//Effect
SynthDef(\vib, {|out=0,gate,in|
    var sig;
    var env;
    sig = In.ar(in,2);
    sig = sig*SinOsc.kr(8,0,0.5,0.5);
    ReplaceOut.ar(out,sig);
}).add;

~bus = Bus.audio(s,2);
~group = Group();
~vib = Synth.tail(~group,\vib,[\in,~bus]);

//Source
SynthDef(\ping, {|out=0,gate=1|
    var sig;
    var env;
    env = EnvGen.ar(Env.asr(0.01,0.1,0.5),gate,doneAction:2);
    sig = SinOsc.ar(262);
    sig = sig*env;
    Out.ar(out,sig);
}).add;

n = NodeProxy.audio(s,2);
n.play(out:~bus,group:~group,addAction:\addToHead);//DOESN'T PAN
n.play(out:0,group:s);//WORKS
n[0] = Pbind(\instrument,\ping);
n[1] = \filter -> {|in| Pan2.ar(in[0],MouseX.kr(-1,1))};