Mechanical Rattles in New Prod. Tubes

Discussion in 'Amp Tech Center' started by ocduff, Sep 1, 2017.

  1. ocduff

    ocduff TDPRI Member

    Posts:
    87
    Joined:
    Nov 17, 2003
    Location:
    USA
    This may be more of a rant but this has me so dissapointed. I purchase about a dozen power tubes a year and, while this is anecdotal evidence, I don't believe it's entirely coincidental that nearly HALF of all new power tubes - factory matched and tested, reseller matched and tested - have mechanical noises, as in loose rattling components inside of the tube - which about 2/3 of the time translates into a microphonic rattle.

    Now - I know good NOS tubes - but for amps going out the door I'm constantly stuck with rattling tubes - my supplier makes good on them but often the replacements have the same issue. In the end I end up with a bunch of tubes I can't use.

    I don't expect the factory to check for mechincal noise - they clearly send any tube out the door that "functions". So they aren't going to help us.

    Is there a reseller (even if they charge $3 more per tube) that simply holds a tube up to their ear, gives it a shake, and if they hear a rattle, trash it?

    I'm just at a loss - I've experienced this with JJ a lot (as I use them most as I like their 6L6 tone) and TAD as well, but never with the Sovtek/EH (so I am going to try and go with them more).

    But seriously - are there resellers actively testing power tubes for microphonics and actually burning in tubes for 24 hours before matching (to weed out bad tubes and help them keep their bias numbers more?)

    And I mean a reseller who I NEVER have to call up and ask for more tubes and box the old ones back up or even keep them (when they are trash).

    Obviously the way to turn a profit on tubes is just to hope no one complains and send them all out.

    But I have new power tubes with three dang silicon rings on them that still rattle and life is too short to be dealing with rattling noises.

    Anyone with me here? If some of you have no idea what I'm talking about, where are you getting your tubes?
     
    alnicopu likes this.
  2. peteb

    peteb Friend of Leo's

    Posts:
    3,921
    Joined:
    Apr 25, 2003
    Location:
    Cascadia
    I don't buy many tubes, but one out of two pairs that I've bought in the last couple of years had the mechanical rattle.

    It is a pair of new tungsol 6v6s. As far as I know, the new tungsol is just a EH/Sovtek/Reflektor tube.



    The mechanical rattle seems to have disappeared, or at least abated, it doesn't really bother me any more.


    I am more un pleased that the matched pair drifted and would now be considered an unmatched pair, 20% difference.
     
  3. JD0x0

    JD0x0 Poster Extraordinaire

    Age:
    29
    Posts:
    5,865
    Joined:
    Feb 22, 2009
    Location:
    New York
    Combos?

    I use Chinese shuguang power tubes, and dont seem to have any issues, but I also dont have many combo amps. I'm generally not a fan of JJ's, personally. TAD are apparently just rebranded and (supposedly) tested tubes. Plenty of retailers offer 24 hour burn in and matching as options.
     
  4. ocduff

    ocduff TDPRI Member

    Posts:
    87
    Joined:
    Nov 17, 2003
    Location:
    USA
    Thanks guys - yes this rattling would mostly apply to combo amps.

    And I would absolutely pay a premium for tubes that are tested for rattles, are burnt in for 24 hours and then matched.

    I've had "factory matched" Tung Sols drift apart 9ma within several hours of use.

    Lots of rebranding - as far as I know there are only three factories making tubes - Shuguang in China (TAD), JJ in Slovakia, and New Sensor in Russia (Sovtek, EH, TS, Mullard).

    It seems like Fender uses the Sovtek 6L6WXT in most of its amps that go out the door - to me this says something, not about tone but in reliability and amps not having warranty work done for tubes or tube microphonics.

    I've had little issue whatsoever with pre-amp tubes. It's all been with power tubes.
     
  5. Silverface

    Silverface Poster Extraordinaire Ad Free Member

    Age:
    67
    Posts:
    9,159
    Joined:
    Mar 2, 2003
    Location:
    Lawndale CA
    Interesting. One unrelated question - that's an unusually high number of tubes for personal use - I know touring pros who go through that many but other than them and techs I know nobody that goes through power tubes like that or has any reason to. One person can't use that many up. Are you working on amps and are clients complaining? If so is it a small group of clients playing one style, or ?? It'd be enlightening to know how the tubes are being used.

