theremins

[Arthur Harrison]

Travis wrote re: theremins:

>i'll hear your ramnblings quite gladly...i'll b up for making one of these
>beasts soon

I write:

Paul Perry and I were chatting about various theremin topologies,
of which there are many, and many more to come, for certain.

For many synth DIYers, the objective is to use Leon Theremin's concept
as a gestural controller for VCOs, VCFs, triggers, etc.  Of course,
the instrument can also be relegated to its original form as a stand-alone,
voiced entity.  This topology is often referred to as a "heterodyne"
theremin,
where two RF oscillators, one fixed and the other varying per hand-
capacitance, produce an audible beat frequency.  For those interested in
such a basic implementation, I humbly refer you to my recent article at:
http://home.att.net/~theremin1/SWTP.htm.

This is quite a nice little theremin which used the 1967 Louis Garner, Jr.
design
as a starting point.  Since many of the folks on this list have hardware
resources,
perhaps some of you will try it.

The nice thing about this design is that it only uses less than 10mA from a
standard 9v  battery, and will thus run for hours, and is highly portable.
I am planning  another theremin for web publication soon, and it will be
more
signal-processing oriented, e.g., will employ a "double-synthetic" topology
whereby the voice is a VCO, not the actual heterodyned signal.  This one
will
be readily adaptable for CV applications, and have some goodies like a
linearization circuit to even-out the pitch spatial relations.

In the meantime, I hope some of you will review the above mentioned, and
give
me some feedback!  If this theremin prompts enough response, I may make
some blank PCBs for distribution.

Art in thereminland


-----Original Message-----
From: Travis Endersby <travis at it.net.au>
To: Arthur Harrison <theremin1 at worldnet.att.net>
Date: Wednesday, December 09, 1998 5:26 PM
Subject: Re: theremin problems!


>i'll hear your ramnblings quite gladly...i'll b up for making one of these
>beasts soon
>
>ta
>trav
>
>On Wed, 9 Dec 1998, Arthur Harrison wrote:
>
>> Cool, Paul.
>>
>> (If anyone is interested in my theremin ramblings,
>> just let me know, and I"ll CC my rants to the list.)
>>
>> -Art
>>
>>
>> -----Original Message-----
>> From: Paul Perry <pfperry at melbpc.org.au>
>> To: Arthur Harrison <theremin1 at worldnet.att.net>
>> Date: Tuesday, December 08, 1998 9:55 PM
>> Subject: Re: theremin problems!
>>
>>
>> >Thanks Art! I feel much less lonely now!
>> >
>> >If nothing gets done on this soon, I might go to a digital approach,
>> >actually counting the pulses and working from that.. the figs seem to
work,
>> >just! (500KHz and a PIC)
>> >
>> >paul perry melb aust
>> >
>> >
>> >
>>
>
>