A Theremin inside a guitar...

Posted: 4/3/2008 5:38:57 PM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

You might find this thread (http://www.thereminworld.com/forum.asp?cmd=p&T=2204&F=1) about the theremin cello interesting.

Welcome to Theremin World, Plankhead.

Posted: 4/3/2008 6:17:07 PM

From: Long Island, NY

Joined: 4/2/2008

Thanks for that thread. Though now that I know how the theremin cello works, I'm not so sure I want to replicate its method.

What I want to do is be able to take a cheap electric guitar I have laying around my house and convert it into a prototype. To replicate the cello's fingerboard, I'd likely have to build a new neck.

Ideally I'd like to simply be able to lay an antenna along the length of the neck and have the position of a finger on it be detected. Electronically, I'm not sure how to implement this.

If I'm being confusing, perhaps this diagram will explain exactly what my idea is:

Posted: 4/3/2008 7:14:09 PM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

OK, got the idea.

Antennas measure the distance your hand is from the antenna, not where you touch them. Google [i]ribbon controller[/i].

Alternatively, if you really want an antenna, here's a suggestion. Take a theremin with a plate antenna, such as the Art Harrison Minimum I notice you're asking about on another thread (the answer is, it's a major mod - better to start with a 2 antenna design) and attach a long, non-conductive pole (a rigid plastic cylinder) of the desired length to it, sticking straight up from the centre of the plate. To make it wearable, attach a belt to both sides of the enclosure and wear it as one might wear a sporran, with the pole projecting upwards at a convenient angle for sliding one's hand along the length of it to play the instrument.

I look forward to seeing it demonstrated on youTube.
Posted: 4/3/2008 9:11:07 PM

From: Long Island, NY

Joined: 4/2/2008


Now the big question: what 2-antenna design do I mod to use a ribbon? Can, say, a Theremax board be hooked up to a ribbon controller for pitch?
Posted: 4/3/2008 10:00:03 PM

From: Long Island, NY

Joined: 4/2/2008

One more thing: someone else I spoke to suggested an "inverted amplifier" for the volume control circuit to make the strumming feel more natural. Anyone see that as being practical?
Posted: 5/18/2008 8:57:12 PM

From: New Brunswick

Joined: 5/18/2008

wow, I was sitting listening to Portishead today and had this same idea. I was thinking of installing the theremin in the top horn of my jaguar, as there's already a cavity and a plate with controls
I'm pretty much wondering the same thing- will it work with interference from pickups etc.? It would be sweet to have the pitch on the bridge and the head of the guitar serve as the volume antenna or what have you
Posted: 5/18/2008 11:22:18 PM
RS Theremin

From: 60 mi. N of San Diego CA

Joined: 2/15/2005

A true theremin more often dictates her finicky needs to the designer while he tries to adapt his own ideas of what might be possible.

Combining a theremin with a guitar is like wanting to build a trombone into a guitar. These are two distinctly different instruments operating with different physics that will most likely interfere with one another. If the term theremin is being used loosely than an optical theremin approach could over come many of the design obstacles, then one might think controlling a carefully mounted optical tone oscillator. The volume control could then be a super bright LED on the end of the guitar neck that transmits an IR or Light tone modulated beam created by the guitars optical tone oscillator. This beam can sweep by a nearby remote optical sensor like a photo-transistor shielded from any stray lighting for perfect volume control. Overall this can be very simple in design if you have some basic construction and electronic experience.

Optical Tone Oscillator ( http://www.oldtemecula.com/theremin/rs-opticaltheremin/rs-opticaltheremin.htm)

FredM, I hope the best for you, as I live with numb feet and a keen understanding of your serious situation.

RS Theremin
Posted: 5/19/2008 3:58:33 PM

From: Escondido, CA

Joined: 2/6/2008

Ok ... here's a thought, but it might be a bit more work than you want to do.

If you can bring a wire up to each fret (this would necessitate routing a groove into the neck somewhere), you can use those connections for individual "touch switches". Those can select individual capacitors via FET switches in your tank circuit.

Yes this is complicated, but it might make a fun project.

On the other hand there are those Roland-equipped guitars that have a midi interface or the USB guitars. But then that is very far away from a theremin.


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