"Earthing noise"

Discussion in 'Guitar Gear Talk Forum' started by guitardoctor, Dec 23, 2009.

  1. guitardoctor

    guitardoctor Will Rx for food

    Hi guys!

    Just came back from day two of my big guitar hunt through the major stores of Delhi with another question:

    The store I visited today had a lot of background hum audible through the amplifiers. The clerks blamed it on "Earthing noise".

    The hum was loud with some guitars (Eg. the Squier California strat) and absent with some (Such as the Avion AV1)
    The hum was heard with some pickups and not heard with others (But humbuckers were not exactly immune to it)
    The hum was louder with some amplifiers (almost deafening with Marshall 15cd) and lesser with others (Expensive Laneys seemed to "fix" it)

    So I'm asking here what are the possible causes of hum and what was the cause of the hum I heard. Also, how to assess how quiet a guitar's electronics are with problems like this?

    I should mention that the hum problem was much worse in this store than a store I visited yesterday.

    Thanks guys!
  2. flood

    flood New Member

    use a headphone amp or modeller or something that RUNS OFF BATTERIES. no connections to mains.

    humbuckers not immune to hum are cheapo buckers. my ibanez RG humbuckers still pick up noise in the bucking position.

    single coils are bound to pick up interference.

    the marshall MG15 is a POS and should be outlawed on general principle.

    earthing problems are definitely possible on the whole. but your description makes it impossible to assess where it's coming from. i'd suggest using a POD or something similar that runs off batteries. tel the store to get it's earth fixed.

    also, what kind of lighting did the store have? incandescent bulbs will usually not cause a problem, tube lights are humville, especially with single coils.
  3. rickkkyrich

    rickkkyrich Guest

    How to detect the source of noise

    The fastest way to tell if the amplifier is the cause of the noise, is to disconnect the input cables from the amplifier. If the noise is still there, it may be amplifier; if it's gone, it's a source device inducing noise into the amplifier. If after removing the input connectors from the amplifier you find the noise still present, it will then be necessary to determine if the noise is coming from the AC line. This further isolation may be helpful. Try relocating the amplifier using a different AC service, if the same level of noise is present, the amplifier is likely to be the cause. If the noise is lower, the AC service may be the cause.
  4. guitardoctor

    guitardoctor Will Rx for food

    Thanks a lot guys... This is a big help. What's a POS?
  5. rickkkyrich

    rickkkyrich Guest

    piece of sh*t
  6. guitardoctor

    guitardoctor Will Rx for food

    Ah, of course... Technical terms are difficult for a newbie :think:
  7. rickkkyrich

    rickkkyrich Guest

    even i figured it out now only.. ;)

Share This Page