9
USING THE OCTOPRE
COMBO INPUTS
All eight analogue inputs use “Combo XLR” connectors. These accept male XLR connectors, TS
(unbalanced) ¼” jacks or TRS (balanced) ¼” jacks.
When you use an XLR connector, the preamp automatically configures gain and impedance to receive
microphone level signals. If using a ¼” plug, the preamp accepts balanced or unbalanced line level
signals. When you enable INST mode (Channels 1 or 2), the 1/4” input is optimised for an unbalanced,
high impedance signal.
LINE OUTPUTS
You can connect the line outputs of the OctoPre to the analogue line inputs of outboard
equipment (or any other device), to use it either as an analogue, 8-channel microphone preamplifier,
or as an analogue “break-out box” for ADAT signals when in ADAT>LINE mode.
The outputs are balanced; see [20] on page 7 for the pinout. Ready-made DB25-to-XLR or
DB25-to-jack breakout cables are available from professional audio suppliers.
DIGITAL OUTPUTS
Use the OPTICAL OUT ADAT port(s) [18] to connect the OctoPre to the ADAT input(s) of an
audio device using TOSLINK optical cable(s).
The ports can send eight channels of audio at 44.1 kHz or 48 kHz sample rate via a single optical
cable. At these sample rates, the two ports carry the same eight channels.
At 88.2 kHz or 96 kHz sample rates, each port sends four channels. The right-hand port carries
Channels 1 to 4, the left-hand port carries Channels 5 to 8; you need two TOSLINK cables to send all
eight channels.
At 176.4 kHz or 192 kHz sample rates, each port can transmit two channels. The right-hand port
carries Channels 1 and 2, the left-hand port carries Channels 3 and 4. The OctoPre is restricted to
four channels of digital audio at these sample rates; the outputs of Channels 5 to 8 are not available
via the ADAT ports.
Use the SAMPLE RATE switch [9] to select the sample rate frequency. It is essential the sample rate
selected on the OctoPre matches the sample rate set on the receiving digital device.
