Weird Oscillation Sound from Bass

Discussion in 'Pickups & Electronics [BG]' started by RenR, Nov 23, 2012.

  1. RenR


    Nov 23, 2012
    Sorry if I've posted this in the wrong place.

    I Started learning to play bass about a year ago. I have an Ibanez GSR200. Even though it's a cheap-o bass, I love the thing and have taken great care of it. Yesterday I started getting strange sounds out of it.

    When I first plugged the bass into the amp, it played fine for about 30 seconds. Then the sound started cutting in and out at a steady rhythm of about twice per second. It sounded like a really slow oscillation effect. Since the amp was borrowed, I thought there was some setting on the amp I wasn't aware of, so I plugged into another amp. Same thing happened - sounded fine for a few seconds, then the cutting out steady oscillation started. I changed cables to make sure there wasn't a short in the cable and the sound still persisted. It also seemed that the tone sounded a little "tin can" -ish. I finally went sans amp and plugged directly into my computers sound system, and still the same issue.

    Since I've tried a new battery, different amps, and changing out the cable, I have to assume that it's an issue with my electronics. Any ideas? I tried turning down the separate pick ups, thinking either the P or the J were bad, but no matter what I did it still sounded the same.

    Thanks for the help and the patience. This is the first time I've had an issue like this, so I'm clueless.
  2. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    The only non-broken thing I can think of is that the pickup(s) may be too close to the strings and you're getting a magnetic thing happening. But since the bass was working fine before, I doubt it. I'm no tech, so I'll leave that to greater technical minds than mine, but it does sound like something went bad with the preamp.
  3. JimmyM, sounds like some loose wiring in the bass, possibly at the input jack. You should be good to go in no time!

    - Jimmy Rage
  4. bassbenj


    Aug 11, 2009
    This pretty much sounds like problems in the bass electronics. First cut on that is a new battery. And I mean NEW battery not just a different one. Make sure it's alkaline within expiration date. Even try a couple of them.

    And then when trying them, twiddle the tone controls from one end to other. that may make the effect come and go. In fact twiddle ALL the knobs looking for the effect to come and go.

    If the problem remains it's probably oscillations or parasitic oscillations in the bass preamp. Oscillations would be a low frequency modulation on the signal, parasitic oscillations would be an ultra high frequency oscillation that is so high you can't hear it. But it effects the rest of the tone.

    The only true way to find parasitic oscillations is to probe around with an oscilloscope. And typically the fix for this problem is a whole new preamp. Sometimes it's a cap or something that dies that causes it, but finding which part is bad is more work than simply ripping the whole thing out and replacing it.

    My Alembic had this problem for certain settings of the tone controls. Until the factory sent me a new preamp the fix was simply to not turn them there!

    Good luck!

    PS. I own a GSR206 and it is simply one DYNOMITE bass. You do NOT want to get rid of that! Do what it takes to fix it.