    I do work on amps and go though far more. I haven't had problems with more than about one tube out of 40 or 50, and never both of a matched pair - and not a single JJ power tube. Drift under 5ma I consider reasonable and in-spec; but again, I've ever had new JJ's or Tung Sols go out of spec. I have had several pairs of GT 6L6GE's go way out & won't install them any longer; also matching issues with 6L6C's, another I won't install.

    But while I have had a few rattles - very few - with EH/Sovtek tubes (a couple EL84's I recall, a few 5881's and at least one 6L6WXT) but just not any sort of "regular" problem that anyone has ever reported - and absolutely none in my own amps.

    Again, some details regarding how the tubes are used might be helpful. Because, at least to me, it seems an isolated issue.
     
  6. Silverface

    Silverface Poster Extraordinaire Ad Free Member

    Age:
    67
    Posts:
    9,159
    Joined:
    Mar 2, 2003
    Location:
    Lawndale CA
    Fender owns Groove Tubes. For the most part tubes are installed and biased for reliability, not tone. New amps are always biased on the cold side and sound much better if taken right to a tech for a rebias.

    FWIW the tube manufacturers listed are the "big three" and make most of the guitar amp tubes commonly bought new - but there are another dozen just specializing in the hi-fi market (which sometimes have products show up in the guitar market, especially preamp tubes) plus a smattering of industrial manufacturers.
     
    Last edited: Sep 2, 2017
  7. alnicopu

    alnicopu Friend of Leo's

    Posts:
    3,806
    Joined:
    Oct 3, 2009
    Location:
    The city
    Dont feel bad. I bought a set of matched Jan Philips 6v6 nos tubes, from a reputable reseller, and one did that after about a month. Ive had a rash of J.J.'s do that right out of the box. Ive had so many J.J. Ecc803s preamps that sounded so bad I quit buying them altogether.
     
  8. ocduff

    ocduff TDPRI Member

    Posts:
    87
    Joined:
    Nov 17, 2003
    Location:
    USA
    I must just have bad luck. I use a lot of tubes - okay? :)

    I've heard many others complain of similar issues but perhaps it's over reported. In my case I literally think 1/3 of the dozen tubes I've bought in the past year have had the mechanical rattle. That doesn't always translate to a noise in the amp but it's not confidence inspiring.

    Not much more I can add - I just don't find tube sellers or resellers are truly weeding stuff out.

    NOS I have zero issues with. And it's primarily TAD and JJ power tubes ive had the issue with but only because I use them the most.
     
  9. alnicopu

    alnicopu Friend of Leo's

    Posts:
    3,806
    Joined:
    Oct 3, 2009
    Location:
    The city
    Diddo. J.J.'s are way overhyped per my experience. Never used TAD but, good to know.
     
  10. Silverface

    Silverface Poster Extraordinaire Ad Free Member

    Age:
    67
    Posts:
    9,159
    Joined:
    Mar 2, 2003
    Location:
    Lawndale CA
    Again - are these all in your own amps? If so - why? It'd take a huge amount of effort for one player to wear out a dozen power tubes in several years.

    And where were they purchased - specifically?

    These answers could shed some light on the problem, because the whole situation is very unclear.
     
  11. peteb

    peteb Friend of Leo's

    Posts:
    3,921
    Joined:
    Apr 25, 2003
    Location:
    Cascadia
    From their site:

    ABOUT TAD PREMIUM TUBES:


    TAD does all TAD Tube quality control processing in-house under strict control of our technical staff. Our techs which are also musicians and guitar players, developed and constructed our custom tube testing systems and aging rigs to run tubes in real amplifier circuits and operation conditions.

    For TAD, real tube quality control is way more than just a simple test. Before a TAD Tube gets accepted at all we perform extensive sample evaluation testing for consistency, power test, shock resistance test, soak test (long term operation at full power) and of course a musical test in known amplifiers to learn about its sound character in different styles. The main tests are made after a propper pre-aging to stabilize the cathode emission. While most tube test equipment does work at 250V as a maximum we built our test rig to operate at voltages of 360 to 600V depending on the tubes being tested. Every TAD Tube is tested by our qualified staff. Each pentode is inspected,tapped while operating and listened for noise floor, hum and odd noise.

