Earth Loop / Chirruping Noise / Help!

Jamie · Post by **Jamie** » Tue Jul 27, 2004 1:14 am

Hi,

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 within the control room, and the chirruping sound appeared again. Regardless of using DI boxes with ground float / lift it would not disappear.

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

Jamie

giles117 · Post by **giles117** » Tue Jul 27, 2004 2:30 am

And all your equipment is sharing a common ground and a common Neutral?

Post by **Aaronw** » Tue Jul 27, 2004 3:02 am

Does your DI have a fresh battery? Is it powered by Phantom power? Are you giving it both battery & DI power?

Check your grounds. Also, try different cables. Maybe one's shorted out.

Betsy · Post by **Betsy** » Wed Aug 11, 2004 9:44 am

Maybe not the prolem buy my electrician dropped the energy company ground and installed one in the ground connected to a 10' rod underground.

giles117 · Post by **giles117** » Wed Aug 11, 2004 10:06 pm

Let us know if it has improved.

Guest · Post by **Guest** » Thu Aug 26, 2004 8:54 am

Hi Guys,

No my electricity is probably on more than one earth. I have the building for 2 years after which I will purpose build.

So my cures have ended up being preventative rather than curative.

The use of a humbucking pickup in the guitar improves things.

Aside from that I can't cure acoustic guitars on pickups. But there we go, you can record that anywhere.

Any problems created when linking live room amps to the control room mixer are solved by lifting the earth on the amp concerned and letting it find its ground through the shield wire on the cables so it shares earth with the mixer.

All metal casings have been voltage-tested and I made a couple special kettle leads with skulls'n'crossbones on 'em and put in power breakers.

Well, it works....

Jamie

royaltoon55 · Post by **royaltoon55** » Sat Jan 31, 2015 5:44 pm

is it ever coming together! I just saw a few new links that I gotten over the years with great difficulty and then proceeded to foget about the work getting them.

Great resource just getting better and better!

Soundman2020 · Post by **Soundman2020** » Tue Feb 03, 2015 2:53 am

royaltoon55 wrote:is it ever coming together! I just saw a few new links that I gotten over the years with great difficulty and then proceeded to foget about the work getting them.

Great resource just getting better and better!

And you are commenting on a thread that is nearly ELEVEN YEARS OLD, because.... ?

- Stuart -

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Earth Loop / Chirruping Noise / Help!

Earth Loop / Chirruping Noise / Help!

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