Picking up the monitor feed??

[akivisuals]

Hey guys. I was playing my Cobra this Sunday at my church and was getting the monitor feed coming through my amp when I split my humbuckers. I play in that pickup config all the time and this is the first time where something like that ever happened to me. It was fairly loud. When I switched over to full humbucking it went away. Any ideas what the issue is? Do I need to take the Cobra in to the shop?

[pipedwho]

Hearing aid induction loop?

[tom]

can't think of anything in the guitar that could change that could do that.
i suspect some "new" interference. single coils are going to be more prone to pickup extraneousness signals.

[GuitArtMan]

Arfe you guys using wireless monitors or mics or something? A single coil is going to be more susceptible to noise than a humbucker - just the nature of the beast.

[akivisuals]

Some of the musicians are using in-ears but half of us are using standard floor wedges. We do also use some lavs but it has never been an issue before.
The strange thing is that we haven't really changed our setup at all in the past year. But just last Sunday I started having this real strange interference issue. Never anything remotely similar in the many weeks previous to this. I'll have to check with the sound guys to see if they added anything new to the mix last week.


Pipedwho- I have no idea what a "hearing aid induction loop" might be.... Can you shed some light on this for me?

[pipedwho]

Pipedwho- I have no idea what a "hearing aid induction loop" might be.... Can you shed some light on this for me?
Many churches and other large venues have what is called a Hearing Aid Induction Loop. It is basically a large loop antenna that is placed under the carpet/floor boards that induces a relatively large magnetic field. There are hearing aids that have a switch on them to active a magnetic loop receiver so they can hear this modulated field. This lets the hearing impaired hear a very clear mix of what is coming through the house speakers (without any problematic reverb). The FOH is usually sent untouched to the induction loop amplifier so the user can hear whatever is coming through FOH.

Unfortunately, these same systems are picked up just as clearly by a typical single coil guitar pickup.

I'm not saying that this is the problem. But, I've had it happen to me enough times at various churches that I no longer depend on split humbuckers or traditional single coils. The most annoying side effect is uncontrollable high pitched feedback at even fairly low gain settings.

[bruce]

I was going to suggest a ground loop issue, but the hearing aid loop sounds interesting and highly possible in this senario.

Magnetic fields = No bueno for guitar players

[tom]

hey bru, what's the most common solution to a ground loop where one amp is in a different room for power. i talked to a customer today with a crowdster plus who's getting electric amp hum when the acoustic is in a DI?

[akivisuals]

I don't think we're using a hearing aid loop so that's probably not the issue... Would a ground loop pick up a monitor feed or would it sound like a hum?

[bruce]

hey bru, what's the most common solution to a ground loop where one amp is in a different room for power. i talked to a customer today with a crowdster plus who's getting electric amp hum when the acoustic is in a DI?

The things I would try..

First, try lifting the DI input at the sound board.. and/or at the DI itself... (try lifting both combinations separate AND lifted together).

If those don't work, then plug the amp into a different power source. If this still doesn't work, repeat the above again while the amp is in the new power source.

I try to keep one amp grounded and lift the other things that are add-ons.