What makes my amp hiss?

Discussion in 'Amps and Cabs [BG]' started by duo8675309, Oct 23, 2005.

  1. duo8675309


    Jun 5, 2005
    My amp hisses VERY badly, and I noticed that it only does it when the lights are on. Why is this? And can I fix it, or will I have to play in the dark forever? :bawl:
  2. Does it still hiss when you unplug your bass?
  3. probably some bad grounding in your place.
  4. duo8675309


    Jun 5, 2005
    :rollno: No...
  5. X Wolf

    X Wolf Guest

    An AC line filter might help.
  6. fdeck

    fdeck Supporting Member Commercial User

    Mar 20, 2004
    Madison WI
    HPF Technology LLC
    Edited after reading the "when the lights are on" part: Are the lights on a dimmer? Could be the dimmer has gone bad.
  7. duo8675309


    Jun 5, 2005
    I don't have any gain controls. I have a Hartke B150 w/ volume, bass, middle, and high controls. Whenever I turn the high down on my bass (a fender p-bass squier) it goes away. :help:
  8. Tryxx

    Tryxx Sputnik Forums: Bass Mod

    Jun 1, 2005
    Hurst, Texas.
    I used to havea fluorescent light in my room, do you have anything like that. Blacklights, etc.? Could cause a small problem.
  9. Then it's probably not a power line noise problem.

    You said it goes down when you turn down the treble, so it's probably your pickups picking up noise off the lights.

    You could add shielding to your axe, or switch to a humbucking P pickup...but if the lights are flourecent you're kinda screwed.
  10. duo8675309


    Jun 5, 2005
    Well, whenever I touch a string it goes down a little bit.
  11. That's because your strings are grounded through the bridge. Whenever you touch the strings your body is grounded, which adds your body to the shielding on the guitar.

    Sounds like a basic noise problem. The easiest solution is to get some shielding tape or paint for a guitar store, pull off the pickguard, and shield the pickup and control cavities.
  12. jake_tim


    Jun 28, 2005
    North Carolina
    if you have a crappy tweeter liek one of my amps, its may be the tweeter.. i hope you get it fixed, good luck

  13. Kael

    Kael Supporting Member

    Dec 26, 2004
    Oklahoma City

    Hartke heads are hissy. Too bad you don't have one of their heads with the graphic eq. You could just cut the highest fader till it went away. Try bringing down the treble knob some. If you have a tweeter knob, then roll that off some.
  14. Hollow Man

    Hollow Man Supporting Member

    Apr 28, 2003
    Springfield, VA
    This is part of the problem.

    The reason it only happens when your lights are on is because your lights emit high-frequency noise that is picked up by your bass... I'd bet the farm it has single-coil pickups on it. This high frequency noise is then amplified when your treble control is high. This unintentional interference gets sent through your tone control circuit and into your amp. It goes away when you touch your strings (or any other metal part of your bass) because when you do so, you're using your body as a ground that is not susceptible to this noise (unlike the ground in your tone control circuit). Screamingdaisy was right when he said that shielding your bass is the most effective way to eliminate these issues.