Simple question - tube removal?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Aahzz, Nov 30, 2005.


  1. Aahzz

    Aahzz Member

    Messages:
    659
    Joined:
    Sep 30, 2005
    Location:
    Greater Cincinnati (Union, KY)
    I want to try some different preamp tubes in my new amp - doesn't seem like that'd be too difficult. I can remove the aluminum cover, then what? Just pull? There's also an aluminum base, and not much tube is exposed - do I need to remove that too? Thanks for answering a simple question - I searched on "tube removal", but couldn't find anything specific...
     
  2. tonezoneonline

    tonezoneonline Member

    Messages:
    437
    Joined:
    Dec 15, 2003
    Location:
    central Illinois
    Remove the tube shield and then just pull the tube straight out.If it's difficult you may rock it from side to side slightly.
    The other aluminum part has nothing to do with the tube.It's the mounting for the tube shield.
     
  3. Kiwi

    Kiwi Silver Supporting Member

    Messages:
    3,762
    Joined:
    Mar 1, 2002
    Location:
    In a white room
    Getting them out is fairly easy, as noted above. Be careful when putting them back in!

    You will notice that there is a space in the even ring of pins at the base.

    Look at the socket and see where and how its space will match the ring of pins.

    Lower the tube gently into the socket and lightly rotate it on the base till you feel the pins match and the tube settles in a bit. It requires a bit of touch.

    Then it's okay to push hard and straight down to seat the tube.

    Be careful when lining up the tube and the socket - you don't want to bend the pins. If you do, get a pair of needlenose pliers and very gently straighten them again, if they aren't too bent.

    GK
     
  4. Timbre Wolf

    Timbre Wolf GoldMember Supporter Gold Supporting Member

    Messages:
    8,586
    Joined:
    Oct 14, 2005
    Location:
    Berkeley, CA
    Great advice here, from both replies. I always "rock" the tube gently (actually, I use more of a slow, easy, circular motion), both when removing and putting back in. The key word here is gentle - to avoid the sinking feeling in your gut when a pin snaps, or the silver colored barium, inside the tube, suddenly oxidizes to white (d'oh!).

    - T
     
  5. Wakarusa

    Wakarusa Member

    Messages:
    1,477
    Joined:
    May 7, 2004
    Location:
    Newnan, GA
    A handy device to keep around is a tube pin straightener. It's just a steel form (usually encased in a plastic mount) that you insert a bent-pin tube into to re-align the pins. An absolute must for the unrepentant tube swapper.
     
  6. Timbre Wolf

    Timbre Wolf GoldMember Supporter Gold Supporting Member

    Messages:
    8,586
    Joined:
    Oct 14, 2005
    Location:
    Berkeley, CA
    "Unrepentant tube swapper" That's me! I might put that in my signature.

    Hey, I use the little pin protectors that often come with Mullard CV4024/12AT7WA that were bulk-packed for the military. They work great for straightening pins. Not only am I impressed with Mullard's tubes, but the packaging was first-rate as well.

    - T
     
  7. Aahzz

    Aahzz Member

    Messages:
    659
    Joined:
    Sep 30, 2005
    Location:
    Greater Cincinnati (Union, KY)
    Thanks for the replies - I was able to swap the preamp tubes no problem. I figured that was all there was to it, but I want to be sure before I started pulling and rocking.

    Next question:

    What about power tubes? I noticed a circular, spring-looking thingy on the base - do I have to do anything with that, or just pull 'em straight out? 6L6GC's, if that makes a difference....
     
  8. Wakarusa

    Wakarusa Member

    Messages:
    1,477
    Joined:
    May 7, 2004
    Location:
    Newnan, GA
    You need to use one hand to hold the spingy thing up against the chassis (or at least away from the tube base) while you pull the power tube with the other hand.

    The springy thing is designed to hold the tube in.
     
  9. Guinness Lad

    Guinness Lad Silver Supporting Member

    Messages:
    15,628
    Joined:
    Nov 11, 2004
    Location:
    On top a mountain of Chocolate Chips
    I'll add a couple points based on my experience (f***ups). Be careful and do not bend the tube socket, a bent pin on a tube is minor comared to ruining your tube socket. Make sure your replacement tubes have totally straight pins, one pin out of round might cause you to collapse the brass within the tube socket (big headache to pry apart). Don't press the spring retainers (power tubes) apart with too much force, I had to replace one before because it broke. I guess I used too much force, although it didn't seem like it at the time.
     
  10. Aahzz

    Aahzz Member

    Messages:
    659
    Joined:
    Sep 30, 2005
    Location:
    Greater Cincinnati (Union, KY)
    I figured it'd be something like that....thanks!
     

Share This Page