Transitions from atonal supersaw chorus to a chord with a clear pitch correlation are performed fluently and with certain grade of repeatability.
Using the phenomenon of avalanche breakdown is quite an unsustainable mode of transistor operation: applying reverse polarity voltage thru collector-emmiter path causes deterioration of the semiconductor. Oftentimes reverse breakdown voltage & current are not documented and may vary even among different batched of same transistor series.

On the other hand the advantages of this circuit are its vivid simplicity, graspable by absolute beginners and relative abuse-resistance of modern BJTs. Suitable for starting with additive synthesis and experiencing basic oscillator principles, this circuit delivers legitimate variable frequency pulses with sawtooth-like rises and steep falls utilizing a single transistor.
LMNC’s impressive demo shows the scalability potential of this circuit. The KiloDrone is built manually on manufactured PCB’s and makes a very solid impression for a project of such proportion. It would be interesting to see how far further this idea could be taken with modern SMT fabrication services.
Further reading:
https://en.wikipedia.org/wiki/Relaxation_oscillator
https://en.wikipedia.org/wiki/Avalanche_transistor
Kerry Wong: BJT in reverse avalanche mode