Javascript Recorder source webaudio

I have this code to record an audio source :

recordingstream=contextAudio.createMediaStreamDestination();
recorder=new MediaRecorder(recordingstream.stream);
source.connect(recordingstream);
  				
source.start(0,ndeb,nfin);
recorder.start();

width :

source.onended = () => {
     sourcEtat=0;
    recorder.addEventListener('dataavailable',function(e){
		  					 
   document.getElementById("renduWav").src=URL.createObjectURL(e.data);
			  				 
  document.getElementById("renderAudio").style.display="block";
    	recorder=false;
    	recordingstream=false;
  });
  recorder.stop();
};

This code record the buffer of the source but not the transformed source. How to record the output of source.start(…)

Sorry, Sorry. Just connect the last node on recordingstream, panner for me.