HELP genz benz 750 noise

Discussion in 'Amps and Cabs [BG]' started by 3eyedfish, Jun 30, 2008.

  1. 3eyedfish


    Jul 23, 2007
    Im having a hard time figuring out this static like crackle out of my rig.At first i thought it was the preamp to my active shcecter bass.I got a wierd pop when i made contact with the backplate.After replacing that and painting the shield cavity in the back it seemed ok for a while.Just a few minutes. then it came back.its odd because it doesnt do it first then it gets going and doesnt stop.I notice its when i turn the fader between pickups all the way to the left it stops.Could this be a bad pickup?I think its the amp head and not the cab because the sound comes out when i plugged in directly to a soundboard and both channels.I have a bg 750,Ampeg410hlf classic,and a shcecter studio 5 string.I use both channels often and have my bass turned most the way up as far as the preamp controls and volume.PLEASE HELP.Any ideas on my problem.:help::help:
  2. Does it subside a little if you stand at right-angles to your amp, or move a substantial distance from the amp?
  3. 3eyedfish


    Jul 23, 2007
    No.Its not a feedback type noise. It almost sounds like a blown speaker but it makes th same noise through direct recordings.
  4. Jake deVilliers

    Jake deVilliers Commercial User

    May 24, 2006
    Crescent Beach, BC
    Owner of The Bass Spa, String Repairman at Long & McQuade Vancouver
    You'd get better answers in the Bass Guitar Forum - you're on the Double Bass side here. :)
  5. CrashClint

    CrashClint I Play Bass therefore I Am

    Nov 15, 2005
    Wake Forest, NC
    DR Strings Dealer (local only)
    My GBE600 did something similiar. My amp tech opened the case and hard soldered all the grounds to the chassis and replaced the tube. While he was in there, I had him replace the fan, which had started to make a little noise. When I got the amp back it was quiet.
  6. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Does the noise happen only while playing or ifthe bass is just sitting there?

    Does the amp make noise without anything plugged into it?

    Are you using any outboard effects?

    Have you tried the amp with another bass?

    Is it a noise or a distortion sound while playing?

    Have you checked the preamp battery contacts and checked the bass's output jack nut to be sure it's tight and the ground is solid between the output jack and the bass's internal ground?

    Let me know and I'll try to figure this out. It may have nothing to do with the amp so I'd hate you to go through the hassle of troubleshooting the wrong component.
  7. 3eyedfish


    Jul 23, 2007
    It happens when i play and seems to start when i hit a hard note.The amp doesnt make any noise without bieng pluged in.No effects and i have played with another bass.The noise didnt come back but it as also fine yesterday with my original bass.I dont know if its distortion.It sounds like crackling or hissing.I just had my bass checked top to bottom because I thought it was the bass.It would snap or hiss kinda like the sound im getting now when i made contact with the backplate.Painted the shield cavity and is fine now but i wonder if i caused damage somehow.My bass doesnt make the sound out of my other amps.
  8. smogg


    Mar 27, 2007
    NPR, Florida
    I'm not crazy, I'm just a little unwell
    sounds like a bad ground on the back pup to me
  9. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Well, PM me if the noise returns and I'll help you troubleshoot.