new member - GT question

Discussion in 'The Workbench' started by Pulsonic, Apr 2, 2020.

  1. Pulsonic

    Pulsonic New Member

    Joined:
    Mar 26, 2020
    Messages:
    2
    Likes Received:
    0
    hola all -

    wanted to introduce myself on the Tech page. lurker for many yrs. - hope to keep learning.

    anyone have experience on the old Groove Tubes EL34-R2 valve ? my set are inked w/ '6' on the bottom left label area, and like initials CBC or something on the right bottom label area.

    so, was biasing my 55LV w/ Eurotubes (cheap model) bias thing - and dropped/broke one of the GT's. am pissed - cause:

    * aren't these actually production =C= valves, just relabled ?
    * does anyone know a source for another '#6' inked replacement R2 valve ?
    * is the '6' just Aspen/Fender's matching code ?
    * does the Eurotubes cheapie probe require subtracting cathode measurement - confused on how that ET unit is actually constructed.

    have a stash of old glass, but found this pair on my bench somehow (may have come out of a new '06 Orange OR50 i traded out years ago) and liked the tone a bit in my '82 JCM800 50-watt (head converted) 4104 (2204 now).

    bummed out i let slip out of my hand. happened only once before with a Pinacle KT-66 clear glass many yrs. ago (f-ing pissed then) =\ - still haven't got over that. had several Pinnacles that were wonky/couldn't bias up.

    would love to find a match for the lost valve.

    enough for now - stay safe / P
     
  2. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    17,862
    Likes Received:
    11,902
    Location:
    Bio-Isolation Lock Down
    Welcome to the forum Pulsonic dude. :cheers:

    No
    Because groove tubes started selling tubes from China.
    All the Russian Groove tubes are reserved for Fender amplifiers now.

    I think you will have a tough time finding a match for the broken tube sorry.
     
  3. Geeze

    Geeze Well-Known Member

    Joined:
    Jul 25, 2015
    Messages:
    1,376
    Likes Received:
    2,303
    Location:
    Floating around TN in Marshall Heaven
    Welcome to posting on the Forum!

    I'd the usual NOS tube vendors - Doug's, KCA come to mind - ask them if they can 'match' your tube with something else as a last resort. I'd be wary of others until proven to be reputable in their measuring and marking.

    BTW I use a pair of DMM's - don't have to pull tubes - but you do get to play Operation! inside the amp guts. My amp guy turned me on to this guy from D Lab when I had an emergency bias the night before a show.

    Russ
     
  4. Pulsonic

    Pulsonic New Member

    Joined:
    Mar 26, 2020
    Messages:
    2
    Likes Received:
    0
    Thx guys - saw another d-lab video on something, hadn't seen this one gracias.

    Wonder if Mesa carries the old hotter graded RFT EL34s anymore. will ask.

    P
     

Share This Page

  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.
    Dismiss Notice