FOS

A first order filter section UGen. Filter coefficients are given directly rather than calculated for you. The formula is equivalent to:

out(i) = a0 * in(i) + a1 * in(i-1) + b1 * out(i-1)

'''Warning:''' there are bugs when the coefficients are modulated

===Examples===

// same as OnePole
play {
 val x = LFTri.ar(0.4) * 0.99
 FOS.ar(LFSaw.ar(200) * 0.1, 1 - x.abs, 0.0, x)
}

// same as OneZero
play {
 val x = LFTri.ar(0.4) * 0.99
 FOS.ar(LFSaw.ar(200) * 0.1, 1 - x.abs, x, 0.0)
}