Using the output of one audio node to modulate the value of an AudioParam is super easy... just use .connect
to connect the node to the AudioParam!
For example, to create a sawtooth wave with vibrato:
var saw = context.createOscillator(),
sine = context.createOscillator(),
sineGain = context.createGainNode();
//set up our oscillator types
saw.type = saw.SAWTOOTH;
sine.type = sine.SINE;
//set the amplitude of the modulation
sineGain.gain.value = 10;
//connect the dots
sine.connect(sineGain);
sineGain.connect(saw.frequency);
hi! and which one you connect to the audioContext.destination?