GT 12AX7M is "ticking" ....are these all bad tubes ?

Discussion in 'Amps and Cabs' started by JohnK24, May 13, 2005.


  1. JohnK24

    JohnK24 Supporting Member

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    This is my second one. The first one I received instantly caused my amp (Blues Jr.) to make a loud cycling hiss...it went back. This replacement was fine for three or four days of easy use (1 hour a day maybe), then the ticking or popping noise started. It's a low volume sound, doesn't get louder with the volume increased, but it's annoying as heck. When I move the GT 12AX7M to the V2 slot and put my older JJ into V1 the ticking goes away.

    I'm done with GT, at $24 for one tube, this is really poor quality control. I will say the tube had a nice, warm and thick tone, definitely nicer than the JJ tube. I'll try another long plate tube sometime, they do have a nicer tone, imho.

    JK
     
  2. Matt Gordon

    Matt Gordon Senior Member

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    Yeah, thats a bad one. I had my fave 9th gen V1 go funky like that (after a massive fuzz box workout) :D and replaced it with a EH 12AX7. Everyone should have about ten spare EH, because they sound pretty good in most amps, and are really inexpensive.
     
  3. Curt

    Curt Member

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    Call Bob at Eurotubes and have him send you out a pair of the new JJ803S's for V1 and V2. You'll be a happy camper.
     
  4. RussB

    RussB low rent hobbyist Silver Supporting Member

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    4 out of 5 GT-M's went nutzo on me, 2 did the "motorboat" thing, one was very microphonic, and the other went berzerk!

    4 out of 5 are very bad odds...

    I have been waiting for the last one's replacement since March 2nd. GT claims to have none in stock :mad:
     
  5. aleclee

    aleclee TGP Tech Wrangler Staff Member

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    I've used 4-5 of the GT-M tubes with great results. That said, Lord Valve has taken to checking 'em himself to ensure that the ones that reach customers are good. Not a good sign for a product coming from a company that supposedly does rigorous testing themselves.

    The new Tung Sol tubes are supposed to be good in high gain amps. I have one in my Two Rock but will proably replace it with an NOS Raytheon when I A/B 'em tomorrow.

    In high gain applications, I prefer the 9th gen Chinese to either the EH or JJ's which are just okay IMO.
     
  6. Buckeyedog

    Buckeyedog Supporting Member

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    Yeah, I have 3 of the "M's" and they make some funny noises too. Not real happy with them. I'm done with GT as well. I'm curious to try those JJ803S's.
     
  7. hipfan

    hipfan Member

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    I've had about 3 or 4 of the GT M's go all funky on me. I had the ticking, motorboating, and hissing with different tubes. The tone is OK IMO, but not worth rolling the dice. For the same price ballpark, you can get used-but-good Mullards or Amperex, or NOS RFT's or Tungsram, and get subjectively better tone than the M's.

    That being said, the new JJ 803's sound really nice. I find them balanced sounding and smooth, with nice sized output and good gain. Make sure you get them from a retailer that thoroughly tests them though. From what I hear, they've been very inconsistent from the manufacturer. I got mine from Doug's tubes, and they sound great, with no mechanical problems at all thus far.
     
  8. big mike

    big mike Fixed Bias Moderator Staff Member

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    Hmm. No problem with mine. But also purchased from Lord Valve.
     
  9. gearo999

    gearo999 Member

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    I had two GT M's go bad. They sound good but they don't last.
     
  10. hasserl

    hasserl Member

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    I've had a couple go bad on me, and I've run across about four others on amps I've worked on that were noisy.

    They sound good if they aren't microphonic or hissy, but the failure rate of the ones I've run across is very high. I'm not buying any more until they correct it.
     
  11. John Bell

    John Bell Supporting Member

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    I've got two I bought from Guitar Center about a month ago.Both are worthless.Low output along with weird noises from both.50 bucks down the toilet as far as I'm concerned.Personally I think GT should give me a refund on these.

    Tried a set in my previous amp before trying it out first.I dumped the amp a month later.Now I think the problem was the tubes.

