Is this normal for Etherwaves?

Posted: 4/13/2005 5:21:11 PM

From: Portland, OR, USA, Terra, Sol, Milkyway

Joined: 3/1/2005

I noticed that when I was practicing today, that sometimes when I touch my volume loop antenna I get a slight chirping sound. It only happens when I am actually playing a note with my pitch antenna and not when I touch the volume antenna by reaching in from outside of the control field with the theremin at zero beat. It seems to happen more when I lightly touch the volume antenna near to where it attaches to the theremin's case and not so much when I touch the antenna on its farthest point from the theremin's casing. This only happens intermittently and it doesen't happen each time I touch the volume antenna while playing a note.

The theremin is a Moog Etherwave.

Is this normal for Etherwaves or did I get stuck with a slightly defective one?

Posted: 4/13/2005 10:07:29 PM

From: Hillsborough, NC (USA)

Joined: 2/13/2005

It's possible your Etherwave is tuned in such a way that depending on the notes you're playing & the with added effect of touching the volume antenna, the pitch and volume oscillators interfere with each other. You can try tuning the fixed oscillator of the pitch antenna higher and then re-nulling the variable oscilator to see if that helps. I'd also check the connections to the volume antenna, just in case there's a cold solder joint or perhaps a flaky connection.
Posted: 12/22/2005 8:26:19 AM

From: Richmond Hill, Georgia

Joined: 9/18/2005

I've got a brand new one for Christmas, and it does it right out of the box. THe people at Moog said it was normal and not to worry.

Posted: 12/22/2005 9:01:35 AM

From: Kansas City, Mo.

Joined: 8/23/2005

From what I have been able to observe with the Theremax and the Epro, is that touching the theremin causes a change in pitch. In fact, on the Epro, touching the metal controls will alter the pitch. The volume antenna seems to be no exception.

There is no audible chirp on the Epro because its volume circuit mutes the sound entirely well before one touches the volume antenna. I have done the same on my Theremax -- it took a bit of time however I was able to adjust my volume circuit so that just a "split second" before touching the volume antenna the signal is muted.

Back to the Epro -- when monitoring thru the pitch output (which bypasses the volume circuit) guess what? Yep -- you get a change in pitch when touching the volume antenna. The chirp is there, however it is fully muted.

The other revelation is that the pitch-change-from-the-volume-antenna starts slightly before touching the antenna. The workaround to this is, when tuning the pitch circuit, to check the effect of the volume antenna on pitch -- and to find coil settings (frequencies) where the pitch change from touching the antenna is minimal.

This may be different on other Theremin designs however on my instruments the "chirp" is there however is not audible.
Posted: 12/23/2005 9:30:09 AM

From: Hillsborough, NC (USA)

Joined: 2/13/2005

Congratulations hypergolic!

At Ethermusic 2005, I saw the tVox Tour comes with a thin pastic sleeve around the base of the pitch antenna - about 5 inches tall. George Pavlov (Lydia's husband) explained to me that it's there so she can get very close to the pitch antenna and even touch it without causing the chirp. If she wants to produce the chirp (which she used quite effectively in a couple of songs) she just touches the antenna directly above the sleeve.

You might be able to do something similar with your volume antenna. I believe Clara herself had tape or something wrapped around her theremin's volume antenna so she could rest her hand on it without causing a chirp.
Posted: 12/23/2005 6:35:03 PM

From: COWafornia

Joined: 3/23/2005

Yes video of Ms. Rockmore shows tape around the base - I thought it was broken! This is simply briliant!

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