Acoustic Guitar Pickup extreme feedback

[zoldy]

Hi all I hope this is the appropriate forum to get help with my problem. I have a martin acoustic that has the Aura preamp in it. recently its developed extreme feedback. When playing or at least touching the strings there is nothing. however if I lift my hand from the strings a humm starts that gets louder and louder until its unbearable. I simply touch the strings and its gone. it happens with any amp I have tried. And those same amps I have used for years with this guitar and no issues.

Any idea where I start to troubleshoot this problem?

Thanks in advance

[Alan Carruth]

Is there a grounding issue in the P/U or pre-amp? What's the pitch of the hum?

[zoldy]

Best I can describe is it starts out as a hum but becomes a screeching

[zoldy]

is there a simple way to test grounding on an acoustic with pickup and preamp?

[Alan Carruth]

I'm not familiar with this particular setup; it may or may not be easy to check the shielding all the way back to see that there are no gaps. This is not the sort of thing that can usually be done via ASCII text: you need to get the guitar on the bench of somebody who knows about the system.

[mirwa]

Originally Posted by zoldy

Hi all I hope this is the appropriate forum to get help with my problem. I have a martin acoustic that has the Aura preamp in it. recently its developed extreme feedback.

The Aura system has provision to do a factory reset, have a read up and do the reset first, if its still playing up after this, then contact martin to see where a replacement system can be sourced.

Steve

[jonfields45]

The Aura is based on a Matrix under saddle transducer. If the UST's shielding is compromised, it is possible that is your problem. It is generally a pretty simple replacement, though not particularly cheap...

The Matrix UST is well known for eventually developing a ripped shield and humming.