    At this point all Groove Tubes have been placed on my "do not buy" list.
     
  12. outtahear

    outtahear Supporting Member

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    AAaaaannnnnnddd .....where is Myles now??:confused:
     
  13. GuitarNorton

    GuitarNorton Member

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    Bumping for those folks who may have missed it!:D
     
  14. Igneous

    Igneous Supporting Member

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    Ive had three, theyve all frihggin crapped out on me. Mica spacers coming apart. everything. I knew it was too good to be true. Plus- they are very low gain. Very decieving

    I went back to switching it uyp with jj's. they have a bit more gain and are darker but reliable. Ive only had one jj go bad out of like 10. want to try the803s now too.

    Anyone want to buy a couple of hand selected gtax7m's? hehe
    They make great target practce if you have a BB gun.:rolleyes:
     
  15. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    I hate to jump on the hit parade here, but I have had only one good tube out of 6 myself. I just got three more from my amp tech to try out. All of the same problems the rest of you have experienced: high shriek, motorboat tone, tube rattle, etc.

    I'm pretty picky about my tubes, who isn't right? :) but this has been a real exercise in frustration. At the LA Amp Show, I tried to buttonhole Aspen, but he was busy, so I handed my card to the sales guy there, and said I have four or five bad tubes, and I'd be happy to drive up to GT to swap them for good tubes.

    It's been a week and no one has called me yet. Time to email Aspen directly to get this taken care of, I guess.

    I'll be trying out the other three brand new, still sealed in their boxes, GT12AX7M's later today, and report back.

    The JJ EC803S tubes are nice, not quite as much gain as the Sovtek LPS (my current favorite production preamp tube), but very nice tone. I got mine from Bob @ Eurotubes, he's a good guy to deal with.
     
  16. hogy

    hogy Member

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    We sent better than 90% back because of sputtering, hissing, hum, etc. Groove Tubes said they tested all we sent back and there was nothing wrong with them. They think it's our amps.
    I felt pretty unhappy, not only were the tubes worthless (not a small sample, and from different batches), I had to listen to the "GT engineers" tell me I was imagining it all.
    That's hard to listen to when you just sent a brand new amp to an important recording session to have the GT tubes crap out in the middle of recording.

    Myles made a lot of promises and at one time admitted on the phone that our returned tubes did indeed show problems on his personal, super sophisticated testing equipment, but unfortunately, GT uses different equipment to screen, and it doesn't detect the problem.

    I asked to buy tubes screened on the better equipment, but alas, that was too much trouble.

    Hogy
     
  17. bluessyndicate

    bluessyndicate Supporting Member

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    I'm having fun with Jan Phillips 12ax7's and am hooked on those now! fyi

    (I gotta tell someone, i'm telling everyone!)
     
  18. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    My experience has been similar to yours, Hogy. One good tube out of six. I have three more downstairs I'm testing this afternoon. They all seem to check out OK on my tube tester (Hickok 6000A) but if they motorboat in my test amp, then they're worthless.

    And to be honest, I really don't think that until you put the tube in an amp, that it makes a damn bit of difference what it did on the tester.

    Last time I checked, I played a tube amp live...not my tube tester.

    I realize this may be a little harsh, but.... hey, they're no good, & I just want some good ones, otherwise...JJ, Sovtek, etc. will get my orders.
     
  19. RussB

    RussB low rent hobbyist Silver Supporting Member

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    and one more time for all who missed these the first time around...

    here's a GT-M, a Mullard, and a Brimar. Dig those sloppy mica's in the GT-M. Myles braged about the long delay times getting the tube to retailers, because "they had to get the mica's right" I call BS!

    [​IMG]

    Here's the five I have/had. Four went bad after <20 hours time each. One tube is in limbo since 3-3-05, because GT claims to be out of stock!

    [​IMG]
     
  20. John Bell

    John Bell Supporting Member

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    I deleted my original post because I though it may have been over the top.The fact still stands that I have 2 GT 12ax7m's that are worthless.46 bucks from Guitar Center and they won't give me a refund or store credit.

    I'll buy a Line 6 before I buy another Groove Tube.
     

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