Need help with Open Theremin

Hey all,

I have an Open Theremin and I have been quite happy with it until recently. I used to play it everyday but i stopped playing for a little while because of work and after i set it up again, it was making very strange sounds, like a screeching noise or static buzzing, when i move my hand around the pitch antenna. The sound it made used to be very clear and pleasant but now it's basically unplayable. I'm sending the links to the voice recordings so you can hear what i am talking about (you can listen without having to download it).

I plugged it into the same outlet i have before, and the outlet has a little sign on it that shows if the outlet is grounded or not (it says it's grounded), so i am not sure if it is a grounding issue. I am wondering if replacing the arduino might work. I'd be very grateful if you guys could help me out with this as i love my theremin very much and i really would love to go back to practicing everyday with it. 

here is what it sounds like when i move my hand around the pitch antenna:
before calibration: https://voca.ro/1e1iunEagGa1
after calibration: https://voca.ro/13KJqZulEO2K

Thanks in advance for your help and suggestions, 
have a great day.

I don't think replacing the Arduino board will help. 

Try setting all the knobs mid-range, and then hit calibrate. Then step away a few feet and let it calibrate. Usually that brings things back into manageable range. 

I find that this is necessary even if I move the Open Theremin into another room. 

Hope that helps!