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Sample Rate
Converter
Navigate to the
Setup / Sample Rate Converter
menu:
Here the
Input Rate
(digital sampling rate) of the AES program
input is automatically displayed in the upper box if a digital in-
put is connected to the DAVID IV. The sampling rate of the AES
digital output is selected in the lower box.
Press
the jog wheel
to enable the
Output Rate
selector, and
turn
the knob to pick a
fixed output rate. The Output Rate may also be set to follow
the incoming digital signal if the digital input is selected under
Setup / Audio Input
.
FRONT-PANEL HEADPHONE JACK
The headphone jack on the front panel monitors the broad-
band-limited output of the peak limiter. This is a ‘flat’ monitor
point that does
not
reflect action of the 15kHz low-pass filter
and adaptive pre-emphasis for FM transmission. The volume
control next to the jack adjusts only the headphone volume.
COMPOSITE MULTIPLEX OUTPUT
The DAVID IV has two independent outputs for the compo-
site/MPX (multiplex) signal. These outputs include the S (L+R),
S’ (L–R), 19kHz Stereo Pilot and optional RDS subcarrier com-
ponents that comprise the FM baseband signal.
Navigate to:
Setup / Stereo Generator
:
Confirming
Pre-Emphasis
FM broadcasting imparts high-frequency pre-emphasis to the
program audio signal in transmission, and the FM receiver then
provides the complementary de-emphasis. The time constant
of the pre- and de-emphasis networks is determined by geo-
graphic location. The Americas (Western Hemisphere) have
standardized on a 75-microsecond curve, and Europe has cho-
sen 50-microseconds. Other parts of the world have opted for
one or the other of these, so make sure you know what setting
is the proper one for you location before proceeding.
Содержание David IV
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