cello theremin

[ouwerocker]

I would like to build me a digital version of the fingerboard-or cello-theremin,
but can't find any information on the internet.
There is a lot of info about the "normal" theremins, but nothing about the technical
background, specialy the ribbon construction, of the cello theremin.
Could anyone help me further with schematics, construction tips, etc., ?

Thanks in advance
ouwerocker@hccnet.nl

[lohk]

As far as I know there is no fingerboard theremin, because a theremin is an "air" instrument, you probably mean a kind of trautonium. But neverheless contact the guys from the theremin center in moscow (no URL at hand, you will find it with google). They know everything about theremins, they should help you further.

Klaus

[ouwerocker]

there is for sure a cello teremin, have a look at sthe site of the theremin enthusiast's club,
http://typhoon.he.net/~enternet/teci/cello/cello.html

[lohk]

Thanks for the link, but this is definitly not a theremin, although it may have been build by Leon Thermen himself. It works with the variable resistance of a plastic conductive board.

[sauuuuuce]

Uh......The beach boys used a version of the fingerboard thingy in Good Vibrations. Worrks kinda the same way as the "real" one from what I could understand from the know burnt out Brian Wilson interview I watched in a Music History class

[Bunger Mulkin]

A theremin uses two RF oscillators, one tuned by an antenna (which is why you just have to get your hand near it and not touch it) and amplifies the beat (difference) frequency. Before modern tech, they were futzy. They still are.

Another technique for a similar sound (which I think was the 'Beach Boys' thingie, and is also the cello theremin) is a ribbon controller. Moog made one for their modular synths as a standalone box, a couple feet long, by about 4 inches high and 4 inches deep. If there are any left in playable condition, they have a generic control voltage output that can be made to control analog synths, or, through a CV-toMIDI box, most any MIDI device.

There were some earlier (30's or so) keyboard instruments with something similar. PAIA, the cheerfully cheesy electronic music kit company, used carbon-impregnated plastic (kind of like antistatic bags, but more conductive) played with a metal pin, for a ribbon-like thing on a handheld battery-powered synth.

The good ribbon controllers have a metal band suspended above the resistive ribbon, so they can trigger when you push down, like a keyboard.

They can be made at home, but it is a more advanced project. Find a piece of conductive plastic that you can measure the resistance with an ohmmeter (1K to 1MEG probably could be made to work, but the pink antistatic stuff won't, and conductive foam will work, but not for long) and then scrounge up a circuit from an old analog synth keyboard.

The easiest way to build a 'digital' version would be to build an analog ribbon controller, then buy a CV-to-MIDI box, and use the controller to run a standard synth.

Since the nature of the thing is unquantized (that is to say, analog and not digital) pitch, building it digitally may be unnecessarily complicated. How about interfacing a laser measuring device to MIDI gear?

If all you want is untuned whoopy noises, there are lots of ways. I have seen two-foot-long slide pots in surplus electronics catalogs. Would you settle for a trombone controller instead of a cello?