Patching Yamaha's Formant Synthesis on an analog

[Ricko]

Yamaha's patent on their formant synthesis method expired yesterday. US4422362A

It is basically a fixed-frequency sine slave oscillator synched to a master oscillator driven by the KCV. The slave can be phase modulated either by a sine out of the master, or the sine out of a second fixed-frequency slave oscillator.

So it adds synch to the PM/FM picture.

It can be patched up on analog modular, if you can get CV access to the saw-to-sine converter of the VCO, which is not normal ou-of-the-box functionality.

KCV -> VCO MASTER -> synch VCO SLAVE saw -> ADDER -> SAW TO SINE -> OUT

plus either
VCO MASTER sine -> VCA -> ADDER
or
VCO MASTER -> synch VCO SLAVE 2 sine -> VCA -> ADDER