Mr John P

[John P]

Hi can anyone please comment, I have a Peavey JD Omniac. with Seymour Duncan Pickups and the sound is incredible, I did a gig recently in a theater with a lot of lighting controls on the wall and a hearing aid loop running also.
I started to get feedback without hitting any strings, and had to turn the guitar down to half volume to stop it.
Has anyone had the same issue? did you solve it? did the cure involve further screening of the cavity?
Thanks in advance.

[Jack_TriPpEr]

The two pickups in that guitar are non-hum-canceling singlecoils

https://www.musicradar.com/reviews/g...c-jd-usa-26672

Neck: Alnico Pro II APS-2

Bridge: Jerry Donahue signature tele bridge pickup
https://www.seymourduncan.com/single...ahue-lead-tele

In general, non-hum-canceling single-coil pickups are more susceptible to noise from environments like the theater with its lighting controls that you described. In general, adding shielding can help, but may not be 100% effective in very bad EMI-RFI environments.

https://www.stewmac.com/video-and-id...hielding-.html

Switching over to hum-canceling singlecoil type pickups is a solution that helps even more. Seymour Duncan has a number of offerings like this.

In the meantime, you should be able to mitigate the noise to some extent by using the middle position (Position 3) of the guitar which combines the two pickups which provides some hum-canceling.

[idsnowdog]

Hi can anyone please comment, I have a Peavey JD Omniac. with Seymour Duncan Pickups and the sound is incredible, I did a gig recently in a theater with a lot of lighting controls on the wall and a hearing aid loop running also.
I started to get feedback without hitting any strings, and had to turn the guitar down to half volume to stop it.
Has anyone had the same issue? did you solve it? did the cure involve further screening of the cavity?
Thanks in advance.

Are you talking about microphonic feedback or radio frequency interference? You can reduce RFI considerably by shielding the pickup and control cavities with foil or conductive graphite paint. You can also reduce RFI by twisting the leads for the pickups and eliminating ground loops.

https://flameguitars.co.uk/shielding-a-telecaster/

[John P]

Thank you for the information, have been playing bars mainly without the theater lighting panels etc, the links have been very useful regards John

[Jack_TriPpEr]

This article not not only mentions alternative solutions besides adding shielding, but other potential sources for noise and solutions for those as well.
https://www.premierguitar.com/articl...ence_is_Golden

[John P]

Jack, again very useful information much appreciated thank you !