Gordon's Progress

Not intentionally, no. But who knows what the excitement, pressure and performance anxiety of such a wonderful weekend will do to a chap's cerebral cortex in the presence of all those ether waves?

As for having things up my sleeve, I'll leave that to Mark, as his area of expertise. My current technical endeavours will be revealed shortly....

I´m very curious about the experiments with your piezo transducers...

eagerly awaiting it...

cheers
arthur

Well, I tried feeding them with a line-level and a headphone-level output and successfully driving them to output sound. The ones I have are already glued to various surfaces, the most acoustically useful in this case being a biscuit tin lid. Ideally I would try some other surfaces, but I don't want to break the seal on what I've already done. It should work fine on anything with a natural resonance, I'd imagine, as it even came through reasonably clearly on a simple block of wood. Line level is only 1V, and these things can handle 30V peak, so I'm guessing that if I plugged it into an amp I'd get a louder result - what came out was clearly audible, but not loud. Our PA is in storage at the moment so I can't verify this easily, but according to the specs they should be able to output up to 90dB.

I didn't bother trying to record this, as it doesn't really prove anything.

@Arthur - I'm not sure how well these would drive something big enough to affect the theremin's playing area - maybe a metal ruler or similar (which we know works from Gordon's earlier trials). I suspect that the noise level generated by something able to do this would make it difficult for the performer (and audience) to concentrate on the theremin itself!

So, not terribly conclusive - they do work, but perhaps not quite the ultimate cheap panacea we'd like. I will be getting some more in the future, though. Handy little fellows.

Well, if you want a big fat actuator that is accustomed to the sort of voltages that a theremin generates, there's an electromagnetic one all wired up and hiding inside that old amp that's gathering dust in your garage.

I would think that all you have to do is strip away all the excess stuff like the cone and the mesh on the front and affix a long stick that can be attached to different test objects to communicate the vibrations of the actuator to them.

Alternatively - if one chamber makes a quiet sound, how many would you need to make a loud sound. It could look quite good on stage, you playing the theremin in front of a vast array of biscuit tins! Or drainpipes of different lengths. My physics is a bit rusty - that would establish a standing wave in a pipe when you hit it's resonant frequency or some multiple of it, yes?

Also, are you minded to try it on anything that is intended to be musical - an acoustic guitar for example?

Arthur - speaking of mechanical feedback loops and self-playing instruments, I found this when I typed "resonant chamber" into Google.

http://www.youtube.com/watch?v=l1hqF9nqabQ&v3

Oh yes, I've got one of those resonant chambers sitting in my garden shed somewhere... ;-)

I suspect the 'knackered bass speaker' method is probably the way to go, as you suggest.

Not so sure about sitting behind a pile of biscuit tins though. I like the drainpipe idea - you could have an array of pipes cut to a harmonic series or bass progression, so that as the theremin hit certain frequencies they would be boosted. I have a function like that (MIDI tuneable resonator) on my Quadraverb, which I never really explored as it wasn't great for guitar, but I've never tried it on theremin... must have a look at that.

As for the acoustic guitar - that was the first thing I did to test the transducers' effectiveness - stick it onto my old classical guitar. Worked a treat. The principle is the same as used by much more expensive acoustic guitar pickups. That's partly the reason I'll be getting some more!

Gordon, i love that crab guitar with the little Kuka-Robot arms... where can i buy it :-)

J_D and Gordon did you do experiments with electric feedback glitch in the pitch antenna field ?
Maybe something like a second antenna (say a mirror of the pitch oscillator)... I can imagine how it looks... the wizard stands in front of the theremin with his wand creating heavy resonances ...

Hope you (and the Mrs.) are holding up well.
All the best with HOUK!
It's an astounding effort.

Holding up very well, thank you.

Current mood: hot and ambitious.

(From Ambitious by Wire, from The Ideal Copy (http://www.wireviews.com/lyrics/the_ideal_copy.html).)

[i]When it's cold I feel cold
When it's hot I feel ambitious
Fit for a princess
Hot on the heels of an angel
Are you hot? Are you hot?
Are you hot? Are you hot?
Are you hot? Are you hot?
I feel ambitious[/i]


.

all the best this week
keep hot and ambitious
can't wait for the reports back.