This thread is for the benefit of classical thereminists considering getting an Electro Harmonix Talking Machine effects pedal, following Peter Pringle's demonstrations of its use to make music remarkably similar in tone to a tenor opera singer.
The first point to note is that the Talking Machine effect is only a starting point. Much of the similarity stems from the player playing in the style of an opera singer.
Secondly, it is unlikely that you will achieve exactly the same voice as Mr Pringle - the sound of the theremin he used is unique, and the sound of the theremin has a large bearing on the sound produced by the Talking Machine. Rather you have the opportunity to find your own personal theremin voice, just as every singer has a unique voice.
The Talking Machine performs best when presented with a sound which is rich in harmonic content. The sound produced by the etherwave is not particularly rich in harmonic content. Increasing the brightness of the theremin sound will increase the Talking Box effect, and altering the waveform will also alter the range of sounds that can be produced by the Talking Machine.
If you are finding that the effect is still not pronounced enough for your taste, you can increase the harmonic content of the sound from the theremin by conditioning it with another effects pedal placed before the Talking Machine. There are a great variety of ways to increase harmonic content, but guitar distortion and fuzz pedals are appropriate here.
There are a massive number of such pedals, each one claiming its own unique sound and superiority over other pedals. None of them claim particular suitability for theremin+Talking Machine usage. So this is your opportunity to try out a selection of them at a local music shop, and/or owned by musician friends, and find the one that most pleases you. This is probably best done after becoming familiar with the operation of the Talking Machine, which is a fairly complex pedal, with a great many options with varying degrees of applicability to classical theremin usage.
One thing you will discover is that many of these pedals (certainly the selection that I have tried) have settings which are unusable as the combination of the distortion or fuzz pedal followed by the Talking Machine leads to a lot of hiss when the theremin is muted. This limits the range of sounds that it can produce, and hence the range of tones that you can select from.
This limitation can be overcome by inserting the distortion or fuzz pedal in the effects loop of the theremin. An effects loop is a way of inserting an effect into the middle of the theremin circuit, after the oscillator but before the volume of the sound it produces is varied by the volume loop part of the circuit. At the time of writing, only Subscope theremins are available with prefitted effects loops. Etherwave theremins are not.
I had my Etherwave Standard fitted with an effects loop by Thierry Frenkel, and he has told me that he is happy to offer the same modification to other etherwave owners. (** Thierry ** please could you post your preferred means of contact for this service.)
I should note that an effects loop can be put to other uses than quieting pedals that are noisy when they should be silent. Some pedals are equipped with a noise gate which mutes the pedal (and hence hides any hissing) when the sound received by it drops below a certain level. This is terrible for theremin usage, as it becomes impossible to bring the sound up smoothly from silence. This does not occur when the pedal is in the theremin effects loop, as it always receives a sound from the theremin oscillator, so the noise gate never cuts in.
Putting distortion and fuzz pedals in the effects loop can also improve the quality of the sound produced. (Here I differentiate between a change in the tone and an improvement, which is a change akin to the difference heard when playing the same record on a better sound system.) Certainly it improved my fuzz pedal, particularly in the higher frequencies, reducing screechiness and making more of the settings for the fuzz pedal acceptable to me. I am not sure why this is, not being an electronics expert.
Note that pedals that rely on changes in the volume of a sound for parts of their behaviour will not display those behaviours whilst in a theremin effects loop.
There is rather more to the effects loop modification that Thierry made to my etherwave than I have described so far.
One unrelated benefit of this more sophisticated modification is that it makes a perceptible improvement to the tone of the theremin in ordinary operation.
(Thierry did not burden me with a detailed technical explanation of why this is, but I understand it is because the volume control and the waveform shaping circuits of the etherwave are both contained within a single chip, which is not optimal and leads to some degrading of the sound. As the modification requires a second such chip to be installed the two functions of volume and waveform can be allocated to separate chips, so this degradation does not occur.)
The modification works like this. The constant volume sound from the theremin's oscillator is split into two separate paths. One goes through the directly to the volume and waveform circuits and comes out of the audio socket of the etherwave.
The other path leads to a new audio out jack socket - this is where one would connect the "in" socket of a distortion pedal. The "out" socket of the pedal would be connected to another new socket an audio in socket, where the sound goes into the theremin and through a new volume and waveform circuit, separate from the original one, but sharing the same volume loop and waveform and brightness knobs as the original volume circuit.
This new volume/waveform circuit leads to a third new socket, another audio out jack socket, where the sound processed by the pedal in the effects loop comes out, and which varies in volume according to the player's proximity to the volume loop.
One relevant advantage of this more complex system is that both the altered tone and the unaltered etherwave tone are available at the same time and can be mixed together after the distorted tone has been further processed by the Talking Machine, giving the opportunity to moderate the effect and give it more or less of a theremin-like sound as desired. Typically one would achieve this using a mixer. (See this thread for why having a small mixer is a good idea anyway.)
One final point about Thierry's modification is that all three audio out sockets (the original one, the constant volume one and the new one after the volume circuit) have associated volume controls, so that the maximum volume of any of them can be reduced. This is beneficial for increasing the range of guitar pedals that can be used with the etherwave, as some guitar pedals do not perform correctly with the audio levels produced by the etherwave, which are significantly higher than the volumes produced by guitars.
It also means that in the absence of a mixer (*) to combine the two outputs as described above, or to control their mix without turning away from the theremin, one can turn the output volume knobs to adjust how much of each sound is heard.
(*) I do not have one to hand to test this, but I believe that a simple Y connector could be used to combine the two signals, given that the mix can be controlled with the output volume knobs.
There are other uses for this modification which are probably better suited to experimental than classical players. You can wire things up in all sorts of odd ways!
