NOS tubes for Fender Vibro Champ

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by CNOTE, Oct 16, 2005.

  1. CNOTE

    CNOTE Member

    Messages:
    280
    Joined:
    Jul 7, 2005
    Location:
    Sugar Land, Tx
    Replacing my tubes in my 64 BF Fender Vibro Champ. Current tubes are:

    2 GT 12AX7s

    1 Slyvania 6V6GT

    1 RCA 5Y3GT

    I'm thinking about going with:

    2 Telefunkens for the 12 AX7s

    6V6GT ???? Not sure.

    5Y3GT ???? Not Sure.

    The amp is in great shape with a new Weber 8 Sig Alnico Speaker.

    I'm moving it back into my music room from my 12 year old son's room because I picked up a Fender Blues Junior for him.

    What would you recommend for the Tubes in this amp ?

    Thanks in advance.
     
  2. TheAmpNerd

    TheAmpNerd Member

    Messages:
    1,062
    Joined:
    Sep 23, 2004
    Location:
    Tejas
    How does it sound now?
    If you are going NOS, the clear glass RCA 6V6 is the
    standard. The JJ 6V6 is a fine sounding new prod tube.
    The folks in the Czec republic are really making some
    fine sounding and hardy tubes!

    If the RCA 5Y3 is good, stick with it.
    Sylvania made a great little 5y3 too.

    Teles for the 12AX7s are fine, don't rule out
    the RCA, GE, Sylvanias either. All are find sounding
    tubes.
     
  3. Blue Strat

    Blue Strat Member

    Messages:
    30,023
    Joined:
    Aug 2, 2002
    Location:
    Sterling, VA (not far from Washington DC)
    While you're thinking about Telefunken 12AX7s, do you realize that you'll be spending more that $100 each?

    Honestly, Telefunkens are great tubes but aren't as revered by guitar players as a lot of other 12AX7s. Why? Because Telefunken was one of the few companies who "got it right"! Huh? No one was developing tubes for guitar amps...too small a market. The goal was to produce a very clean, high fidelity device and Telefunken did this the best of anyone. This is also why relatively few guitar players like their 12AX7s (trust me, I've shipped close to 11,000 tube orders and speak with guitar players daily).

    Consider RCAs, GEs and Tungsrams which are all half, or less, the price of Telefunkens.
     
  4. CNOTE

    CNOTE Member

    Messages:
    280
    Joined:
    Jul 7, 2005
    Location:
    Sugar Land, Tx
    Amp Nerd and Blue Strat:

    Thankyou for your advise on the tube selection for the Fender Champ. I was hoping to hear from both of you.

    I read all your responses here on the GP. Continually, I am amazed at your precise and concise analysis to the myriad of different questions that can arise with all the fine amplifiers out there.

    This is a perfect example of why they call this The Experts Forum. Anyone with a simple question regarding amps can recieve first rate,top notch, top shelf information from pros like yourselves,(If one is willing to listen).:dude

    You made a very good point on the telefunkens in regards to the market size and quality of tube production when they were produced.

    Mike, I will be E-mailing you at KCA today for some new tubes.

    Gracias
     
  5. RussB

    RussB low rent hobbyist Silver Supporting Member

    Messages:
    11,042
    Joined:
    Jul 3, 2004
    Location:
    CT
    I wouldn't want to spend big buck on the trem oscillator tube myself...a cheapie will work out just fine.
     
  6. CNOTE

    CNOTE Member

    Messages:
    280
    Joined:
    Jul 7, 2005
    Location:
    Sugar Land, Tx
    RussB

    Perfecto. Your exactly right on that one.

    I'm even thinking about getting a mod to adapt the trem oscillator tube to become part of the gain chain. I think that can be done if I'm not mistaken.

    Gracias
     
  7. CNOTE

    CNOTE Member

    Messages:
    280
    Joined:
    Jul 7, 2005
    Location:
    Sugar Land, Tx
    I just ordered the :

    RCA 12AX7As

    Mazda 5Y3GB

    Macaroni 6V6G

    Thanks for the Help Guys:)
     
  8. TheAmpNerd

    TheAmpNerd Member

    Messages:
    1,062
    Joined:
    Sep 23, 2004
    Location:
    Tejas
    CNOTE, you are too kind.
    I am just but one. There are many more qualified that I.
    I just happen to like to read and write. So I read a lot
    and lucly took a typing class 30 years ago so it is pretty
    easy for me to knock out some words now and again.

