[1_person]

Assuming this is the DRSSTC design I am familiar with it uses solid state switching with audio modulated interruption. The drive waveform is pulsed, the resonant frequency would typically be not significantly above the audible frequency range, and there's typically a few cycles of attack with active drive then several cycles of decay without active drive. There will consequently be a decent amount of smearing of fast notes and harmonic distortion but the interruption frequency shouldn't be sliding or anything.