How can the timbre be radically altered in the chain?

Coalport said: Newcomers to the theremin who are first-time buyers usually base their decision to purchase on the sound of the instrument. Rarely do they ever hear the sound live. They usually go by YouTube recordings or mp3's. They are unfamiliar with all the other more important considerations such as linearity, configuration, etc. and generally have little or no experience with the way timbre can be radically altered in the chain between the instrument and the speaker.

Well I don’t talk about linearity these days, so if the sound and the voice are two separate things…

With my first pedal a “Talking Machine” I learned the theremin sound can be distinctly brightened and still sound almost natural in the lower range without any reverb effect.

Observing the TM it creates a complex wave shape without reverb. Reverb seems to add an unnatural scab on the wave form edge which is often used as a BandAid for bad sound.

I am not picking at the scab; But I would not want to make it the dominant effect in my final voice, maybe just an added whisper.

What would be a recommended second pedal or box "to purchase" that adds brightness to the normally dull transistor simple wave shape, but in the mid/upper range without adding a reverb or echo effect?

Christopher

"What would be a recommended second pedal or box to purchase that adds brightness to the normally dull transistor simple wave shape, but in the upper range without adding a reverb echo effect?"

You might try a harmonic sweetener, which can be as simple as a high pass filter followed by a clipper, then a mixer:

http://circuitdiagram.net/harmonic-sweetener-guitar-effect.html

Better designs might have steeper filters, and some kind of clipper muting when the input amplitude is small (I've never built one).

"What would be a recommended second pedal or box to purchase that adds brightness to the normally dull transistor simple wave shape, but in the upper range without adding a reverb echo effect?"

Adding "brightness" equates to either (a) adding (creating) harmonics which are not present in the signal, and / or (b) controlling the level of these higher harmonics.

In a "dull" signal, there are generally low levels of higher harmonics - if one has, for example, a near sine wave, putting this signal through a HPF will not result in much amplification of the higher harmonics - in order to boost these harmonics, a lot of gain is required - and the unpleasant side effect of this is increase in noise.

One can distort waveforms - clipping produces (mostly) odd harmonics, half wave rectification produces mainly even harmonics - these are probably the easiest distortions to implement.. Mixing these distortions one can give control over the "brightness".

A parametric equalizer (or a graphic equalizer) is another useful tool - If this follows a mixer which takes the raw+squared+rectified signals, one can really achieve whatever degree of "brightening" one desires, and get rid of "harshness" which distortion can create.

Fred.

The perfect theremin sound is the sound you like best.

I have probably experimented as much as anyone to find that elusive timbre. I have even gone so far as to place a speaker inside a cello (no mean feat!) searching for that acoustic Holy Grail.

One of the problems with guitar pedals and FX is that they often tend to add noise - assorted buzzes, hisses and other distortion -  to your sound. Most devices including the Talking Machine, if they work at all, will only work within a specific range. For precision players, the TM will give you a surprisingly engaging tenor on its open "AH", but that is all. The other sounds are a bit clownish but fine if that is what you're looking for (Gordon Charlton used some of them very effectively in his "robot" video).

There are high end preamps that will do all sorts of wonderful things to both human voices and theremins. I use a MILLENNIA STT-1 but it is professional equipment and at close to 3000 bucks it is liable to be a bit expensive for most hobbyists.