({
  var in, chain, out;
  in = PlayBuf.ar(1, b, loop:1);
  chain = FFT(LocalBuf(2048), in);
  chain = chain.pvcalc(
    2048, {|mags, phases|
	    [mags.reverse, phases.reverse];
    }
  );
  chain = PV_BinShift(chain, shift:-320);
  out = IFFT(chain);
  [out, out];
}.play(s);
)