Having trouble with Etherwave at 220V

Hello all! I live in the US and have an Etherwave standard with 110 power supply. I am currently on a trip in Indonesia and bought the 220V power supply for the occasion. My theremin is sounding terrible and I'm assuming the 220V is the cause. It sounds as if there are two tones being produced - the correct tone and a lower tone - making the overall tone sound very "buzzy." I can provide a recording if it would be helpful. Any insights are greatly appreciated! Thanks in advance...

Are you playing into a grounded amp or  though headphones?  I wondered if grounding could be an issue.  Good luck....

The obvious difference is that the 110V power supply is grounded, while the 220V power supply is not.

Does the lower tone vary with the theremin pitch, or is it a constant buzz?  (50/100/150Hz?)

What do you have connected to the theremin output?

That’s what I was thinking too.I have heard if you use a long cord laying on the ground to amp it may help, but playing though amp that is somehow grounded is best if possible.  I haven’t had to deal with that but have been thinking of mobile theremin (Playing on float in parade and subsequent grounding issues.)  Hopefully your issue won’t be to hard to work out.  Best luck...

I was originally using a battery powered 10 inch speaker. I plugged the speaker in after learning the 220V is not grounded. The sound went to normal for a while but then the distortion came back. It seemed to randomly come and go as I played. I tried all the inputs and adjusting various settings but nothing specific seemed to be triggering when the sound was normal and when it was distorted. It is not a constant hum, but like a separate lower, buzzy tone that is playing and changing with the normal tone, as well as some tremolo-like distortion. 

I also tried plugging my theremin into my audio interface, connected to my laptop with a small computer speaker. There is still distortion, but doesn't seem to be as bad. The tremolo distortion is not there, but the additional tone is... Here is a short sample of this: https://www.dropbox.com/s/bd2agxwvrtvhtds/theremintonesample.mp3?dl=0

aliamo, you're hearing 50Hz mains hum intermodulated with the tone you're playing:

I'm seeing peaks at 50Hz and 100Hz (@ red arrows above) when you're playing (not there during silence) and this is likely caused by the pitch field picking up the local AC field.  The highest peak is the note you're playing @ 325Hz, the one below it is 225Hz = 325Hz - 100Hz, so it is a "wolf" tone from mains mixing.  The next one up is @ 425 = 325Hz + 100Hz, so another "wolf" tone.  The true second harmonic of the note you're playing is the second highest peak @ 650Hz = 325Hz * 2.

Having 220V going to all outlets rather than 110V probably gives a stronger environmental mains field, though it can sneak in other ways too, like via ground loops.

Dewster - thank you so much for analyzing my recording! I really appreciate you taking the time to do that.  I'm beginning to suspect that the building where I'm staying may not have proper electrical grounding. I read in some forums that many places in SE Asia do not use electrical ground. I suppose if this is the case, there is nothing I can do. Unfortunate situation as I was planning to collaborate with a musician here and record some traditional music with theremin. Going to try plugging in at a different building tomorrow. My fingers are crossed!

     Are you situated so you could run a ground wire out window into earth or other ground source?

"Dewster - thank you so much for analyzing my recording! I really appreciate you taking the time to do that."  aliamo

My pleasure!  Good luck!

Update  - I determined bad wiring in the building was causing my issues. I set up in a different building and the theremin sounded fine. Thanks to everyone for your insights! Learned a lot about grounding in the process of figuring this out.