AETHERPHON, global theremin family

> Yes, however Philip keep careful notes and make each change one at a time.

Absolutely!

> The timbre modulation is likely the result of interference / coupling
> tendency between the oscillators.  So, if you completely isolated the
> pitch and volume oscillators (if such is possible) you might also
> loose the timbre modulation. A subtle tweak to the frequency of the
> volume oscillator might be enough to do the trick.

Probably.. My slant on these things, is not to try for that "magic"
config, but to make the front end very repeatable, and then introduce
the proper waveshaping on the output.