1. You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

8950 tubes.

Discussion in 'Amplifiers' started by datsun66, Feb 22, 2008.

  1. datsun66

    datsun66 Active Member

    Apr 10, 2005
    Likes Received:
    I am looking into replacing the tubes in a amp that is running the 8950. 1x3.
    What tube would be a drop in or something else. Maybe replacing the 4 with 2?
    Just something to kick around. Bob.


  2. AudioShockwav

    AudioShockwav Extraterrestrial Admin
    Staff Member

    Apr 6, 2005
    Likes Received:
    About the only drop in I know of is a M-2057, and it is just as hard to find as the 8950 is.
    The 8950 is a 12 volt version of a 6LF6, the heater runs on 12 volts on the 8950/m-2057 and the heater on the 6lf6 is 6 volt.
    I know the Swan 1200X Amps used the 8950`s ( 4 of them) and many were converted to run 6lf6`s, 6kd6`s and so on.
    So If you can dig up a 6 volt filament transformer, change a few things and re-wire the socket for 6 volt you can get away with a 6lf6,6kd6 or a 6lb6. Another way to go for the 3 tubes is if you can find 3, 40lf6 tubes, you could run the filaments in series, and heat them from a 120 volt line (40+40+40 =120), but you are still stuck with a 8950 driving them.

    Sweep tubes are getting harder and harder to find, and the price just goes up...I remember when you could buy 8950`s from Thrifty Drug stores for around $18 each, they had a box of them in the big tube tester by the front door...If I knew then...... I would have bought a truck load of them.
    I now see 8950`s go for $70 to $80 NOS :glare:
    At times you can find them on E-Bay used in the 25 to 35 dollar range, but that is a toss of the dice.
    There are 5 on E-Bay right now, starting bid is $100

    Or here is a Guy that says he has lots of new ones, $75 Bucks


    I got rid of my last sweep tube amp long ago, and got a Al-811H, tubes are cheap, and easy to find.

    Good Luck.

  3. datsun66

    datsun66 Active Member

    Apr 10, 2005
    Likes Received:
    I wonder if the amp will support a ceramic type of tube.? Take out 4 and install 1.
    Just a thought.

Share This Page

Members Online Now

  1. btu44,
  2. 918Oklahoma,
  3. Diesel Junkie,
  4. autotuner,
  5. 15minigrass,
  6. Jimbo165,
  7. 041
Total: 237 (members: 9, guests: 142, robots: 86)