M-Audio Delta Audiophile 2496 Manual page 22

S/PDIF In stream.
NOTE: If "S/PDIF In" is selected as the master clock source, be
sure to supply a valid S/PDIF signal to the board's active S/PDIF
input. Otherwise, erratic timing and/or improper sample rates
will be experienced.
Once a master clock source has been selected, its synchronization status is
continually monitored and displayed below the master clock radio buttons. If
internal crystal is selected, the status display will always say "Locked." On the other
hand, if S/PDIF In is selected as the master clock source, the control panel will
display "Locked" only when a valid S/PDIF signal is detected. It will display
"Unlocked" when there is no signal at the S/PDIF input, or when the signal is corrupt
or invalid for any reason.
CODEC SAMPLE RATE: This section indicates the Audiophile's current sample
rate. The digital mixer, converters and digital ports are all locked to this sample rate.
If the Audiophile is currently in use by some software application, then this indicated
sample rate was set by the software application. Otherwise, this is the "idle" sample
rate that the Audiophile is using when not in use by software applications. The idle
sample rate is controlled by the "Reset Rate When Idle" checkbox on the Delta
Panel. When "Reset Rate When Idle" is not checked, the Audiophile simply retains
the last sample rate set by an application when the application discontinues use of
the Audiophile. When it is checked, the Audiophile will switch (if necessary) to the
selected sample rate whenever the Audiophile is not in use by an application.
NOTE: Because the digital monitor mixer runs at the sample rate
of the rest of the board, and because sample rate directly affects
frequency response, it may sometimes be desirable to keep the
sample rate at or above 44.1 kHz while using the monitor mixer.
This is accomplished by enabling "Reset Rate When Idle" and
selecting a sample rate of 44.1 kHz or greater.
The Delta Panel also allows you to lock the Audiophile sample rate to some specific
value, and only that value. This is accomplished by checking the "Rate Locked"
checkbox. When you lock the Audiophile sample rate, this will disallow any
application from setting the sample rate differently. If an application attempts to do
so, you will most likely see an error message. The default setting is to leave "Rate
Locked" unchecked.
S/PDIF SAMPLE RATE: When using S/PDIF In as your master clock, this section
tells the driver what the expected S/PDIF input sample rate is. The section is only
displayed when the board is set to use S/PDIF In as the master clock source. From
the list, select the sample rate closest to that of the S/PDIF input data. The sample
rate selected here will be the only sample rate available to the software applications.
Therefore, you must set your audio software application to this same sample rate or
else the application will display an error message.
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