Strange TU-2 problem

[Dirk]

Has anybody ever noticed an ultra high pitched sound coming from your amp when plugging an acoustic guitar in a TU-2?
This only happens with my Fender acoustic bass guitar, not my electric basses.
It isn't very loud, well at least not to me, but I'm 41 so I have to put my ear in front of the speaker to hear it, but our 25 year old drummer hears it from across the stage and compared it to one of those ultra sound cat chasers that you put in your garden..

Anyway, this sucks cause now I can't bring the TU-2 on double acoustic/electric gigs, of which we seem to have more and more lately.
Somehow the combination between the bass's Fishman electronics and the pedal is acting weird.
It's not feedback either, I have one of those rubber hole plugs in the bass and feedback is generally much louder and lower in pitch.

Has anybody ever experienced that with an acoustic guitar perhaps?

[Pepe]

I haven't had this issue with a tuner, but I use my tuner without the direct output jack anyway (or a clip-on tuner). My Admira classical guitar has a Shadow Nanoflex pickup and it sounds great, but if I plug it into certain (analogue) pedals, the effect doesn't work as it should. The worst result was when I plugged this acoustic guitar into the BOSS AC-2 Acoustic SImulator. It resulted in heavy hiss. The same goes to some fuzz pedals.

I assume that the TU-2's input and direct output are optimised for the use with magnetic pickups. Do you have access to another guitar with a piezo pickup to check if the problem remains?

[Dirk]

Of course, I'll try it tonight with my acoustic guitar.
I didn't think of that.
Thanks Pepe.