4069 theremin

Like that plunger trombone thing Fred.."doesnt look as nearly as crap as the Glasgow 'didital' theremin, LOL! ;-)"all theremins are 'digital' in that you play them with the fingers ie digits...a theremin joke... With metal 'rings' like these below

http://www.siamsky.net/VHD/ring20100107/DSC_2213.JPG

maybe one could get results similar to capacitive sensing with an electromagnetic type metal detector theremin...It would be cool playing a theremin with those kind of 'rings' LOL...But thanks Fred for your opinions I really appreciate it.

Fred's inductive trombone reminds me of a circuit in the LM3909 (LED flasher and all around versatile IC) application note, where the acoustic resonance of a speaker in a variable volume box sets the operating frequency.  Change the volume with a plunger and play a tune.  I've never built it but it is an intriguing concept.

Invis said: "maybe one could get results similar to capacitive sensing with an electromagnetic type metal detector theremin...It would be cool playing a theremin with those kind of 'rings'

Those finger tip adapters could be practical and add more visual theatrical flair to theremin playing, I think it could work. Longer fingers are often desired in a theremin pitch field so you could hold one octave in your hand without forward arm movement.

The nice thing about the standard theremin pitch field is its broad vertical height and adjustable depth. Musical notes are in a relatively fixed position and can be sustained. 

Fred said: "Every other method imposes limitations or reduces the options for the player."

I tried to use an optical volume control for years, it worked but lacked what I call fluidness in response and it had a narrow field of view.

(Ultra-Sonics... don't waste your time.)

I tried countless theremin tricks but she always led back home, there is something beautiful about the theremin.

The area that has me most intrigued today is oscillator coil interaction and wave shape influences. I once believed transistors were void of even harmonics or dominated by odd but learned that's a myth. I wonder if that is on my 13 myth thread ?

Christopher

"I tried countless theremin tricks but she always led back home" - Christopher

Yes - She always does seem to do that doesnt she !?  ;-)

Be warned, anyone who thinks she's easy! LOL - She will take you on a long and extremely expensive ride! - But boy - what a ride!  ;-)

Fred.

" I once believed transistors were void of even harmonics or dominated by odd but learned that's a myth. I wonder if that is on my 13 myth thread ?"

I dont think this utterly BS myth was specific to theremins - I think it was postulated / invented by tube worshipers to justify their claims that tubes were superior to transistors for audio.

Lest there be any doubt - there is absolutely no basis for this myth - the only time it might apply is if the transistors are overwhelmingly overdriven into saturation, so that whatever you shove into it produces a square wave out - and therefore will turn (almost) any input into a "odd harmonics only" output... But the same is true for tubes - except that they are not quite so easily saturated, and have more non-linearity close to "saturation" if I remember correctly (tube saturation occurs as the space charge at the cathode depletes I think..)

IJ - My condemnation of the "Glasgow" "theremin" is not because its "digital" (it isnt actually digital - its mixed signal..) my condemnation is simply because its crap!  ;-)

"Be warned, anyone who thinks she's easy! LOL - She will take you on a long and extremely expensive ride! - But boy - what a ride!  ;-)" - FredM

I'm just a noob at this, but the Theremin siren song seems capable of ensnaring the staunchest designer's boat onto the rocks.  It seems so simple, and everything's going fine until you try to improve things by making it a tiny bit more <insert some minor aspect here> which leads to <insert harrowing tale of woe here> ...

"I'm just a noob at this, but the Theremin siren song seems capable of ensnaring the staunchest designer's boat onto the rocks.  It seems so simple, and everything's going fine until you try to improve things by making it a tiny bit more <insert some minor aspect here> which leads to <insert harrowing tale of woe here> ..." - Dewster

"<insert harrowing tale of woe here>"

Its certainly not all "woe"..

In many ways, I wish I had been younger when I got on this "path" - If I had had the time and money to spend on theremin R+D (and if I had heard its "siren song") I think there could probably be no better way to learn "this kind" of electronics - it would have made me a much better engineer.

But (probably like most young engineers) I was into the "new stuff" - And it did serve me well - the "new stuff" is mostly what employers believe they want..

I think that the education obtained by working with the theremin is ideally suited to the highly paid areas of RF and also gives a great introduction (by extension) into areas like resonant power supplies and the like - These are areas I tried to avoid - but, when I was "forced" to take them on, caused me a lot of difficulty.. which is a shame, because there are only a handful of good engineers in this field, and they all earned in a day what I earned in a month!

When I was working in power electronics for electric vehicles, I had to employ one of these engineers on contract for a month (and paid £50k from a tight budget - not my money, thankfully ;) - I could now do the job myself, thanks to what I have learned from theremins in the last few years!

So - Young engineers.. Dont let my tales of woe put you off ! - There is a treasure-trove of understanding if you have the time and patience and determination, and push yourself to understand the weird things you see when you fiddle with theremins!

Fred.