Table of Contents
Advertisement
change.
Push the
+4 dB
meter function switch
and
select the Peak
characteristic.
The indication on the meter will be
-6 dB.
Again,
the actual output level does not change.
Return the meter character-
istic to AVG (average) reading.
3.3.2
GAIN REDUCTION CHECK (Allow
15
minutes warmup).
Push the GR meter function switch.
The VU meter should read
0
VU since the limiting function
is
disabled
[the
Attack control
is
turned fully counterclockwise (CCW)3.
Turn
the
Attack control
ON;
gain reduction should be indicated.
Observe the tracking between the indicated amount of gain reduction
and the actual
change in output
(VU
)
level
as
measured with an
ex-
ternal meter.
The tracking should be within
±1
dB.
Selecting other compression ratios of the limiter will indi-
cate some gain reduction in each setting
,
however
the actual amount
will vary due
to the
different threshold sensitivities.
3.3.3
STEREO TRACKING
Apply
the same signal to both inputs.
Switch the meter
func-
tion
to GR, and,
with
the
mode switch
in the
A/B position, adjust
the Input controls until the same amount of GR
is
indicated on each
VU meter
—
for
example
-5 dB.
Select the +4 dB meter function
and
adjust the Output level
controls
for the
same indication on
both meters
—
for
example
0
VU.
Switch the mode switch
to
STEREO
and check the tracking
between
the
two meters
to
remain within
1
dB.
3.4
APPLICATION
3.4.1
CONTROL SETTINGS
Since all important
paremieters
of the Model 1178 are variable,
the instrument
is
flexible enough
to be used in
virtually all phases
of sound processing, from recording of
a
single track to reproduc-
tion
of the full
program material.
The limiter finds application
as a
creative instrument during production,
as
well
as a
device
for
automatic level control
and
protection against high amplitude
problems
.
There
is
no
single correct setting
of the controls; rather
experimentation
is
necessary
to find the
best combination
of
compression
ratio, attack and release time, and the amount of
gain reduction
for
the job at hand.
Experience will show that
the
dynammic parameters (attack and release
time)
have
a
stronger
effect on the character of the program material than the static
parameters (compression ratio
and
threshold).
-
12 -
Advertisement
Table of Contents
Troubleshooting
