Moog Music Forum

Hi Everyone
I am having trouble with a strange background noise coming from my Theremini.
There is strange oscillating sound in the background all the time.
But this sound is only present when I use the internal speaker or connect it to an external amplifier/speaker. I cannot hear it through the headphones. Also, I can hear it through the internal speaker when the volume is at zero.

Here is a link to a youtube video I made of the sound when heard through an external amplifier:
https://youtube.com/shorts/7xNA9bctNX0?feature=share

I calibrate before each use and have tried the theremin in different rooms of my house so I don't think it is an interference or ground issue (if it was, why do I not hear it through my headphones?).

Many thanks for your help
Best regards
Paul

Hi Paul,

You are not alone, I have exactly the same issue including the clean line and headphone outputs. I have tried different rooms, different ring circuits, using the ground post etc. all to no avail.

Just realised, Paul, you and I have already discussed this issue elsewhere but it doesn't harm to log it here!

Regards,
Steve

Hi guys

I had this exact problem - just the same as the YouTube clip. I changed the power supply. Somehow I had got it swapped with my Yamaha keyboard supply.

With the original power supply the Theremini works fine.

Ade

Thanks for the advice Ade!
I'll try a different power supply.
Cheer
Paul