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Mods to a 1969 Ampeg B25 head?

Discussion in 'Amps and Cabs [BG]' started by Doomjammer, Apr 25, 2018.

  1. I have a 1969 Ampeg b25 head, i am wondering if there anyone knows of possible mods i can do to get a little more wattage or should i just use it as a preamp? I have a volume box for it that i keep cranked the whole way with the amp turned about half way up, im in a stoner doom band and love the gritty overdriven tone i can get from it but its not loud enough at 55 watts, any possible mods or should i use it as a preamp for my Peavey mark 2 standard head.
  2. The power output of a tube amp is controlled by the power level and the tube type used. You cannot increase the output in any way that would matter. To get the amp twice as loud you would have to increase it’s output by ten times. Adding more speakers will increase the apparent volume.
  3. BogeyBass


    Sep 14, 2010
    Aside from the usual tube amp tune ups
    Like Caps and bias.

    Otherwise to make low watts louder its all about big piles of matching speakers that have correct impedance. So you can run a buttload of them on either the 16 ohm or 8 ohm tap.

    So that would be a cool mod as well having separate 16 tap and 2 parrallel jacks on the 8 ohm tap.

    With say custom 16ohm 4x12 cabinets
    And a pair of those for 8x12
    Would really wake up that 50 watts
    michael brown likes this.
  4. Thanks! I run it through either an Ashdown 8x10 or a Silver face Peavey 2x15. It sounds great through either but just looking for possibilities, would using it as a pre amp for my Peavey head be an option as well?
  5. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    No. Tube amp with no speaker hooked up = blown tube amp.

    Want to get a little more out of it? Sell it and buy a V4B :D
    daveman50 and lowplaces like this.
  6. Would i be able to run that as a slave to the Peavey? Have it hooked up to a cabinet but then run a cable from an input to the Peavey?
  7. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    That you could do.

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