E-MU 0404 PCIe Digital Audio System OpMan - English - Version 2.10

4 - The PatchMix DSP Mixer
The Session
Session Settings
System Settings
Pressing the Session Settings button on the toolbar brings up the System Settings window
shown below. Click the tabs to select System or I/O options.
The System Settings include the following choices:
• Internal/External Clock Selects between internal or external clock source
as the master clock source for the system
• Sample Rate
• External Clock Source
(ext. clock only)
Selects the sample rate when using internal clock.
Your choices are: 44.1kHz, 48kHz, 88.2kHz,
96kHz, 176.4kHz, 192kHz
Select S/PDIF as an external sample clock source.
Note: if set to
“External” without an
external clock present,
PatchMix DSP defaults to
the internal 48kHz clock
rate.
Using External Clock
Whenever you are connecting two or more devices using digital I/O such as S/PDIF, one of the
digital devices MUST supply the master clock to the others. This master clock runs at the
system sample rate and can be distributed using a dedicated cable (word clock) or embedded
into a data stream such as S/PDIF. Common symptoms of unsynced digital audio include,
random clicks or pops in the audio or failure of the digital stream to be recognized. Always
check for the presence of the “LOCKED” indicator whenever you are using a digital
interface.
If an External Clock is interrupted or switched after the Session has been created (except
between 44.1k 48k), the “LOCKED” indicator will extinguish and PatchMix will attempt to
receive the external data. The two units are NOT sample locked however, and you should
correct this condition to avoid intermittent clicks in the audio.
22 Creative Professional