    Plus, with all the big brains here I learn a lot too. It is
    kinda like music, there is always more and something
    new to learn.

    Enjoy and have fun on your own personal tone quest.

    That is what it is all about.

     
  9. Reeek

    Reeek Member

    Messages:
    1,208
    Joined:
    Feb 1, 2005
    Location:
    Reno, NV
    Will the Marconi 6V6G fit in the BF Vibro Champ without hitting the speaker?

    I have a few pairs of them and although they are the bomb tone wise, they are a big bottle tube. Just wanted you to make sure is all

    Good luck!
     
  10. CNOTE

    CNOTE Member

    Messages:
    280
    Joined:
    Jul 7, 2005
    Location:
    Sugar Land, Tx
    Reek

    Thanks for the heads up on the size of the Marconi for the 6V6 GT position. I measured from plate to the speaker bell and the clearance is not enough for the Marconi to fit since I put in the Weber 8 Sig Alnico.

    I called Mike at KCA and were changing to a Brimar.I just caught him before he was mailing the tubes!

    Right on spot... Thanks Reek
     
  11. Reeek

    Reeek Member

    Messages:
    1,208
    Joined:
    Feb 1, 2005
    Location:
    Reno, NV
    No problem CNOTE . . . Been there, done that :)
     
  12. Blue Strat

    Blue Strat Member

    Messages:
    30,023
    Joined:
    Aug 2, 2002
    Location:
    Sterling, VA (not far from Washington DC)


    Damn those Weber speakers! :D The tube would've been fine with the stock speaker.
     
  13. Reeek

    Reeek Member

    Messages:
    1,208
    Joined:
    Feb 1, 2005
    Location:
    Reno, NV
    Mike,

    I have one in my Vibro Champ so that's why I was cognizant of it ;)
     
  14. bbarnard

    bbarnard Member

    Messages:
    3,632
    Joined:
    Sep 17, 2003
    Location:
    FL


    You won't be disappointed in the Brimar. I have two in my Super Champ and they have a lovely smooth yet smokey tone to them.
     
  15. Reeek

    Reeek Member

    Messages:
    1,208
    Joined:
    Feb 1, 2005
    Location:
    Reno, NV
    I own some of the Brimars from Mike too. "You'll be just fine!" :D
     
  16. CNOTE

    CNOTE Member

    Messages:
    280
    Joined:
    Jul 7, 2005
    Location:
    Sugar Land, Tx
    Reeek and bbarnard

    MY MENTAL VISION IS AT EASE NOW... THANKS GUYS:D

    Reeek - your amp collection is cool! And "The Two Amigos" son muchisimo magnifico.
     
  17. RL in Fla

    RL in Fla Member

    Messages:
    3,198
    Joined:
    Feb 2, 2003
    Location:
    Future Cleanup Site
    Another +1 . I like 'em slightly better than the "Marco Fatso" if I had to pick just one .
    I guess there's more than one kind of "head room" . :D

    [​IMG]
     
  18. martyhk0

    martyhk0 Member

    Messages:
    161
    Joined:
    Mar 30, 2007
  19. mike shaw

    mike shaw Member

    Messages:
    2,195
    Joined:
    Oct 19, 2007
    What should the plate disappation range be for a 6V6 VibroChamp?
     
  20. John Phillips

    John Phillips Member

    Messages:
    13,080
    Joined:
    Mar 17, 2002
    Location:
    Scotland
    About 14W.

    Most idle hotter quite a bit hotter than this, which isn't a good thing really - it shortens the tube life for no very good reason, and actually reduces clean headroom by making the tube clip too soon at the forward end.

    To fix it you need to increase the 470-ohm cathode resistor to either 680 or 820 ohms, or even 1K, and change the cap for a 50V-rated one... I prefer to go up to 50uF as well to retain the bass response.

    Fitting a screen resistor is also a good idea, which helps keep the tube happy too.
     

Share This Page