Mackie d8b v3 Service Manual page 27

POWER
ON
SYSTEM
<
RESET
UNMUTE
MUTE
As the console powers up, the D/A converters are muted on the CODEC board and the TAPE cards.
This prevents noise form being heard or recorded on the Analog lines.
When the system has finished booting correctly, the all-important UNMUTE signal is sent from the DSP
board to this little circuit, and so the D/A converters are unmuted and ready. So, if the DSP is not booted
working correctly, the UNMUTE may not be sent, and the audio will remain muted.
If RAP music is attempted, and the words "hip 'n a hop" or "bip 'n a bop" detected, then the D/A
converters are muted automatically. Its only fair.
System Boots DSP >
POWER
OFF
TIME
27
MUTE