Theremin isn't compatible with my new PA

[wisecistus]

I recently purchased a Kustom PA50 to use with my Moog Etherwave Theremin, which is around 10 years old.

The theremin line out works with my old guitar amp (not great sound, but it works).

The guitar is compatible with the PA50.

My keyboard is compatible with both the guitar amplifier and the PA50.

The theremin is compatible with my stereo.

When inserted into the PA50, the theremin line out does not work (no sound is produced).

My local Guitar Center, where I bought the PA50, toyed with the setup for a while but was unable to remedy the issue(s).

Any ideas?

Thank you.

[Spider76]

the theremin needs a grounded connection. Maybe the other systems were grounded and the PA50 is not? You can try connecting it to a mixer with a grounded power supply and from there to the PA50