Help? Problem with DC to AC Transformer

Discussion in 'Amps and Cabs [BG]' started by Spike, Jan 15, 2001.

  1. Can anyone throw any light on this problem?

    Our guitarist uses a U.S. 115 DC Peavey stereo chorus combo which came supplied with a UK mains transformer for UK 220-240 AC.
    One venue that we play has safety trip cut off’s on stage and will not stay powered up when his amp is plugged in. All the power on stage dies. Normal mains outlets are fine, and he never gets a problem anywhere else we play, more that two years with this set-up.

    The venue insists there is nothing wrong with their electric’s, and had this feature put in to safeguard their Bands.

    Our guitarist has checked the transformer and says there is only a coil in it, so not much to go wrong, also confused as it works everywhere else.



    [Edited by Spike on 01-15-2001 at 11:10 AM]
  2. MikeyD


    Sep 9, 2000
    This is a real guess, but I wonder if that one stage is fed by a big GFI (ground fault interrupter) circuit. When somebody says "safeguard", this is what comes to mind. If the amp has even slight leakage between the hot wire and ground, it will trip the GFI, and everything on that circuit will go out. If this is the case, I would look into fixing the amp (and/or putting the proper transformer in it). I could envision some odd transformer being used that might cause this type of problem.

    Another thing to try is try plugging it into a GFI outlet in someone's kitchen or bathroom (the outlet with the reset button in it) and see if it trips.

    BTW, DC has nothing to do with this. Transformers convert AC of a particular voltage to AC of the same or different voltage.

    - Mike
  3. Just to add, the Ground Fault Circuit Interrupter works by comparing the current coming in on the "Hot", or "Live", wire to the current going out on the "Common", or "Neutral", wire. If any current comes in on the Hot and goes out by some way other than the Neutral, then a GFCI will trip. So check to make sure the plug is wired to the amp correctly. Neutral and Ground could be swapped, and the amp would still work in grounded non-GFCI outlets, but would immediately trip a GFCI outlet.

    For Britain:

    Hot wire is Brown
    Neutral wire is blue
    Ground wire is green/yellow

    If you don't know what I'm talking about, find someone who does so you don't get killed messing with this stuff.

  4. Thanks Guys.
    Really appreciated, I'll pass this info onto him.He never gets this problem anywhere else.

    We had a real problem Saturday night. Got over it by using a very long extention lead into the venues kitchen.
    But buy the time we sussed what the problem was, we started 30 minutes late and they were not amused.

    We have 13 gigs there this year and they told us we will loose some of them if it happens again.
    Can't blame them as bands are queuing up to play there.

    Thanks again,