I've just had a go at adding a synthio based mode to yesterday's Dub siren (see https://v.basspistol.org/w/pS4PrN9Wjo5eFP4hqFSpYr).

The switch now sets the siren to sample mode in its left position and to synth mode in the middle position. I may add another synth mode in the future.

The big knob on the left sets the LFO frequency of the siren, while the encoder to its right now selects the waveform, from ramp up, sine, saw and square.