Dumping JJ's due to thinner contact pins. WTB tubes and which brands?

Discussion in 'Amps and Cabs' started by 5150, May 20, 2015.

  1. 5150

    5150 Member

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    I have had multiple issues with JJ preamp and power amp tubes causing my amp to cut out or stop making sounds at all, due to JJ's insistence on using thinner-than-standard contact pins on their tubes. Has anyone else experienced this? I'm in the market for matched sets 6L6GC's, as well as 5 12ax7's pre-amp tubes. I have no idea what or where to buy. Tube Amp Doctor? AmplifiedParts? Should I go for Mullards? Winged-C Svetlana? GrooveTubes? New? NOS? Any thoughts or recommendations for a Peavey 5150 combo?
     
  2. Blue Strat

    Blue Strat Member

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    Yeah, I don't know what's up with JJ and their pin diameters. You'd think that would be the EASY part of tube manufacturing!
     
  3. StratStringSlinger

    StratStringSlinger Member

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    I hadn't notice any problems with my amps and I run a lot of JJ's. I will take note though. For the OP, could you maybe try tensioning the the tube sockets?
     
  4. Dr. Tweedbucket

    Dr. Tweedbucket Deluxe model available !!!11

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    The only thinner pins are on the KT77s, but I haven't bought any for a few years :huh
     
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  5. Trout

    Trout Member

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    I just retired a pair of the KT-77s from the original thin pin batch, never once had a problem with it.
    These things had a bazillion miles on the road bouncing around in the back of the band trailer.
    The sockets were Belton and they fit just fine in those.
    I have never seen a 12a_7 JJ with excessively thin pins.

    I think it would be wise to check the sockets though.
     
  6. Figaro

    Figaro Supporting Member

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    Are Tung Sol preamp tube pins the same size?
     
  7. swiveltung

    swiveltung Member

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    I thought JJ got rid of thin pins many years ago? Are yours ancient?
     
  8. tazzboy

    tazzboy Supporting Member

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    Yeah I don't have that problem.
     
  9. oldhousescott

    oldhousescott Silver Supporting Member

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    I like the Sovtek 6L6WXT+. It's a solid contender at a reasonable price. For preamp tubes, you may want to roll a few to see what you like, although I'm not sure how much difference you'll hear in the 5150 circuit. I like the reissue Tung-Sol for general purpose use, although the EHX and Shuguang are pretty decent too. At one time, there was a potential issue using the russian tubes in cathode follower positions. Mike or someone more knowledgeable than me would have to chime in to state if that's still the case.
     
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  10. RussB

    RussB low rent hobbyist Silver Supporting Member

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    I remember when JJ's had big blobs of solder on the tips of their power tubes which would stretch out the sockets. I would take an x-acto knife and whittle away the excess solder. The only thing you can count on with JJ tubes is inconsistency
     
  11. 5150

    5150 Member

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    What do you consider as ancient? I bought a bunch of sets back in 2009, 2010? Don't remember. All i know is all were brand new from eurotubes.
     
  12. 5150

    5150 Member

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    When did JJ change to thicker pins? I compared mine to a set of groove tubes and the difference was obvious with the naked eye
     
  13. 5150

    5150 Member

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    No blobs of solder here ever. Have 6l6, ecc832, el84, 12ax7 all jj's.
     
  14. bluesoul

    bluesoul Silver Supporting Member

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    The JJ El84's in one of my heads caused problems due to thin pins...Sovteks have thicker pins and fixed that issue...so yeah I see where you are coming from.
     
  15. DaveKS

    DaveKS Member

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    It's a quality control issue, I've seen it 1st hand, and it rears it's head on occasions. I've even measured with a caliper different sized pins on the same f'n tube. As Blue Strat pointed out, seems like that would be one of easiest and simplest manufacturing processes in making a tube to do consistently correct. But yet they fail at it over and over again.
     
  16. pine

    pine Silver Supporting Member

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    I have had issues with JJ tubes having pins that were too thin as well.
     
  17. Blue Strat

    Blue Strat Member

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    If memory serves,~10 years ago they were producing OCTAL tubes with pins that were too LARGE in diameter. Anything you plugged in afterwards would fall out of the sockets. Maybe this is their "fix".
     
  18. swiveltung

    swiveltung Member

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    OK, let's put this myth to rest, at least regarding octals. I don't use JJ 9 pin pre tubes so cant comment on that. I measured a bunch of octal tubes with digital calipers, at least 3 of each brand:
    6v6's:
    GE .089/.090
    RCA .086/.088
    Tung Sol: .089/.091
    JJ: .088/.089

    6L6:
    GT .088/.090
    TAD .091/.092
    Sylvania .087/.089
    Winged C: .088/.089
    RCA: .088/.089

    Import 5AR4 Rectifiers:
    JJ .089/.090
    EH .088/.090
     
    Last edited: May 21, 2015
  19. Jon Silberman

    Jon Silberman 10Q Jerry & Dickey Gold Supporting Member

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    I've never liked the various JJ's I've tried over the years. I can't be specific as to why, I've just always found alternatives I thought sounded better and now no longer consider JJs at all.
     
  20. Blue Strat

    Blue Strat Member

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    Must be related to various production runs. Few things in life are 100%, always.
     

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