Front Panel
13
(18) Digital Out Level -
These LEDs indicate the signal level of the A/D converters. Each of the eight
A/D channels has its own two-segment level indicator.
The lower LED illuminates green when the incoming signal is between -37 dBFS and -6 dBFS. This LED
displays the signal level continuously (it does not have peak/hold functionality).
The upper LED is a two-state indicator. When the incoming signal is between -6 dBFS and -1 dBFS, the
LED is yellow; the LED is red when the signal exceeds -1 dBFS. This LED has a peak/hold
implementation; signal peaks are “held” for 90 ms.
(19) Lock -
When the 4-710d is locked (synchronized) to a clock source, the LOCK indicator glows
green. The indicator glows red when the clock is not locked. The clock is always locked when the
Sample Rate knob
(
#17 on page 12)
is set to an internal sample rate. For the clock to be locked
when the clock source is external, a valid clock signal must be present at the rear panel word clock
input (see note above).
In order for the 4-710d to detect and lock to a valid external word clock, the frequency of
the incoming word clock must be within ±3% of any of the supported sample rates (44.1,
48, 88.2, 96, 176.4, or 192 kHz). If the frequency of the incoming work clock is not within
±3% of a supported sample rate, the LOCK indicator will glow red, the WORD CLOCK OUT
will be driven at 48 kHz, and the digital outputs will be driven at 48 kHz and muted.
The clock must be locked for proper A/D conversion.
If the clock won’t lock when the Sample Rate knob is set to W/C (external word clock),
verify that the external device is connected to the word clock BNC input and is transmitting
a valid clock signal.
The 4-710d cannot lock to an external device that is set to slave to the 4-710d!
