps.

    [​IMG]
     
  5. fridgit

    fridgit Member

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    EVH 5150 III w/ matching cab (Celestion G12EVH speakers). I know I need to break in the speakers a bit more too. I've had the amp for 11 months now, but have only played at moderate volumes.
     
  6. fridgit

    fridgit Member

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    Cool, thanks!!!
     
  7. scottl

    scottl Member

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    Try some older ANOS tubes. Stuff like RCA. Your amp probably came with some cheap stuff in it. I'd stay with the 12AX7 for now, but try some better tubes. If you are not using JJ ECC83 in there, you may want to try a couple of them (for readily available and inexpensive new stuff). They are a little darker than Sovtek for instance.
     
  8. jay42

    jay42 Member

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    You might like a 12ay7.
     
  9. TweeDLX

    TweeDLX Member

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    A true tone fanatic should have a collection of different types and brands on hand. At least, that's my approach. Tone being subjective, you never know what combination is going to make the amp sing to your ears. The Tung-Sol Re-issues sound good to me, but I've seen other posts where they were described as unreliable. Mine work fine.

    Mike [​IMG]
     
  10. telemoxy

    telemoxy Member

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    A 5751 did exactly what you are looking for when I replaced the 12AX7 with a 5751 in my Hughes & Kettner Cream Machine (yes it is a tube amp).
     
  11. shaun

    shaun Member

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  12. ruger9

    ruger9 Supporting Member

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    A 5751 will be warmer, but it will also lower the gain. Ditto a JJ ECC832/12DW7.

    The warmest current-production 12AX7's I have found are the GT12AX7M (good luck finding any), the Tung-Sol, and the EH12AX7 (Electro-Harmonix; not sure who makes the tube for them, but they are a mid-heavy tube, and I think would be great with an EVH 5150).
     
  13. Blue Strat

    Blue Strat Member

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    Good luck because many dealers have stopped carrying these due to HORRIBLE reliability and high reject rates.
     
  14. telemoxy

    telemoxy Member

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  15. scottl

    scottl Member

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    Using anything other than a 12AX7 or 5751 will, IMHO, thin your tone. Those tubes have a much lower plate resistance and will result in a loss of bass as well as some increased high end bandwidth. No problem trying them, but they also have dramatically different current draws as well as the above factors. You may affect your other preamp tube voltages if you start subbing tubes that the amp wasn't designed to handle. Try at the risk of your wallet.

    A better alternative is to check out the forums dedicated to your amp. Find what others are doing. There may be a circuit tweak that accomplishes what you want.
     
  16. Jahn

    Jahn Listens to Johnny Marr, plays like John Denver Supporting Member

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    That's what I found too. 12AT7 thinned my tone out. I didn't find the 5751 to decrease vol or gain, and the tone stayed nice and fat. The tube that really lowered vol/gain was the 12AU7, which sounded sweet but tamed it a bit too much.
     

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