Theremin simulator

New version (v1.22) of Theremin Explorer is avalible now. Download page is here.

The new version incorporates the ‘frequency pulling’ effect. The magnitude of this effect is controlled by the ‘Coupling: Dead zone’ parameter. When saving parameters to a file, this corresponds to the line ‘Fcoupling=’.

The simulation assumes that there is no hysteresis effect (the lock range is equal to the hold range, and the approach to the synchronization point is ‘soft’). For basics refer to topic. 

In reality, the hold range is always larger than the lock range, and synchronization can occur slightly earlier – a ‘hard jump.’ This is due to the oscillator’s increased sensitivity to noise and interference in the immediate vicinity of the synchronization region.

I wonder how this will affect the curves.

In the figure below, the black line represents the Etherwave musical scale without accounting for the coupling effect (as if the oscillators were completely decoupled):

The orange curve shows the effect of adding coupling, but with the Pitch control left unchanged. Note that the zero-beat point has moved closer to the antenna. The Pitch control was then adjusted to restore the original position of the zero-beat point (red line).

Is the coupling an improvement or not? It’s a complex question. On one hand, the length of the linear portion in the mid-frequency range has increased. This is due to a reduced sensitivity of the instrument to hand movements (i.e., the octave length has increased – it’s now around 10 cm versus 8 cm). On the other hand, the non-linearity of the bass range has drastically increased (the slope of the curve is steeper).

Similarly, for the Korolyov's (2003) theremin:

I think that overall, it’s a matter of personal preference.

"On one hand, the length of the linear portion in the mid-frequency range has increased. This is due to a reduced sensitivity of the instrument to hand movements (i.e., the octave length has increased – it’s now around 10 cm versus 8 cm)."  - ILYA

IMO, reducing the pitch field sensitivity without significantly impacting linearity makes for an easier to play instrument and is therefore a noble goal.  And substantially reducing the sensitivity makes for an entirely different instrument.  I reduce mine to roughly 1/2 of "normal" analog Theremin sensitivity which allows me to easily play standing up without a brace or chair, and breathe, squirm, etc. while doing so.  This of course precludes "normal" aerial fingering technique, but with heavily reduced sensitivity it seems less necessary?  There is so much analog expectation surrounding the Theremin, which of course is to be expected, but it's been rather bewildering for this developer to deal with.

ILYA, a bit of the artwork is missing, but your sim works in Linux Mint!

[EDIT] ILYA, could you perhaps add a "linearity" graph to your sim which shows the derivative (slope, sensitivity) of the response?  It's a bit hard seeing how linear it is and the level of sensitivity on the response graph.

"could you perhaps"

That makes sense. I should try that. But if all else fails, there’s a function to export the curve’s data points to a text file, which can then be analyzed in Excel.