code: function( _time, endLevel ) {
        if( isNaN( endLevel ) ) {
          endLevel = 1
        }
  
        var time = Audio.Clock.time( _time ),
            decay = new Audio.Core.ExponentialDecay({ decayCoefficient:.05, length:time }),
            //ramp = Mul( Sub(1,decay), endLevel )
            line = new Audio.Core.Line( 0, endLevel, time )
            
        this.amp = line
        
        future( function() { this.amp = endLevel }.bind( this ), time)
        
        return this
      }
docs: stop : function() { if( this.seq ) this.seq.stop() }, start : function() { if( this.seq ) this.seq.start() },