code: public synchronized void setVolume(float gain)
  	{
  		if (currentVolume != gain)
  		{
  			currentVolume = gain;
  		    if (sourceLine!=null && sourceLine.isControlSupported(FloatControl.Type.MASTER_GAIN))
  		    {
  		    	FloatControl gainControl = (FloatControl)sourceLine.getControl(FloatControl.Type.MASTER_GAIN);
  		        float dB = (float)(Helpers.getDBValueFrom(gain));
  		        if (dB > gainControl.getMaximum()) dB = gainControl.getMaximum();
  		        else
  		        if (dB < gainControl.getMinimum()) dB = gainControl.getMinimum();
  	        	gainControl.setValue(dB);
  		    }
  		}
  	}
docs: Set the Gain of the sourceLine
  @since 01.11.2008
  @param gain