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Reducing Amp Noise

Discussion in 'Miscellaneous [BG]' started by mattzink, Mar 25, 2003.


  1. mattzink

    mattzink

    Jun 21, 2002
    Bloomington, IN
    hello everyone!
    there is a fairly loud and constant buzz in my amp. i mentioned this to my bass teacher. he says the buzz could be from any number of sources, but he doubted that it was the electronics in my bass since my bass sounds okay through his amp. he says it could be anything - one theory is that my house is not grounded properly, or something like that.

    what i'm asking from you all is this: could you produce a list of common causes of amp noise (that is, the buzz that comes through the speaker cone when not playing; when the strings are muted) and how to fix them?

    thanks, lookng forward to your input. matt
     
  2. Chasarms

    Chasarms Casual Observer

    May 24, 2001
    Bettendorf, IA USA
    Here's a few off the top of my head:

    60-cycle hum: This is noise from the cycle of standard household electric current. It can be reproduced in your amp if the house's wiring is bad or if there is any bad ground.

    Try lifting the ground by either using the switch on the back of your amp. (If it has one)

    Another means of lifting ground is to use one of those little converter plugs that you can buy at about any hardware store that is designed to work with very old home electrical outlets that have no ground. It basically converts a 3-prong 110 to a 2-prong. IF THIS WORKS, PLEASE DO NOT CONSIDER IT A PERMENANT FIX!!!!!!!!!! Playing an amp ungrounded is very dangerous. I recommend it simply as a means of diagnosing the problem.

    Bad ground in the guitar: Does the hum change when you touch the strings? IF so, check the guitar ground

    Poor shielding in the guitar: Radio interference can cause a great deal of noise if the guitar is not properly shielded. Sources of it include lighting, computers, televisions and about any other electronic device.

    Failing cable: If the shielding is broken in the instrument cable it can cause a great deal of noise.

    Failing amp: There are a number of componants in an amp that will create noise as they begin to fail. Have a pro take a look at it.

    Basically, anything in the electronic chain can cause noise. But, if it sounds ok at your teacher's studio, it is probably something other than the bass.

    Chas
     
  3. mattzink

    mattzink

    Jun 21, 2002
    Bloomington, IN
    wow! those are awesome hints! i'll start working through them to see what happens. i know little or nothing about electronics/electricity, so i appreciate the safety hints.

    also, if it might help with other replies, my amp is an SWR L.A. Series, 15 inch speakers. great stuff, chas - thanks!
     
  4. tyson

    tyson

    Feb 9, 2000
    Dallas, TX
    OK.
    I got a new amp.
    I got a new cable.
    I shielded my P-type bass with copper tape.

    Results:
    The loud and annoying electronic buzz WAS reduced in the P-type bass. however, with both the factory US Jazz Bass and the thrown together P-type bass I have there is still a faint electronic buzz that gets louder when my hand approaches the pickups. it's then reduced when i touch the components and fuction as ground for the bass. there is a ground wire going from the pot to the copper shielding but it just seems to me that basses, in general, should be grounded to the Earth...is this true? :confused: