burst of sound

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by ccuwan, Jun 25, 2008.

  1. ccuwan

    ccuwan Member

    Messages:
    55
    Joined:
    Jun 14, 2008
    I have a Fender Super 60 amp. If I turn off the standby then immediately turn off the main power, I get a burst of distorted sound through my speaker. This does not occur if I wait 30 seconds before turning off the main power. Otherwise the amp is performs excellently which begs the reply....then wait 30 seconds.......sometimes I forget. Any suggestions as to what is happening here or how to correct this.

    Ray
     
    Last edited: Jun 25, 2008
  2. donnyjaguar

    donnyjaguar Member

    Messages:
    4,243
    Joined:
    Nov 4, 2005
    Location:
    Canada
    This has been covered in this forum. Basically what's happening is the power supply capacitors are bleeding away their joules of energy more slowly than the bias circuit capacitors. When you shut down hot, the bias drops quickly thus allowing the amplifier to wind up again for a few seconds. Its really bad on the tubes as they are being called upon to amplify when the cathodes are cooling down, thus creating the possibility of stripping of same.
     
  3. ccuwan

    ccuwan Member

    Messages:
    55
    Joined:
    Jun 14, 2008
    Sorry I'm new to the forum......so which capaitors need to be changed to resolve the problem....power supply, bias circuit or both?
     
  4. SatelliteAmps

    SatelliteAmps Member

    Messages:
    6,185
    Joined:
    Oct 19, 2007
    Location:
    Normal Heights, Calif
    It's not a problem. It's a part of all tube circuits. When you turn off your amp, just turn off the mains, not the standby.
     
  5. Dexter.Sinister

    Dexter.Sinister Still breathing Gold Supporting Member

    Messages:
    5,646
    Joined:
    Feb 24, 2008
    Location:
    South Florida
    Completely normal. Don't panic. Read posts in this forum and other amp forums and all will be revealed. Learning is fun!

    DS
     

Share This Page