Moog Music Forum

Hi everyone. Very new (<24 hours) owner of Theremini. It's working great, except I notice the built in speaker is constantly emitting a warbling sound, like some kind of RF interference. Not very loud, but certainly noticeable. Very similar to putting an AM radio next to a computer, for example. The level doesn't change regardless of the volume pot position, but the speaker is silenced when headphones are plugged into the front panel socket. The headphones and line outs are completely clean by the way. Do they all do this, or have I got a dud?

Thanks - Robin

I have exactly the same problem. As there was no reply to this question I assume I too have a dud.

I never got to the bottom of this. I returned the Theremini to the retailer, who agreed it was noisy, and changed it for something completely different. I didn’t really get on with it.

bigmeister wrote:I never got to the bottom of this. I returned the Theremini to the retailer, who agreed it was noisy, and changed it for something completely different. I didn’t really get on with it.

Thank you for the reply. I too am at the exchange or refund stage with a product that I otherwise really love. I can play it after just a couple of hours practice.

Anyone on this forum who has a Theremini - be it with or without a noisy speaker - please let me know.

Hello, I'm new here and also new in the theremin world. I've recently bought a theremini and I LOVE it. however, I also recognized on the first day that the speaker makes a weird noise, even when I mute the theremini. Playing it with headphones or a speaker seems to be fine, so the speaker is the problem. I think I have to contact the retailer and ask for an exchange

I know it's an old thread but did this problem ever get fixed?
My new one (2022) has a similar warble. Tried various things suggested by tech support but the only 'cure' I found was to run it from a 12v gel battery - the background noise completely disappears.
If they're all like this, there's no point sending it back for an exchange.

If the noise problem goes away by running it on a battery (pure DC), then it sounds like a power supply problem.