Wc Ratio; Lock Indication; Cal Mode Indicator - Apogee DA-16X User Manual

DA-16X – User's Guide
Navigating the Front Panel -
Parameters 3-7 are displayed in the Clock Window, as indicated at the top of this page.
3) CLOCK SOURCE – This parameter determines the clock source of the DA-16X, and may be set to INTernal crystal,
WC input, or to the digital INPUT (as selected by the INPUT parameter).To use Optical input as a clock or input
source, the ADAT 1-8 input must be connected first in precedence. When AES input is selected as a clock or input
source, all inputs are scanned until a valid input is detected; this input is utilized as the clock source.
4) SAMPLE RATE - When the CLOCK SOURCE is set to INTernal , the Sample Rate display indicates the frequency
of the internally generated clock, and may be set to all standard sample rates between 44.1 and 192 kHz. When the
CLOCK SOURCE is set to either WC or
INPUT, the display indicates the sample
rate of the DA-16X as a result of locking
to the selected source; the sample rate
cannot be set by the user.
5) WC Ratio – This parameter determines
the ratio between the word clock Input/
Output frequency and the unit's sample
rate. Figure 2 indicates the resultant
DA-16X sample rate given a specific WC
Frequency Ratio setting and word clock
input frequency. Likewise, the word clock
output frequency may be determined given a specific WC Ratio setting and DA-16X sample rate. This parameter
should be used to adjust the DA-16X word clock I/O to accommodate the requirements of specific digital systems.
For example, to configure the DA-16X to lock to a 48kHz word clock input and run at a sample rate of 192kHz, set
WC Ratio to WC fs/4.
6) Lock indication – These LEDs indicate the Lock status of the DA-16X's C777 clock. Two levels of lock precision
are displayed, Wide and Narrow. When the Narrow LED and Lock "exclamation point" are lit, the DA-16X has locked
to the selected CLOCK SOURCE in such a way to ensure the highest quality D-to-A conversion. If the Wide LED
or only the upper section of the Lock exclamation point lights, the stability of the clock source is questionable, and
should be verified.
Thanks to SureLock, Apogee's intelligent clock continuity algorithm, the DA-16X will output a stable clock signal
even if the selected CLOCK SOURCE is interrupted. When SureLock is engaged, the arrow section of the Lock
exclamation point flashes to indicate a loss of the clock source, while the Narrow LED and blue point light solidly to
indicate a stable clock output.
7) CAL mode indicator – This LED indicates that either Global or Channel CALibration mode is enabled, and that the
digital to analog conversion level may be calibrated. Global CAL allows the calibration of all 16 channels simultane-
ously, while Channel CAL allows calibration of individual channels. Global CAL mode is enabled by scrolling through
the 7 front panel parameters until the CAL LED flashes; "global Cal" will scroll across the Sample Rate display. Once
enabled, all 16 analog output levels may be adjusted by one of three operations:
• Press and Hold UP to raise the analog output level and DOWN to lower the level;
• Press and release UP or DOWN to modify the analog outputs +-.01 dB;
• Quickly tap UP or DOWN twice (think of a double mouse click) to modify the analog outputs +- 1.0 dB.
This double press function may be used to quickly jump from a "house" reference level to another
reference level in precise 1 dB steps.
3 4 5
6 7

WC Ratio

Setting
Figure 2
continued
44.1kHz 48kHz
WC x1: 44.1kHz 48kHz
WC /2: 88.2kHz 96kHz
WC/4: 176.4kHz 192kHz
Resultant DA-16X Sample Rate
5
APOGEE ELECTRONICS
Word Clock I/O Frequency
88.2kHz 96kHz
88.2kHz 96kHz
176.4kHz 192kHz
176.4kHz 192kHz
176.4kHz 192kHz
"Lock"
exclamation
point