so weird.

Posted: 3/11/2008 12:28:13 PM

Joined: 3/11/2008

i just recently built a theremin from the kit. When the cover is off it plays fine. When the cover goes on theres no volume control. Anyone have any help on this subject
Posted: 3/11/2008 1:11:27 PM

From: Connecticut

Joined: 10/10/2007

What kit is it?

Are you sure the cover isn't touching any of the components?
Posted: 3/11/2008 4:32:02 PM

From: Escondido, CA

Joined: 2/6/2008

Check your connections to anything attached to the top cover, or as was suggested earlier, look for something the cover is hitting when it is installed.

Posted: 3/15/2008 11:35:47 AM

Joined: 9/25/2007

I experienced a similar problem with my home made Theremin. Does the Theremin have zero volume with the top shut? I noticed that the placement of any internal wires effects both volume and pitch tuning- make sure that any wires that can move stay in the same place; I used small pieces of velcro to hold themdown.

Also, when I closed my Thermin's top, the volume tuning would often greatly change, because closing the top puts a quite large (though not conductive) object closer to the volume field. Because of this, I had to tune my volume to being louder than normal with the top open, and closing the top dropped the volume back to normal. I'm not sure what kit you have, but if you take a look at the volume tuning section at
you'll see that by louder, I mean that I tuned it so that the voltage at pin 12 of U3 was above zero.

Hope that helps,
Posted: 3/15/2008 11:17:14 PM

From: Toledo, Ohio United States of America

Joined: 2/22/2006

Is the top of your Theremin cabinet made of wood?
Wood is an organic material that effects the pitch rod as well as the volume loop of most theremins in some situations.
This is not a 'weird' thing--- it is a physics thing.
Try to mis-tune the volume side of your Theremin kit's inductors, so that the closer you bring the lid of you cabinet to where it shall rest after it is secured, the Theremin just starts to make a sound. After the top/lid of the cabinet is affixed, re-adjust the front panel volume null so that your Theremin works to allow volume as you bring your hand away from the volume loop.
I assume that the kit may have came with a construction/tuning manual--- perhaps another reading of that document might help.

Good Luck!


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