Orban OPTIMOD 8685, Operating Manual

Page: 38 / 357

1-10
INTRODUCTION ORBAN MODEL 8685
Input/Output Configuration
In its base configuration, OPTIMOD 8685 simultaneously accommodates:
•
Digital AES3id inputs (5) and outputs (6).
•
Two analog monitor outputs.
•
A headphone output.
The 2.0 processors in OPTIMOD 8685 can be operated in either stereo or dual-mono
mode via the
2.0 P
ROC
M
ODE
control. In dual-mono mode, the channels operate in-
dependently (and have separate Loudness Controllers and Loudness Level Meters),
but the processing parameters that determine the “sound” of the processor are the
same on both channels.
Dual-mono or stereo mode is a global system parameter. You can change modes
manually, via the 8685’s GPI inputs, via 8685 PC Remote software, or via the 8685’s
built-in time-of-day automation. Further, the 8685 can be programmed to recognize
the “stereo” and “dual-mono” flags in the AES input bitstream and to switch modes
accordingly. It will also set these flags appropriately in its output AES bitstream.
Digital AES3id Inputs/Outputs
The digital input and outputs conform to the professional AES3id standard, which
calls for 75
Ω
coaxial cable terminated with BNC connectors.
The 8685’s AES3id connections are all internally terminated with trans-
formers that expect to see 75
Ω
. To interface AES3id to AES3 (110
Ω
bal-
anced) connections, we recommend using 75
Ω
/110
Ω
matching trans-
formers when cable runs are long. For short runs (10 feet or less), trans-
formers are usually unnecessary.
In the base configuration, there are five inputs (which carry 10 channels) and six
outputs (which carry 12 channels). In the optional HD-SDI configuration, there are
three inputs and three outputs. All inputs and outputs have sample rate converters
that allow operation at 32, 44.1, 48, 88.2, and 96 kHz sample frequency.
To ensure best control of peak modulation, operate the output at 48 kHz
or higher.
Level control of the AES3id inputs are accomplished via software control through
System Setup (see step 8 on page 2-27) or through PC Remote. Level control is one
of the many parameters contained in a Setup.
The output sample rate of each AES3id output can be locked independently to the
8685’s internal crystal clock, the sample rate present at its AES3id input, the sample
rate present at the 8685’s AES11id sync input, or 1x word clock.
The 8685 can apply J.17 deemphasis to signals applied to the digital inputs assigned
to the 2.0 processors. J.17 is a 6 dB/octave shelving preemphasis/deemphasis stan-