ampeg b2 sputtering

Discussion in 'Amps and Cabs [BG]' started by downstairs, Sep 21, 2003.

  1. downstairs


    May 13, 2001
    Pasadena, MD
    I have no idea what is up with my ampeg b2, but I'll be playing pretty loud (amp still on about 3-4), and then it will cut out, but the amp is still getting signal. For a while, when I messed with the power cable it would start working again, but then that stopped working, so one day I got aggrivated, and smacked the top of it, and it worked for a little bit....Its just starting to tick me off some. My bass teacher said it soudned like it might be an electronical problem, and I'm thinkin i should open it up and see if there is anything loose up in that, any ideas with you guys?
  2. I have a B2 and had a similar problem...i would play pretty hard for a while then it would start cutting in and out. First, DON't HIT IT ANYMORE!!! Simple check, watch the cooling fan on the thing and see if it works and if it speeds up. Those are supposed to be variable speed depending on temp and when the amp gets to hot it shuts down until it clears a certain temperature. My little fan was not working right so i took it to my local repair dude. $35 later he rigged it up so the fan runs at 1/2 throttle all the time until she gets hot then it goes full throttle. Never had a problem with it since. To verify, pop the top on the head (or pull it out of the combo cabinet) and run it with a small fan blowing on it and see if it acts up. When i did this mine no longer acted up so i knew it was a fan issue. Apparently this is not a very uncommon problem.
  3. I had a similar problem with my B2 and it turned out to be the on/off switch. It is a quick, inexpensive repair. While the tech is in there, have him install a Switchcraft input jack and save yourself a trip back to the shop. Since I've had these inexpensive repairs done, it has been 2 1/2 years of trouble-free playing.
  4. Have you ever run this amp with anything lower than a 4 Ohm load?
    You can easily blow some of the Hexfets in this amp design by running it at a lower impedence than it is rated for.
    This will cause intermitant signal loss/lowering on higher volumes and lower notes.

    If it is cutting out completely (as in no sound at all) then it could be a temp problem and the thermal protection is kicking in.

    Also these amps can suffer from poor solder joints on some of the connectors, especially where the input jack is soldered onto the pre-amp circuit board.