Inovonics DAVID IV 719 N, Инструкция по установке и эксплуатации

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advantage with care. A conservative figure, the factory default
value of 1.0dB, is generally benign.
TEST OSCILLATOR
The DAVID IV sports a built-in test tone generator (audio oscil-
lator) that may prove helpful in setting up the DAVID IV, for
troubleshooting, or in verifying overall system performance.
The Test Oscillator is accessed through
+ Test Osc/Proof
at the
bottom of any
Processor
Webpage, or from the front-panel
Setup
menu.
Pre and
Post Modes
Off
is the default selection for normal operation of the DAVID
IV. For testing, tones may be applied ahead of the processing
stages:
Pre
, or following all processing:
Post
.
The test tone is a monaural source applied in the digital do-
main to both the left and right inputs of the processing chain.
Frequency (Hz):
may be varied between 20Hz and 20kHz in
10Hz steps, and the
Level (dB):
of the tone set in 1dB steps be-
tween –60dBFS and 0dBFS.
DAVID IV
Gain Structure
A –20dB, 400Hz test tone applied at the input to the processing
chain (
Pre
) will bring the AGC to 0dB (unity) gain. –20dBFS is a
nominal internal “zero-VU” reference level at this point and re-
fers to the program’s average level.
Gain associated with normal processing action is expected to
drive the processor to full 0dB or 100%-modulation output.
Thus when this same –20dB tone is applied after processing
(
Post
), it drives the composite/MPX output only to the 10%
point on the
MPX
level meter, and to –20dB on the
L
and
R
OUTPUT
meters. Readjust
Level (dB):
to reach a desired output
value.
The virtual sliders may of course be used to set and
Level (dB):,
but you may find it easier to highlight and overtype the num-
bers in the boxes to the left of the sliders. Alternatively, click
on the slider knob and use keyboard cursor keys to step up and
down.
Processor
Bypass
or ‘Proof’
Processor Bypass:
gives the choice of
Operate
, normal DAVID IV
operation, or
Proof Mode
. In ‘Proof,’ the input and output level
controls remain functional, but all dynamics-processing utili-
ties are fixed at unity gain with a flat-frequency characteristic.