Pitch Preview

Thanks for the input/advice, omhoge.

If I lived in the US I wouldn't hesitate to get Moog to add a pitch-preview for me; here in the UK I think it would be less straight-forward. Right now, I'm happy playing without it, and would probably prefer to avoid depending on it, except for finding the "starting note".

The more I think about it, the more an indicator light illuminating whenever you play an "A" seems like a good idea, (as long as it's designed to include lighting up for silent "A"s when the left hand is muting the volume antenna). I'm fairly sure that once I'd found a silent "A" I could then position my fingers up to a fifth above or fifth below fairly accurately, which should cover finding just about any "stating note".

I can't off-hand recall where I read about this indicator light on Clara Rockmore's theremin. I feel like I've read just about every page of every site about theremins lately ... but I'll trawl back through my browser history and track it down, then post a link to it. (Unless I imagined it!!!)

Thanks again!

You didn't imagine it. It's here (http://peterpringle.com/customtheremin.html).

:-)

@Thereminstrel:

If you want, feel free to contact me, I am in France and I could do the modification for you if you could send me your Etherwave in.

frenkel(dot)thierry(at)orange(dot)fr

Aha!

Thanks, GordonC ... I'd just tracked it down and come to post the link, but you beat me to it.

It seems such a useful little gizmo; I wonder why it hasn't been used in contempoary theremin design. Does anyone have any idea what the technical wizardry would entail? Something too complicated to be cost-effective ... or what? Could it be added to an exisiting theremin as a modification do you think? Or am I crazy thinking this is a good idea?

Thanks also, Thierry.

I may well do that. I'm most grateful for the offer. I think I'll wait a little while though; I'm still new to playing the theremin, and at this stage I fear that being seperated from it for a time might set my learning back a little. Once I feel a little more secure about my playing, it is certainly something I'd really like to get done.

Thanks!

Just for your info: I found a way to join the original pitch preview and headphone amp circuits suggested by Moog, so that you would get a 3,5mm stereo headphone plug, a knob for its volume adjustment and a switch which allows either pitch preview or "normal" (dependend on the volume loop) headphone operation.

You're welcome.

I'm not an electronics expert, but I imagine it's pretty straight-forward - I'm thinking band-pass filter and light bulb.

As to it's usefulness, I suspect that Mr Pringle got it right - it turns the theremin into a giant tuning fork for the rest of the orchestra. I can't really imagine hitting A0 then blind navigating to another note successfully - even for The Rockmeister.

GordonC, your idea with the band pass filter is theoretically right, but it would be too difficult to get precision and needed smallness of the bandwith at such low frequencies in the real world.

An easyer way (as most digital tuners operate) would be a pll circuit which compares the sound with a reference frequency.

But I agree with you that the usefulness of such a circuit may be questionable.

Maybe not A0, but it would not be much trouble for A440! You could even add a rotary switch to switch in different capacitor values for the other "standard pitches" orchestras use for A below middle C.

A state-variable filter should allow you to get the accuracy you need without the tight tolerances needed for a multiple feedback bandpass filter.

The 2 types of guitar tuners I have (a Seiko and a Korg) have a bit too much latency to be useful, so I am guessing that a DSP filter would probably be too slow in general.

Don

Thierry - That makes me wonder about the stability of Lev Theremin's circuit.

(Of course it doesn't need to be [i]exactly[/i] 440Hz (aka A440, the ISO standard (ISO16) for A4, not A0. Concert pitch. (*) Oops.) What matters is that everyone tunes to the same pitch.)



(*) Wikipedia. :-)