SPDIF_SELECT
ucontrol->value.integer.value[0] = (snd_emu10k1x_ptr_read(emu, SPDIF_SELECT, 0) == 0x700) ? 0 : 1;
snd_emu10k1x_ptr_write(emu, SPDIF_SELECT, 0, 0x000);
snd_emu10k1x_ptr_write(emu, SPDIF_SELECT, 0, 0x700);
snd_emu10k1x_ptr_write(chip, SPDIF_SELECT, 0, 0x700); // disable SPDIF