Got a vintage 12AX7... Now what?

Discussion in 'Glowing Bottle Tube Amp Forum' started by 50ShadesofOrange, May 22, 2020.

  1. 50ShadesofOrange

    50ShadesofOrange Tele-Meister

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    So I bought a Mazda 12AX7 from KCA, with the intent of trying it in my 1973 Vibro Champ.

    I could still do that, but then I started to wonder, might it be better used in the V2 of my TRRI?

    Perhaps it would make the Twin’s cleans even more beautiful, plus it might last longer than it would being pummeled in the VC.

    Or is my original plan, in the VC, still the way to go?

    I’m sure I could let my ears be the judge, but humor me. I’m locked down and looking for interaction beyond that of my wife and 5-year-old.
     
  2. telemnemonics

    telemnemonics Telefied Ad Free Member

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    IDK what the tubes do in a VC, but I prefer to not put a quiet slected tube in the PI slot.
    Does a VC even have a PI? Probably not since there is only one power tube.
    I'd learn what each tube position is doing first, but it's probably fine to try it in both slots you suggested.
    You don't want to put it in the last TRRI slot which is the PI, and also don't want to use it for the reverb driver or the trem.
     
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  3. Dacious

    Dacious Poster Extraordinaire

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    Mazda were actually British tubes. Try it in V1 of the VC or V1/V2 of the big amp.
     
  4. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Not a lot going on in a Champ, so you can really hear the tube changes.

    Why not try it in both places? v1 of the champ, v2 of the twin. See what you like. That's really all there is to it.
     
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  5. 50ShadesofOrange

    50ShadesofOrange Tele-Meister

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    I know. I know. You’re right.

    As much as anything, I was interested in the insights. Plus, never having the house to myself, my time to experiment at volume is pretty much nonexistent. :(
     
  6. Nickfl

    Nickfl Tele-Afflicted

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    What makes you think it would be "pummeled" in the vibrochamp and have a shorter life? The twin runs the preamp tubes harder and both are running at a fraction of the tubes max voltage or dissipation. Vibrochamps run their power tube notoriously hard, but the preamp tubes should have as long a life as in any other amp which should be basically forever in a normal preamp gain stage. Phase inverters, cathode followers and reverb drivers are the ones that are hard on tubes.
     
  7. Buckaroo

    Buckaroo Tele-Meister

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    If you really want to hear the tone of the tube it should be deployed in your primary gain stage...so the signal from your amp input hits that tube first. IMO, that is how I assess the sonics of any new preamp tube.
     
  8. 50ShadesofOrange

    50ShadesofOrange Tele-Meister

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    See, now I’m learning something! If it’s not taking any more of a beating in V1 of the Vibro Champ than V2 of the Twin Reverb, plus given my current volume restrictions, where the VC gets *much* more playing time, this is starting to look like easy math.

    Thank you.
     
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  9. MuddyWolf

    MuddyWolf Tele-Meister

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    I would have a display case made and vacuum pack the tube in it. Then I would build a little alcove in my room with a cool pedestal with exactly 7 candles lit that shall never go out. Then I would put on a holy robe and 2 pointed tall hat and chant "Oooooh most groovy of tubes, please enlighten meeeee".


    Then I would throw all that stuff away and put the vintage 12ax7 in my 73 vibrochamp.
    Yeah that's what I'd do.
     
  10. Commodore 64

    Commodore 64 Friend of Leo's

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    My main advice? Don't drop it.
     
  11. DrPepper

    DrPepper Friend of Leo's Ad Free Member

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    Put it in the amp you play straight into....
     
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  12. TheDams

    TheDams Tele-Holic

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    they also had a company in France...
     
  13. DrPepper

    DrPepper Friend of Leo's Ad Free Member

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    Try it in both and let ears decide...
     
  14. archetype

    archetype Fiend of Leo's

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    Are we still talking about this? It takes 10 minutes to put it in either amp. Where's the report on how it sounds? :D
     
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  15. 50ShadesofOrange

    50ShadesofOrange Tele-Meister

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    That’s absurd.

    I merely genuflected.

    So my sister-in-law brought her kids over, so my daughter was briefly distracted. I got my first free time in months.

    I threw the tube in the V1 on the Vibro Champ. I ran out of time before I could A/B it with the JJ I had in there, but the heavens did not part. I mean, it sounded good, but I’m not sure it was a massive improvement.

    But now I know.

    Thanks for all you help, advice and ridicule!
     
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  16. Bartholomew3

    Bartholomew3 Friend of Leo's

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    I have a few vintage 12AX7 and 7025 tubes from being on the road in the Sixties. RCA, Telefunken, other no-name stuff from Russia that works pretty good.

    Have been trying those old tubes in a new 15 watt head and have the same conclusion - sound good, maybe better than the Asian stuff it came with, not a huge difference.

    Seems to make an improvement in tone - pretty much sounds the same after a couple of recording plug-ins or pedals.
     
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  17. theprofessor

    theprofessor Poster Extraordinaire

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    If you're able to give us any kind of description as to what you heard with the Mazda that was different from the JJ, I'd like to hear it. I've not had a Mazda 12ax7 before, and I'd very much like to know what the scoop is on their tonality. I'd guess bright and sharp, but that's just a guess.
     
  18. 50ShadesofOrange

    50ShadesofOrange Tele-Meister

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    The Mazda sounded nice. I’ve still got the stock Oxford in my Vibro Champ, so it started farting out before I could really push the tube. The cleans were kinda as you described, bright and sharp, as evidenced by the fact I most enjoyed the tones I was getting with the neck P-90 on a Les Paul Special (I also tried it with a couple Teles, a single-Lipstick 50s Silvertone and a 335).

    I’m terrible about picking out “scooped mids” and whatnot, but I know what sounds good to me. I suspect the darker Gibson neck pickup found a balance with the brightness the amp was delivering.

    And exactly as Batholomew3 stated, once I added a little reverb, the differences with the JJ 12AX7 (at probably a quarter of the cost) were negligible.

    I’ll mess with it some more when the opportunity presents itself. Perhaps the differences will stand out more when I can play the Mazda back to back with the JJ.

    The amp already sounded great with the JJ. But so goes the tone quest, where it’s really hard to leave well enough alone. I can easily see how these tubes can turn into quite the rabbit hole.
     
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  19. theprofessor

    theprofessor Poster Extraordinaire

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    Thanks for the response. Well as for the rabbit hole, that is very true. If it's one you like going down, and you have the money to explore it, it can be quite fun. But it's not for everybody!
     
  20. teleman1

    teleman1 Tele-Afflicted

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    For my layman explanation, when you get NOS/ANOS ttubes, don't expect the world. But, realize, there is no easy way to help your amps sound better. The NOS/ANOS I believe give anywhere from a 5% improvement to as much as 18% in overall tone. Could also make it darker or the opposite. The most magic I have heard is placing a real deal Mullard in most any Fender v1 and lots of things happen. Better tone & better 3d It is the one tube that does humiliate any modern production as far as I am concerned.
     
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