Orban Optimod-AM 9400, Operating Manual, Page: 77 / 295

OPTIMOD-AM DIGITAL INSTALLATION
2-25
d) Skip to step (G).
F) Calibrate using Program.
[Skip this step if you are using Tone to calibrate the 9400 to your stan-
dard studio level — see step (E) above.]
a) Verify E
XT
AGC is set to NO .
Refer to step 1 on page 2-23.
b) Feed normal program material to the 9400
Play program material from your studio, peaking at the level to which
you normally peak program material (typically 0VU if your console uses
VU meters).
c) Adjust the AI R
EF
(VU or PPM) control to make the 9400’s AGC meters
indicate an average of 10 dB gain reduction when the console’s VU meter
or PPM is peaking at its normal level.
If the
AGC
gain reduction meter averages less than 10 dB gain reduction
(higher on the meter), re-adjust the AI R
EF
(VU or PPM) to a lower level.
If the
AGC
gain reduction meter averages more gain reduction (lower on
the meter), re-adjust the AI R
EF
(VU or PPM) to a higher level.
G) When finished, reset
E
XT
AGC
to
Y
ES
if required (e.g., if that was its setting
prior to setting AI R
EF
(VU or PPM) level).
Refer to step 1 on page 2-23.
5. Adjust Right Channel Balance.
[Skip this step if the channels are already satisfactorily balanced.]
[

3 dB to +3dB] on right channel only, 0.1 dB steps
Adjust the R C
H
B
AL
control to achieve correct left/right channel balance.
This is not a balance control like those found in consumer audio prod-
ucts. This control changes gain of the right channel only. Use this control
if the right analog input to the 9400 is not at exactly the same level as
the left input. Be certain that the imbalance is not caused by one pro-
gram source, but is instead introduced through distribution between the
console output and 9400 input. This adjustment is best accomplished by
playing program material that is known to be monophonic or by setting
the mixing console into mono mode (if available).
It is always better to correct the problem in the transmission chain caus-
ing the imbalance instead of using the
R C
H
B
AL
control, which is really a
“band aid” for misalignment elsewhere in the system.
This control affects the balance of both the analog and digital processing
chains. If a given chain is in a
M
ONO
mode, you will not be able to see the
effect of this control on that chain. However, if you are in M
ONO
L+R
mode, the control will still adjust the right channel’s contribution to the
L+R sum.