message: Envelope uses Signal not TimelineSignal
diff: -define(["Tone/core/Tone", "Tone/signal/TimelineSignal",
  +define(["Tone/core/Tone", "Tone/signal/Signal",
  "Tone/signal/Pow", "Tone/type/Type", "Tone/core/AudioNode"], function(Tone){
  "use strict";
  @@ -81,7 +81,7 @@ define(["Tone/core/Tone", "Tone/signal/TimelineSignal",
  /**
  * the signal
  - * @type {Tone.TimelineSignal}
  + * @type {Tone.Signal}
  * @private
  */
  this._sig = this.output = new Tone.Signal(0);
  