ess_setmixer
ess_setmixer(sc, 0x71, 0x2a);
static void ess_setmixer(struct ess_info *sc, u_int port, u_int value);
ess_setmixer(sc, 0x78, ess_getmixer(sc, 0x78) & ~0x03);
ess_setmixer(sc, 0x7a, ess_getmixer(sc, 0x7a) & ~0x80);
ess_setmixer(sc, 0x74, len & 0x00ff);
ess_setmixer(sc, 0x76, (len & 0xff00) >> 8);
ess_setmixer(sc, 0x78, 0x10);
ess_setmixer(sc, 0x7a, 0x40 | fmtval);
ess_setmixer(sc, 0x70, spdval);
ess_setmixer(sc, 0x72, ess_calcfilter(spd));
ess_setmixer(sc, 0x78, ess_getmixer(sc, 0x78) | 0x03);
ess_setmixer(sc, 0x78, ess_getmixer(sc, 0x78) & ~0x10);
ess_setmixer(sc, 0, 0); /* reset */
ess_setmixer(sc, 0x60, l);
ess_setmixer(sc, 0x62, r);
ess_setmixer(sc, preg, (l << 4) | r);
ess_setmixer(sc, rreg, (l << 4) | r);
ess_setmixer(sc, 0x1c, recdev);
ess_setmixer(sc, 0x71, 0x2a);