SynthDef(\invert, {arg buffer;

var in, chain;

// a sample signal (strong sin tone, little PinkNoise)

in = SinOsc.ar(440, 0, 0.4) + PinkNoise.ar(0.1);

chain = FFT(buffer, in);

chain = PV_Invert(chain);

Out.ar(0, [in, IFFT(chain) * 0.5]);

}).load(s);

s.boot;

s.sendMsg(\b_alloc, 0, 2048)

s.sendMsg(\s_new, \invert, 1000, 0, 1, \buffer, 0);