suitable replacement caps for an early b15?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by teefus, Mar 17, 2006.


  1. teefus

    teefus Supporting Member

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    i have a friend's early b15 on the bench right now. there are some wiring "mods" i am probably going to undo. it definitely needs at least a partial cap job. i think the sprague atoms are still available, right? what is a suitable replacement for the asterons? any thoughts? thanks
     
  2. Wakarusa

    Wakarusa Member

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    Here's what I had to do for an SB-12. The caps on the main board are on terminal strips that are secured with the original board mounting screws. You usually have to replace the first input cap with a pair of new caps to get the same voltage rating as well as devising your own scheme for mounting them, since the original steel loop won't work (upper left of image).

    [​IMG]
     
  3. teefus

    teefus Supporting Member

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    very helpful, thanks for the pic. craig
     
  4. teefus

    teefus Supporting Member

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    i just compared my downloaded schematic to the ampeg b15 and woof! it looks like someone completely bypassed the input resistors and went straight to the preamp tubes. the model on the bench says it is a b15 but i haven't found a schematic that matches the layout 100%. the one i have has input 1, stereo input and input 2. from what i can tell both inputs go straight to v1a and v1b, bypassing the board for some reason. has anyone heard of this before? i'll post a pic later tonight. craig
     
  5. teefus

    teefus Supporting Member

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    this one's a real mess. does anyone have any other layout photos or drawings? thanks, craig
     

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