I need schematic ampeg B15-R

Discussion in 'Amps [BG]' started by trompeta, Jan 15, 2014.


  1. trompeta

    trompeta

    Joined:
    Jan 15, 2014
    I have 3 burned resistors and i don't know their values
    R72, R68 and the third one i can't see it.
    This one is next to R72, Could anybody help me?

    http://www.flickr.com/photos/114585537@N08/


    Thanks in advance!!!
     
  2. nashvillebill

    nashvillebill

    Joined:
    Oct 13, 2002
    Location:
    Nashville TN
    I thought I had the schematic, but can't find it, sorry.

    The bigger question though: what burnt everything up? Resistors normally don't just burn up. Looking at the picture somewhere a massive amount of current must've been drawn through them. Before replacing them, it's critical to find out the root cause. Power tube failure?

    All that carbon on the circuit board is not good either, can cause future arcing. A thorough cleaning to bare board is necessary.
     
  3. trompeta

    trompeta

    Joined:
    Jan 15, 2014
    yes, a power tube failure and something more
     
  4. trompeta

    trompeta

    Joined:
    Jan 15, 2014
    Already this repaired and clean, but i cannot find schematic in the web
     
  5. Register to disable this ad
  6. beans-on-toast

    beans-on-toast Supporting Member

    Joined:
    Aug 7, 2008
    R66, R67, R68, R69 are power tube screen resistors 470Ω, 5W, 10%. They should be flameproof.

    R71 and R72 are 100Ω, ½W, 1% resistors. The artificial center tap for the heater. These act like fuses and blow if there is an issue with the tube heater circuit.

    I would change them all. Clean up all the char with isopropyl alcohol.

    You should be able to obtain a copy of the schematic by contacting technicalsupport@loudtechinc.com
     
  7. trompeta

    trompeta

    Joined:
    Jan 15, 2014
    Thanks a lot. I will follow your instructions. Thanks again.
     
  8. BassmanPaul

    BassmanPaul Gold Supporting Member

    Joined:
    Aug 25, 2007
    Location:
    Toronto Ontario Canada
    If the Char doesn't like that, buy her a Martini instead! :D
     
  9. beans-on-toast

    beans-on-toast Supporting Member

    Joined:
    Aug 7, 2008
    They aren't usually that picky. Anything that they can get their hands on suits them fine.
     
  10. nashvillebill

    nashvillebill

    Joined:
    Oct 13, 2002
    Location:
    Nashville TN
  11. beans-on-toast

    beans-on-toast Supporting Member

    Joined:
    Aug 7, 2008
    In England, a charwoman usually looked something like this.


    [​IMG]

    Not to be confused with a tealady


    [​IMG]

    Never to be confused with Charo.
     

Share This Page