EMU_CHAN_LFOVAL2
emu_wrptr(sc, ch, EMU_CHAN_LFOVAL2, 0);
emu_wrptr(sc, v->vnum, EMU_CHAN_LFOVAL2, 0x8000);
emu_wrptr(sc, v->vnum, EMU_CHAN_LFOVAL2, 0x8000);
emu_wrptr(sc, ch, EMU_CHAN_LFOVAL2, 0);