Using External Clock; I/O Settings - E-Mu 1616 PCI Owner's Manual

4 - The PatchMix DSP Mixer
The Session
The System Settings include the following:
• Internal/External Clock
• Sample Rate
• External Clock Source
(ext. clock only)

Using External Clock

Whenever you are using any digital I/O such as ADAT or 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 embedded into a data stream such as S/PDIF or ADAT.
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 be extinguished 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.

I/O Settings

You can set the level (-10dBV or +4 dBu) for each pair of analog outputs and the input
gain setting for each pair of analog inputs.
An output setting of +4 provides the most output and is compatible with professional
audio gear. Balanced output cables provide a +6dB hotter signal than unbalanced cables
when used with balanced inputs. Do NOT use balanced cables unless your other gear
has balanced inputs. See
information.
Comparison of -10dBV & +4dBu Signal Levels
Consumer
(unbalanced)
{ + 6 dBV
Clipping -->
Headroom
+ 2 dBV
-10 dBV
0 dBV = 1V RMS
An input setting of -10 is compatible with consumer audio gear and works best with low
level signals. (-10dBV is approximately 12dB lower than +4dBu.) Choose the setting that
allows you to send or receive a full scale signal without clipping.
Setting correct input and output levels is important! You can measure the level of an
input by inserting a meter into the first effect location in the strip. Adjust your external
equipment outputs for the optimum signal level. See
for details.
32
Selects between internal or external word clock source
as the master clock source for the system
Selects the sample rate when using internal clock.
Your choices are: 44.1kHz, 48kHz, 88.2kHz, 96kHz,
176.4kHz, 192kHz.
Select from: ADAT, or S/PDIF as an external sample clock
source.
"Cables - balanced or unbalanced?"
Professional
(balanced)
+20 dBu }
=
+8 dBu
=
+4 dBu
=
-8 dBu
0dBu = .777V RMS
in the Appendix for more
<-- Clipping
Headroom
"To Set the Input Levels of a Strip"
E Note: if set to
"External" without an
external clock present,
PatchMix DSP defaults to
the internal 48kHz clock
rate.
f Input too weak?
Use -10 Input setting.
Output too weak?
Use +4 Output setting
Creative Professional