Horrible Chirruping Sound - Earth Loop???

Discussion in 'Microphones (live or studio)' started by Jeemy, Jul 26, 2004.

  1. Jeemy

    Jeemy Well-Known Member

    Sep 19, 2003

    My setup is as follows:

    1 live room with 16 feeds through inc. returns to a "control room" with Mackie 1642VLZ desk into amp & monitors.

    If I connect everybody through mics & XLRs to the desk that is fine.

    However if I connect a bassist through a SansAmp DI box to the desk, a chirruping noise appears on the desk. Pressing the ground Connect switch to disconnect ground removes it in the control room, but makes it appear in the live room amp instead?!

    Manageable or so I thought. Until I tried to record 2 acoustic guitars using Fishman pre-amps, direct into the desk, and the chirruping sound appeared again. Regardless of using DI boxes it would not disappear.

    Does anybody have any hints as to how I can fix this? Tearing my hair out.

  2. Patty D

    Patty D Guest

    try plugging all amps into the same grounding source (electrical). Monitor amps as well as instrument amps. Be sure to check the circuits being used and see if there may be a motor or other noise generating device plugged in. Check, of course, all instrument cables for malfunctions. Let us know what you find.

Share This Page