Pitch Antenna acting strange

Posted: 7/9/2008 8:26:20 AM

Joined: 7/9/2008

Hey guys,
So I've been reading about theremins and watching videos on youtube for a while now, and I was so intrigued by them that last week I decided to buy the Moog Etherwave DIY kit. I ordered it online from a site called InstrumentPro.com and after a week of waiting it finally came yesterday. I was expecting to have to put it together, as the the term DIY suggests, but when I opened the package, the theremin was completely assembled. The only thing I needed to do was attach the Pitch and Volume antennae.
The theremin itself is still unsanded and unstained, it's just assembled. I thought I was extremely lucky for saving a bunch of money on a DIY kit and have it assembled for me.
So I attached the antennae, and started to figure out how to play it. Now here's where it gets kind of weird. I watched the DVD and it suggests that moving your hand closer to the Pitch antenna makes the pitch higher, while moving your hand away makes it lower. Well, my theremin does the opposite. When I move my hand closer, the pitch gets lower, and further away becomes higher. The pitch antenna is always picking up something as well; as in, when I am not standing anywhere near the theremin, it sounds it's highest note, and only changes when I move near it..It's "Zero Beat" is about 3-5 inches away from the Pitch antenna rather than a few feet away. It's as if the pitch antenna has a zero beat first, then the lowest to highest notes, or in other words, it's completely reversed. Also, the volume knob on the face plate doesn't seem to affect the volume of the theremin too greatly...there's a difference in volume when I turn the knob left or right, but it's barely noticeable. Also worth mentioning is that I attempted playing it in my basement, where the walls and ceiling are about 4-5 feet away from the theremin at any given time (as well as furniture and all that)

So I guess my questions are:
1) Should I be concerned that my DIY kit came assembled, (do you guys think they would have sold me a unit that somebody else assembled and then returned?)
2) How to I fix the pitch antenna so that it is not functioning in reverse

Sorry for the long post guys...It's my first one and I wanted to be as descriptive as possible haha. Thanks a lot
Posted: 7/9/2008 12:33:07 PM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

1. No. They're all like that.

2. I suspect your etherwave works just fine. You have just misunderstood the function of the knobs.

Welcome to the whacky world of theremins, where a knob with volume written on it is not a volume knob.

The pitch and volume knobs control how the theremin behaves when you put your hands in the pitch and volume fields.

Don't worry about the volume knob yet. Set it to 12 o'clock.

Now, stand a couple of inches further from the theremin than you would stand to play it. Turn the pitch knob fully to the left. You should hear a high tone. Turn the knob slowly clockwise and you will hear the tone descend until it becomes silent and then start to rise again. When it went silent, that was the sound of the zero beat zone passing through your body.

Now turn it fully to the left again, then sweep the knob clockwise as before, and stop just as it becomes silent. Now drop your arms to the side. You may hear a low tone. Shuffle forwards a couple of inches and it should become silent again. Now shuffle forward a bit more to the very edge of the zero beat.

Hurrah! You have successfully tuned the theremin to zero beat. The manual recommends that you tune it to the lowest note you want to play, rather than zero beat, and when you become a little more proficient you will probably want to tune to an interval rather than a pitch, but that's for later. For now get the hang of tuning to zero beat.

The volume knob has the same effect on the volume loop as the pitch knob does on the pitch field, but this time instead of moving the zero beat zone it determines how far away from the loop the maximum volume is.
Posted: 7/9/2008 1:20:56 PM

Joined: 7/9/2008

Ah, great. Well, I am a pretty big newb so that's probably why it wasn't working right for me. And I was just confused because when I read the manual it said it was to come with a small bag of parts and I was meant to solder wires together, then when I opened it it was all assembled. Pleasant surprise though haha. But thank you!
Posted: 7/9/2008 3:41:15 PM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

[i]I am a pretty big newb so that's probably why it wasn't working right for me.[/i]

Yup, etherwaves have a built in newb detector that causes them to behave strangely.

(The newbs behave strangely, not the theremin.)

Anyhow, I'm glad that sorted it for you. What sort of music are you thinking to play?
Posted: 7/9/2008 4:07:07 PM

Joined: 7/9/2008

Whatever I think sounds nice really...I have a bunch of effects pedals, so I'm going to throw it through those today. I'm very much into Radiohead (I know they use an Ondes Martenot, not a Theremin), so I would like to add an ambience to some guitar tracks I have. Once I get better at it I would like to multilayer it to make it sound like an orchestra :)
Posted: 7/9/2008 4:46:29 PM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

Cool. So you'll be investing in a looper, then.

Do let us know how it goes with the pedals - I'm slowly building up a collection of effects that are well suited to the theremin - imho - so far I have delays, pitch shifters, ring mod and wah. It's always good to hear about a pedal that hits the mark.
Posted: 7/9/2008 7:51:14 PM

From: Toledo, Ohio United States of America

Joined: 2/22/2006

Welcome to Theremin World!
You should thank Gordon again, bcarr6615; he is a force here at ThereminWorld.
Good luck, and let us in on your progress and the sounds you create with your new Theremin.
We love to listen here!

Posted: 7/10/2008 8:36:42 AM

Joined: 7/9/2008

Gordon, I tried doing everything you said, but the Zero Beat is never any further than about a foot and some away from the antenna. I can really only play it in reverse right now, with the further my hand is away (after the Zero Beat) being the higher pitch. I'm thinking whoever assembled it for me soldered the wires while the pitch knob was turned up, so it's tuning relative to where it was turned up. Any other suggestions? Thanks
Posted: 7/10/2008 9:52:24 AM

From: Kansas City, Mo.

Joined: 8/23/2005

You will need to adjust the pitch coils that are on the circuit board. Your theremin kit should have included a trimmer adjustment tool that you can use for this.
Posted: 7/10/2008 9:58:42 AM

From: Colmar, France

Joined: 12/31/2007


By assembling your Etherwave you might have seen that there are a lot of components on the circuit board which allow an adjustment.

Normally this circuit board comes pre-adjusted, but they cannot know about the specific environmental conditions of your instrument. So you will probably have to adjust ist as described under http://www.moogmusic.com/manuals/HotRodEtherwav.pdf.

No need to buy a frequency counter for that, you may download and install a freeware software oscilloscope tool and connect your theremin to the line-in of your PC.

Take care: When the Etherwave case is open, you have to set the pitch oscillator (L6) at additional 500Hz than described. When closing the cover, it will be just fine.

After staining and painting the case you will probably have to re-adjust the whole thing in case the paint would have metallic components.

Theremins are mimosas...

Best regards from France

...and don't hesitate to come back here for further questions until the theremin will work as expected.

You must be logged in to post a reply. Please log in or register for a new account.