6L6 tubes from TAD - which one?

Discussion in 'Amps and Cabs [BG]' started by vbchaos, Feb 14, 2013.

  1. vbchaos


    Sep 5, 2011
    Groningen, The Netherlands
    Uncompensated endorsing user: fEARful
    Hi folks,

    my Traynor YBA 300 amp needs some new tubes. Although I have this amp for only a year now, two of the 6 pairs behave quite strange... looking at the BIAS in the back, usually the indicators start glowing yellow (HIGH) when playing, but these two pairs simply do nothing most of the time, sometimes indicates LOW...
    So to go short, replacing!!!
    I sorted out all the tubes I can get over here in the Netherlands. I need 6L6 tubes (or EL34, but I want 6L6 again) and after hours of reading I figured out that TubeAmpDoctor tubes will do best regarding what you get for the price. But, of course, they have two different types of tubes, which are:
    - 6L6GC STR
    - 6L6WGC STR

    It seems that adding a "W" costs around 10 Euros, so here's the thing: They say the WGC last longer and are "heavy duty" - but are they worth the 10 euros more?

    Does anyone have experience with these tubes?
  2. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    W is supposed to be code for military-spec tubes. At least it used to be. Lord knows if it makes a difference these days, though.
  3. Wondering why u think this means u need new tubes?
    My YBA300 the bias lights will usually stay off while in "active" mode, sometimes one or two pairs will show wandering to blue or yellow.
    Just adjust & continue.
    Unless u can't get a pair to show "normal" (no light ).
    Yes? No? Why? :confused:
  4. vbchaos


    Sep 5, 2011
    Groningen, The Netherlands
    Uncompensated endorsing user: fEARful
    Because all tube pairs did behave totally the same, until some stupid stagehand did not handle my amp with care. The day after, both tube pairs did need some massive re-tuning of the BIAS and both are now behaving like mentioned above, and I do not trust it. Last weekend gig, the amp failed to start up during sound check (stayed in PROTECT mode). Off - 5 minutes waiting - ON did the trick, but I simply do not trust these two pairs anymore.
    Sometimes one of the pairs stays blue for a long time, then I re-adjust, and a couple of minutes later is says HIGHIGHIGH. So, it's quite strange...

    Your BIAS LEDs stay off? I drive my master knob all the way, so maybe thats why my LEDs are yellow as soon as I play. But, they all should do (because they all did). As long is my bass is silenced, the LEDs stay off of course.
  5. Ahh, gotcha.:thumbup: goodluck with it, & let us know (either here or the YBA300 thread) how it goes, if u can.
  6. jnewmark

    jnewmark Just wanna play the groove. Supporting Member

    Aug 31, 2006
    Stax 1966
    Play guitar.
    I use Winged C 6l6's in my Music Man 150. They take higher plate voltage, if that is a concern, and really beefed up the sound, as opposed to JJ's. I got them from tctubes.com
  7. The "W" stands for wide bottle. WGC are shorter and wider than the GC. Not worth the additional cost unless you have space troubles or want the look. Here in the US they are the same price ($22.75 each w/o matching). If you can't muster the cash for Winged "C"s then just go with the 6L6GC STR.
  8. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Hmmm...see what I mean? W used to mean mil-spec, now it means wide-bottle, though I'm sure for some companies it still means mil-spec, even though it's highly doubtful anyone builds mil-spec tubes these days. Whatever happened to standardization?
  9. Mil spec tubes were numbered Jimmy preceeded by JAN, "W" has always been for wide bottle.
  10. Correction non-critical applications used standard alpha-numeric but would always have the JAN (Joint Army Navy)
  11. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    You scared me for a second, Jon! After your first post I started imagining I could be wrong, and a cold chill came over me ;)
  12. Sorry you were, "G", "C", "W" and "B" were bottle styles and had nothing to do with mil spec or ruggedized "industrial" versions ;)
  13. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    So the mil-spec 6146w's aren't denoted as mil-spec by the W? Because my tube guy said they were mil-spec 6146b's.
  14. Nope only if "JAN" is part of the part number. The W was a revision with a wider bottle for better heat dissipation. They were RF transmitter tubes, 6146 being an "industrial" tube type.
  15. Interesting. :thumbup:
    So what's "STR" stand for?

    Any other letters & numbers u can let us know about?
    In regards to tubes;)
  16. Don't remember off hand what "STR" stands for as that is a relatively new item. In alpha-numeric designations the first number is the heater voltage (6- 6volts, 12- 12volts. 35-35volts, 50-50volts) US used these as well as four number for "industrial types. Europe used letters first (EL, ECC) for similar or exact to some US types. Suffix on the alpha-numeric was used for optional ratings/revisions/envelope types, industrial types fallowed suit on suffix.
  17. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    As far as I know STR usually denotes a "custom" design. Rebranders use that term, it's short for "special tube request" or something like that. Mesa, Groove Tubes, Ruby, Fender, TAD, etc, who all purchase their tubes from big manufacturers (usually the same plants in China or Russia) use the STR designation to indicate it's their proprietary specs or QC ranges are used in the design.
  18. wcriley


    Apr 5, 2010
    Western PA
    If memory serves (which at my age, often doesn't) Leo Fender had STR tubes made for his amps. I've been told they were somehow optimized to hang upside down.
  19. They are both rebadged chinese valves, I'd recommend the winged c's personally. The more expensive of the shuguang ones are nice to
  20. GlennW


    Sep 6, 2006
    I'm unfamiliar with TAD stuff, but STR-387 6L6GC's made by Sylvania are de Schiz imo. They have double getters on top and sound better than the rest I tried, including SED =C= and RCA black plates.

    Often they're labeled Fender, Peavey, MESA.

    So, maybe TAD is using a STR designation as a marketing ploy to increase sales? Just a guess.

    BEWARE: I just noticed Ruby and other brands of STR-387s with different getters...tsk, tsk, tsk.
    The ones with the DOUBLE GETTERS BY SYLVANIA are the ones.

    All imo...

    Edit: pics courtesy of ebay

    I hope I was nice enough about that.