Theremin isn't working

Posted: 1/9/2010 9:19:17 AM
thegodfather

From: Barrington, Rhode Island

Joined: 11/26/2009

For some reason my Etherwave theremin won't work. It stopped working when I simply turned it off after practice...I turned it back on later and no sound. I was using an amplifier at my school, maybe that messed it up? Now I have it at home and I'm using my own amplifier and it still doesn't work. Any help would be greatly appreciated.
Posted: 1/10/2010 8:30:04 AM
Thierry

From: Colmar, France

Joined: 12/31/2007

a) sure that the power supply is giving "juice"?

b) sure that the audio cable is ok?

c) simple test: Take an old AM radio near the Etherwave, set it to the long wave range and try to find a point where you may hear some interference around 285kHz (pitch oscillators) and around 460kHz in the mid wave range (volume oscillator).

d) if all fails you may send your theremin in for diagnostic and repair (Moog music in Asheville during the warranty period, my repair shop in all other cases).
Posted: 1/13/2010 11:31:29 PM
omhoge

From: New York, NY

Joined: 2/13/2005

I know it sounds silly but is there anything touching the loop? I've had a dangling ear-bud wire touch and mute the theremin then baffle me for aeons till I noticed it.
Posted: 1/14/2010 12:26:26 AM
Thomas Grillo

From: Jackson Mississippi

Joined: 8/13/2006

If you go to switch on, and just hear a pop, but no tone, particularly the charactoristic giggle EWs make at start up, chances are a diode, or more likely one of the two transistors located in the center near the two large blue capacitors has burnt out.

I've had to replace those guys twice on one of my EWs.

Moog music is very familiar with the problem and they can tell you exactly which transistor it's likely to be.

I'd have to open up mine to see exactly which transistor it was that was replaced. Let me know if you need the info.
Posted: 1/15/2010 7:22:10 AM
Thierry

From: Colmar, France

Joined: 12/31/2007

Thomas, this weren't most probably not transistors, but the +12V and -12V voltage regulators (with identical housings as transistors).
Posted: 1/15/2010 10:09:50 PM
Thomas Grillo

From: Jackson Mississippi

Joined: 8/13/2006

Thierry, Thanks for the correction. That's exactly what it was on mine. They looked like transistors. I forgot that those were the power regulators. They are afterall, near the power supply circuit.
Posted: 1/18/2010 5:11:03 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

There are rumors that this defective instrument will soon arrive in France...
Posted: 1/18/2010 11:50:04 PM
Thomas Grillo

From: Jackson Mississippi

Joined: 8/13/2006

I would most certainly hope that's all it is. A rumor.
Posted: 1/21/2010 4:34:31 PM
thegodfather

From: Barrington, Rhode Island

Joined: 11/26/2009

I'm afraid it is not a rumor. You will eventually find a theremin on your doorstep, Thierry.
Posted: 1/21/2010 5:06:07 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

It wouldn't be the first theremin on my doorstep, so don't worry, it will soon be back on yours.

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