ther-force one...NEW DUAL THEREMIN

Posted: 12/5/2008 1:53:52 PM

From: Escondido, CA

Joined: 2/6/2008

You might need to strip the insulation off the end you are holding if you want to just wind some wire around an old drumstick. That would create better coupling between you and the theremin's antenna, even though you are not directly touching the theremin antenna.

Ideally you are going to want the theremins to be less sensitive, so that they respond only when you come close to their pitch antennas.

Since this would create yet another tuned circuit in the mix, you might experiment with different numbers of turns of wire on the drumstick ... different number-of-turns should produce slightly different pitch, if things are setup right.

Not sure what "minimum theremin" design you are using. If you build ones that make use of CMOS gates, they may not work well at all for your idea.

Posted: 12/5/2008 1:57:37 PM

Joined: 10/31/2008

i am using the art harrison minimum theremins.

i am not going to be holding the antenna. i want to mount the theremin case on the drumset so that i can swing my hand by the antenna while playing for cool pitch sweeps. i wouldn't be playing with hybrid drumstick antennas...

i think i may have confused some people... sorry!
Posted: 12/5/2008 2:08:10 PM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

No, we're right with you.

The point is, the antenna and your hand (or your wired drumstick) are both part of the theremin circuit - specifically, together they constitute a variable capacitor. Your body is the ground to which the hand side of this capacitor is connected.

What Don has spotted is that if you wind the wire round and round the drumstick it makes another electrical component - a coil, on the hand side of the antenna/hand capacitor but still part of the circuit. No doubt this will change the behaviour of the theremin a bit.

You thought you had a mad idea, but we are suggesting that you can tune your drumsticks like a radio.
Posted: 12/5/2008 4:20:02 PM

From: Escondido, CA

Joined: 2/6/2008

Just found the page with that minimum theremin schematic on it. It is as I feared, the basic CMOS gate variety.

This type of circuit is not nearly as sensitive (in the good way) as a heterodyne circuit, so it is no wonder you can't get it to work with an extended antenna.

You might have to separate them into 2 boxes and mount each one near the drum of interest to get them to work at all!

Experimenters used to make touch switch circuits using a very similar circuit. Basically ANY noise added to the antenna caused the thing to generate a pulse that latched a relay. They weren't all that good for that purpose either! Power brownouts, appliance motors turning on/off, or just about any other sort of noise caused these things to falsely trigger.

You will probably need some clever way to mute the output of those theremins when you don't want them to go off ... no free "appendages" for drummers to do that. Both hands and feet are in motion most of the time. Maybe some sort of "bump" switch you can hit with an elbow to mute/unmute them?


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