    Finally measured for a set of parameters and matched by Ia (PC) and Gm (TC). We do test batches of 400 to 500 pieces per run to allow tightest tolerances of typically 0.5mA for PC. All TAD Tubes and boxes get labeled with the PC and TC test results and a unique serial number to identify every tube we’ve ever tested. We permanently verify and monitor selected and matched TAD Tubes by using them every day in our own amp service department and in the TAD Amp Kits we assemble. This is the most complete quality control system we can imagine.
    All done in-house at TAD in Germany
     
    ocduff likes this.
  12. peteb

    peteb Friend of Leo's

    Posts:
    3,921
    Joined:
    Apr 25, 2003
    Location:
    Cascadia
    Based on the above, I would think they would accept for return any tube that was thought to not sound right.


    What other vendors would offer this service?


    Groove tubes?


    Any others?



    What about NOS tube dealers? Any of them accept returns?
     
    ocduff likes this.
  13. MrGibbly

    MrGibbly Tele-Afflicted

    Posts:
    1,203
    Joined:
    Apr 19, 2014
    Location:
    SATX
    Key words here may be "sample evaluation". This might indicate that they select a sample set of incoming tubes and test those tubes with this full, extensive test set. How big is the sample? Is it done on every delivery of tubes, every manufacturing lot, every time a new model is introduced into the lineup? I've always had positive experiences but I haven't gone through all that many power tubes in 20+ years of playing.
     
    ocduff likes this.
  14. radiocaster

    radiocaster Poster Extraordinaire

    Posts:
    5,116
    Joined:
    Aug 18, 2015
    Location:
    europe
    So how is your amp biased?
     
    ocduff likes this.
  15. peteb

    peteb Friend of Leo's

    Posts:
    3,921
    Joined:
    Apr 25, 2003
    Location:
    Cascadia
    It's hard to tell exactly what they mean,

    But the key thing is that they sound like they stand behind their product.



     
    ocduff likes this.
  16. ocduff

    ocduff TDPRI Member

    Posts:
    87
    Joined:
    Nov 17, 2003
    Location:
    USA
    1. Not all for my use. Amps I build or fix or for my own amps.

    2. Mojotone (who has sent replacements which may or may not have been any better).

    Tubes with issues have JJ 6L6GC which I actually really like the sound of - bold, a bit of furr on the tone, deep lows, good mids and clear highs.

    On TAD Ive had mechanical noises in the tubes but no microphonics.

    And if TAD tubes are factory matched they seem not to drift. So there may be merit to what they are stating they do to test them.

    It would be nice if there was a premium tube out there - rugged, long lasting, supremely toneful, and tested stringently. I know some of these makers have $65 versions of their same tubes - maybe that is the answer and what truly good performance costs.

    And I've had SED Winged C's that were nothing but rattles and microphonics.

    Electro Harmonix and Sovtek as well as Tung Sol reissue (all same company) I've had no such experiences.
     
    peteb likes this.
  17. alnicopu

    alnicopu Friend of Leo's

    Posts:
    3,806
    Joined:
    Oct 3, 2009
    Location:
    The city
    Funny how you never hear anyone say "my inexpensive Chinese tubes failed". I got my Grandmothers Sano amp from the early 70's when she passed, she was an accordian teacher. That thing had 4 Amperex, Bugle Boy 12ax7's in it and 4 mullard 7189's. Swapped out the sylvanias in my princeton reverb, then my champ. No difference at all in tone. Couldnt get 500.00 for it on CL. Then, I deleted it, waited about a month and advertised it with the bugle boys and mullards in there and got 800.00 within a week. Sometimes it's all in the perception.
     
  18. Silverface

    Silverface Poster Extraordinaire Ad Free Member

    Age:
    67
    Posts:
    9,159
    Joined:
    Mar 2, 2003
    Location:
    Lawndale CA
    "My inexpensive Chines tubes failed". :lol:

    I refuse to install Chinese power tubes. Too many players have reported very poor durability. They often sound fine but wear out in a fraction of the time of virtually every other. Preamp tubes are not extremely long-lived either but not terribly bad.
     
  19. cap47

    cap47 Tele-Holic

    Posts:
    529
    Joined:
    Jul 27, 2014
    Location:
    bushnell, fl
    In order for them to know the PC and TC numbers to mark on the tubes they would have to test each and every tube !
     
  20. cap47

    cap47 Tele-Holic

    Posts:
    529
    Joined:
    Jul 27, 2014
    Location:
    bushnell, fl
    My only failed TAD power tube had a ripple in the glass and that became a weak point and cracked and let all the mojo out of the tube ! :cry: My next tube fail was after about 4 years use of 6L6EH which was actually WXT+ with the EH printing. I bought 6l6WXT+ and they were identical construction and sounded the the same as the EH.
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.