message: the partials length is controllable by the partialCount
diff: @@ -330,6 +330,13 @@ export class Oscillator extends Source<ToneOscillatorOptions> implements ToneOsc
  } else {
  this.type = type + p.toString() as ToneOscillatorType;
  }
  + } else {
  + // extend or shorten the partials array
  + const fullPartials = new Float32Array(p);
  + // copy over the partials array
  + this._partials.forEach((v, i) => fullPartials[i] = v);
  + this._partials = Array.from(fullPartials);
  + this.type = this._type;
  }
  }
  