swissonic aD 96, Руководство пользователя

Страница: 12 / 22

The level meters of the AD96 were designed to sup-
port the user throughout the recording process: It
helps accurately set the recording level before record-
ing (using the high-resolution -15…0 and -25…-10
scales for lineup), monitor the level during recording
(using the high dynamic range –60..0 scale), and
ensure that no or limited clipping occurred (by check-
ing the overs counter after the recording).
The level meters use high-accuracy digital peak
detectors, and format the output according to the
front panel setting. With all settings, the leftmost LED
works as a channel active indicator, lit whenever the
signal exceeds -60 dBFS, while the rightmost red LED
works as an over indicator, lit when clipping occurs.
When using the three metering modes, each LED
lights when the peak signal level exceeds the level
written next to it. The thresholds are accurate to
0,1 dB.
An overs counter is maintained by the unit at all times.
Whenever the clipping limit is exceeded, the overs
counter is incremented. When the overs mode is
selected, the contents of the overs counter is dis-
played on an exponential scale; for one over a single
led will light, for two (21) two leds will light, while for
1024 ( 210) eleven leds will light. The 14 leds allow
the display of values in the range 0…213 = 8192.
When more than 8192 overs are detected, all leds
will light. The over counter is cleared when the unit is
powered up, and whenever the cal button is pressed.
The normal sequence of operations for recording will
be as follows: first, route a calibrated tone to the
AD96 inputs. Select the -25…-10 scale, and adjust
the level on the driving device until the LED corre-
sponding to the desired level (e.g. -20 dBFS) just
begins to light. Then select the normal (-60…0) scale
for monitoring the recording and press Cal to reset
the overs counter (and ensure maximum performance
of the ADCs). Start recording. At the end, select the
overs mode and check the numbers. If just 2–3 LEDs
are on, things are probably ok, but if more than a few
light, the recording level was clearly too high.
AD96 can work with either internal or external clocking.
Each mode of operation was designed to respond
to specific demands. When you use a single AD96
unit, that needs not be synchronous with another
equipment, the best performance is obtained using
the internal clock mode.
Level Meters
Clocking
13