Ampeg V4b Problem

Discussion in 'Amps and Cabs [BG]' started by Tom Neves, Aug 7, 2001.

  1. Gentleman,
    I have a 1974 Ampeg V4b that has recently been giving me some problems when I turn the power on.
    It only takes a few seconds, but the switch goes back to the OFF position.
    I then try to put it back to the ON position, but it seems to resist and not make the connection. After some insistence on my part it will stay on.
    I'm worried about gigging with it and not being able to get it working during a set.
    Do you think this is switch related?(toggle type switch)
    If so, Are there exact factory replacements as I would like to keep it as original as possible.
    Thanks in advance.
  2. Thanks PBG,
    No, I'm not blowing fuses, not yet anyway.
    Are these an easy to come by item?
    Would most electrical supply stores have the switch?
  3. You should be able to find a replacement switch at nearly any RadioShack (or equivalent).

    The main thing to watch is the voltage and current handling (eg 240V 4A or 11V 2A) - if the switch can't handle the current, it'll fry it. Get the same rating and you're sweet.

    You may not find a switch with the matching toggle though (i've had to search through boxes of used switches @ surplus stores to find matches) - so if you're really keen on keeping an "even" look across the faceplate, you might want to replace all 3 switches.

    The only problem I can see with your switch currently dodgy is the possibility of nasty arcing inside the switch when the toggle "floats" between on and off.

    PBG/leckie 'sperts: could arcing cause current spikes at all?
  4. Mr. Grieves

    Mr. Grieves

    Jul 16, 2001
    chicago, il
    I had the "nasty arcing" problem that Nil mentioned after I managed to bust off the stem of my amp's power toggle on a closet door.

    Took it right to my tech, who fixed it with no problem. Not expensive. Not something you'd want to do yourself unless you're comfortable working on tube amps, however.