I'm causing a ground problem.

[Mike M.]

This is too weird. I'm going to be playing acoustic guitar in the band at church for a while. The setup is: acoustic guitar with a pickup under the saddle plugged into an acoustic guitar preamp. The preamp is then plugged into a direct box which goes to the PA. We all use in ear monitors and have our own mixing stations.

For some reason I had a very loud hum coming from my setup. They said this came out of the clear blue and they've never had this problem before. We tried this, we tried that and the hum wouldn't go away.

Long story short, whenever anybody else holds my guitar and uses my ear monitors the hum goes away. The soundman tried it, the other guitar and bass player tried it and so did one of the singers. No noise at all but as soon as I held the guitar and used the in ears the loud hum came back.

I've never heard of a person causing a hum/ground noise like this but apparently I am.

What to do? Take the metal plate out of my head?

[T-Bird]

Hi.

That's a really strange one.

Does the ground lift on the DI have any effect at all?

Does changing the guitar affect anything? If there's another piezo equipped acoustic guitar around.

Regards
Sam

[Mike M.]

Originally Posted by T-Bird

Hi.

That's a really strange one.

Does the ground lift on the DI have any effect at all?

Does changing the guitar affect anything? If there's another piezo equipped acoustic guitar around.

Regards
Sam

Changing the ground lift had very little effect. Here's what's really strange. The first time this happened I was borrowing the other guitar players setup. His guitar, his cords and his preamp. This past Tuesday I used my guitar, my cords and my preamp. Same thing happened. A loud hum came thru the PA when I was hooked up but as soon as the other guitar player took my guitar and in ear monitors the hum went away.

What's wrong with me?

[T-Bird]

Hi.

I have seen articles about people who can cause RFI, but all those articles have been in magazines or websites that deal with UFO sightings and abductions as well .

We all have a different conductivity and internal resistance though, and it may be possible that it creates the ground loop. Got sweaty hands?

Most of the times a random RFI causes trouble, it's something trivial: Wrist-watch, tuner, cell-phone, PDA, pacemaker etc. There's been threads about strange interferences on TB in the past, but as searching for them is next to impossible, lets hope that someone who participated on those threads remembers better and could provide a link.

Regards
Sam

[Mike M.]

Originally Posted by T-Bird

Hi.

I have seen articles about people who can cause RFI, but all those articles have been in magazines or websites that deal with UFO sightings and abductions as well .

We all have a different conductivity and internal resistance though, and it may be possible that it creates the ground loop. Got sweaty hands?

Most of the times a random RFI causes trouble, it's something trivial: Wrist-watch, tuner, cell-phone, PDA, pacemaker etc. There's been threads about strange interferences on TB in the past, but as searching for them is next to impossible, lets hope that someone who participated on those threads remembers better and could provide a link.

Regards
Sam

Sweaty hands? No. Wrist watch...don't own one. Cell phone...left it in the case.

UFO abduction? I don't think so, but God's honest truth here (I am NOT making this up) I have every reason to believe I past thru a time warp back in 1980, but that's a whole differant story!

[ahc]

Shield yourself with copper foil ??? But be careful with the solder