EW Standard Pitch Antenna Issue

Posted: 3/2/2020 11:57:10 PM
Laura h

Joined: 3/2/2020


I'm new to owning a theremin and I have recently been confronted with a conflict. I've owned my theremin for 3 months now and one month I had it set up on a shelf as I was occupied with other things. My theremin was working properly before I had set it up on the shelf. I had no problems tuning it. However, I just set it up for use again only to find I'm having problems with, what I assume is, the pitch antenna. 

The problem is that I can no longer tune it. I can not reach a zero beat zone as if I stand away from my theremin it remains activated. Nothing has changed in my home apart from setting up my computer that has a wireless wifi antenna. I unplugged this and this made no difference. I have removed the pitch antenna from the theremin while on to test to see what happens... Still remains activated. 

When I had left it on a shelf I left both my volume and pitch antenna screwed in (finger tight as the manual said).

It's mounted on a microphone stand and I just bought a new audio/visual extension cord to see if what I was using to plug it into was the problem... This changed nothing.

I've read on other forums about the top needing to be removed and things fiddled with. This is out of my realm and is something I most definitely cannot do myself. The suggestion to do that also seemed to come from topics where people built the kit themselves. My theremin came preassembled.

I am at loss on what to do and at what has happened.

(I did leave my aux cord adapter in the theremin it of fear of misplacing it. My headphones only display on one ear if it is pushed in all the way which never happened before. I have to slightly pull it out now for both sides of the headphones to play... Was leaving that plugged in there a possible culprit?)

Posted: 3/3/2020 1:11:55 AM

From: 60 Miles North of San Diego, CA

Joined: 10/1/2014


A theremin needs a good earth ground from somewhere to work properly. If your EWS wal-wart has three prongs that is where it will get it. If not you must use a power amplifier that has a three prong plug into the wall. What you describe are the symptoms and a good place to explore.

The headphones are stereo plugged into a mono jack, that behavior is normal. You need a headphone amp here, grounded would be ideal. This may be where you lost your earth ground, changing from the grounded power amp.

my sound wav
from lost knowledge

Posted: 3/3/2020 1:25:41 AM
Laura h

Joined: 3/2/2020

Welcome,A theremin needs a good earth ground from somewhere. If your EWS wal-wart has three prongs that is where it will get it. If not it must use a power amplifier that has a three prong plug into the wall. What you describe are the symptoms and a good place to start.Christopher  my sound wavfrom lost knowledge

Hi Christopher,
What I don't understand is that I am playing it in the exact same location and using the same outlet as before. I have even tried a different outlet in my apartment and its the same problem. I am using a three pronged outlet with an addition of a three pronged audio/visual extension cord (which I just bought today to see if it made a difference). As one speaks of grounding, the powder adapter that  was supplied with my new EW Standard only has two prongs. 
Thanks for your reply!

Posted: 3/3/2020 11:20:27 AM

From: züriCH

Joined: 3/15/2014

hello laura,
they can change with humidity, temperature, northern-lights and god-knows-what.

retuning it would be a little thing to do, but you think it’s above your skills, opening the bloody box and retune that sucker. 
(did you get a red pencil-like tool with your theremin?) if so, then we could guide you through the tuning procedure, so that the pitch tuning pot is back in it’s range. it’s really not that difficult.
of course, if it’s defective and you bought it new you can return it as long you have guarantee on it.

but maybe first figure out what else causes you trouble. 
some more questions,  4expl.: you don’t mention what kind of amp/speaker do you use? is that one grounded? (with a three-prong plug?) or.: ok,  it doesn’t reach zero beat, but does the pitch still change with hand movement?
where are you located on that planet?

Posted: 3/4/2020 6:52:33 PM

From: earth

Joined: 5/8/2017

If it worked before I suspect you may simply be plugging it in differently. You need a long instrument cable and it should be laid on the floor - that is your ground. You may also want to have some contact between your body and the instrument cable. That is the simple solution.

Novel solutions before opening it up and retuning the coils - most likely the solution, but . . . 

Attach some aluminum foil to the antenna - to make it "bigger" or make a shorter pitch antenna and swap it out when needed.

For some time I used a copper coil as an antenna with some soft foam in the void to dampen oscillations - the antenna could easily be compressed or lengthened to compensate for unwelcome conditions. 

And when you do resort to returning the coil(s) - keep in mind that everything will change when you put the case back on so guesstimate - and expect to do this a couple of times to get it right.

Unless it is a component failure somewhere else.

If you want to make different length pitch antennas - toilet intake pipes at any hardware store - get the compression fitting as well.

But for Captain Obvious's take - if you plug your headphones into the output of a theremin and expect to play it - YOU GET NOTHING!

Plug it into an amp or mixer and plug your headphones into the amp or the mixer.

Good Luck! 

model 302 never fails.

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