Impulse

Chuck

Impulse i => BiQuad f => dac;
.99 => f.prad;
1 => f.eqzs;
0.0 => float v;

while( true ) {
  1.0 => i.next;
  Std.fabs(Math.sin(v)) * 4000.0 => f.pfreq;
  v + .1 => v;
  100::ms => now;
}

Stride

signal Phase { rate: 10 }
signal Frequency { rate: none }

Phase >> Sin () >> Abs () >> Level ( gain: 4000.0 ) >> Frequency;
Phase + 0.1 >> Phase;
ImpulseTrain ( frequency: 10 ) >> BiQuad ( type: 'LowPass' frequency: Frequency resonance: 2.0 ) >> AudioOut;

signal Frequency { rate: 10.0}
signal Phase { default: -0.1 rate: none}

Phase + 0.1 >> Phase >> Sin () >> Abs () >> Level ( gain: 4000.0 ) >> Frequency;
ImpulseTrain ( frequency: 10.0 ) >> BiQuad ( type: 'LowPass' frequency: Frequency resonance: 2.0 ) >> AudioOut;