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Periodic hiss/crackling coming from my SWR rig

Discussion in 'Amps and Cabs [BG]' started by Philthy, Dec 26, 2003.


  1. Philthy

    Philthy Supporting Member

    Jun 12, 2001
    Wallington, NJ
    I just recently noticed a problem tonight with my SWR rig. I have an SWR Bass 750 head with Goliath III and a Son of Bertha cabs. I was playing around when I noticed a high pitched hiss/crackling noise. However, this noise was periodic and would come and go. It would happen for about 2-3 minutes and then stop. A little time would go by and it would start again. This happened regardless of whether I was actually playing or the bass was sitting plugged in without me plucking the strings. I tried other basses and the same thing had happened. So, I know it's not a problem with the bass. I have the horn on both cabs up about 1/4 of the way. However, when I turned the horns off, the noise would go away. This was happening with both cabs. Is there a possibility that there is a problem with the horns on both cabs? Or could it be something with the head? I'm aware that horns do hiss, especially with treble boosted up, but this was a more noticable crackling hiss that would come and go.

    Any ideas? Any help and advice would be greatly appreciated. Thanks!!!
     
  2. did you try your amp anywhere else? it could be electrical noise.
     
  3. pbd

    pbd Commercial User

    Jul 17, 2003
    Metro Detroit
    owner Procables N Sound
    Ditto!
    When I play my bass at church, we all get to hear how many copies of music the copier is making. Nice:rolleyes:
     
  4. billys73

    billys73

    Apr 25, 2003
    Is there a preamp tube in the input section?
    Sounds like a tube that needs to be replaced to me.
     
  5. Philthy

    Philthy Supporting Member

    Jun 12, 2001
    Wallington, NJ
    I haven't tried the amp in a different location yet but that is gonna be my next step. I did replace the preamp tube about 8 months ago. So, I don't think it's that but you never know. How can you test if a preamp tube is going bad?

    Thanks!!!
     
  6. Philthy

    Philthy Supporting Member

    Jun 12, 2001
    Wallington, NJ
    Ok, I did a little experimenting and it seems as though the one outlet I'm using could be the problem. I moved the amp to another outlet and the periodic crackling seemed to stop however there is still a high pitched buzz that is constant every time I turn the horn up even just a little bit. Is there any way to eliminate that?
     
  7. pbd

    pbd Commercial User

    Jul 17, 2003
    Metro Detroit
    owner Procables N Sound
    Does the buzz go away when you touch the strings? Is your electronics cavity shielded? Try a heavier gauge instrument cable or a shorter one to see if the buzz goes away. The buzz could be coming from flourescents, long filament lamps, motors, etc that are near you and your rig. Do as much changing (one thing at a time) to isolate the cause. The shortened heavier cable worked for me and my old Ibanez.
     
  8. Slot

    Slot

    Oct 17, 2003
    Sydney - The Shire
    You're in luck dude ...because i know exactly what your problem is....

    Ive had this exact same problem with 2 swr cabs now, and intern, i will never buy there stuff again.

    The problem is coming from a lose connection where the speaker wire connects to the control plate on the back of the box.

    Get out ya philips head and unscrew the control plate(where your horn volume control is).........You will see that your speaker wire is connected to this plate using those little male to female slide on clips/plugs.

    simply wiggle those clips around a bit, and that should eleviate the problem. It just makes the connection clean again. Sometimes the connection can get a little corroded and whatnot, and thats what causes the crackle.(you may wanna give all the connections in there a quick jiggle to)


    Hope this is the source of your problem.........95% sure that it will be ......good luck
     
  9. Philthy

    Philthy Supporting Member

    Jun 12, 2001
    Wallington, NJ
    Thanks for the suggestions. I will definitly try checking the wire connections. I appreciate it.

    Also, what do you guys think of a power conditioner? Are they worth it and will they help eliminate buzz? Or will a good surge protector suffice?

    Thanks again!!!!