-- red_frik (f0)
let red tr n =
      let o1 = fSinOsc kr (tRand 0.3 5 tr) 0 * tRand 0 0.5 tr + tRand 0.49 0.56 tr
          o2 = fSinOsc kr o1 0 * tRand 0.3 0.6 tr + tRand 0.3 0.5 tr
      in rhpf n (tRand 0.3 3 tr) o2 * 0.1
    n = mceFill 2 (\_ -> brownNoise ar)
    tr = impulse kr 0.1 0
in red tr n * 0.1

-- red_frik (f0) ; monad
let red tr n = do
      r1 <- tRandM 0.3 3 tr
      r2 <- tRandM 0.3 5 tr
      r3 <- tRandM 0 0.5 tr
      r4 <- tRandM 0.49 0.56 tr
      r5 <- tRandM 0.3 0.6 tr
      r6 <- tRandM 0.3 0.5 tr
      let o1 = fSinOsc kr r2 0 * r3 + r4
          o2 = fSinOsc kr o1 0 * r5 + r6
      return (rhpf n r1 o2 * 0.1)
    red_frik_m = do
      n <- replicateM 2 (brownNoiseM ar)
      let tr = impulse kr 0.1 0
      red tr (mce n)
in uid_st_eval red_frik_m * 0.1