User Manual

INSTALLING THE 8PRE HARDWARE
16
CONNECT AUDIO INPUTS AND OUTPUTS
The 8pre audio interface has the following audio
input and output connectors:
■
8 combo XLR/quarter-inch analog mic/guitar/
instrument inputs
■ 2 balanced, +4 dB quarter-inch TRS main outs
■
2 pair of ADAT optical (“Lightpipe”) in/out
Here are a few things you should keep in mind as
you are making these connections to other devices.
Mic/guitar/instrument inputs
Connect a microphone, guitar or other similar
instrument to any XLR/quarter-inch combo jack
input on the rear panel. If your microphone
requires phantom power, move the 48V phantom
power switch on the front panel to the up position
(enabled). Use the trim knobs on the front panel to
adjust the input level as needed for each input. The
trim knob provides approximately 40 dB of gain.
Use the input level meters on the front panel
(labeled
Analog In ) to calibrate the level. These
meters register for both the XLR and TRS input.
If a line level signal is still too hot with the trim
turned all the way down, engage (flip down) the
20dB pad switch on the front panel.
Main outs
The main outputs serve as independent outputs.
The main out volume is controlled by the volume
knob on the front panel. Push the knob to toggle
between phone and main out volume control. In a
standard studio configuration, the main outs are
intended for a pair of studio monitors, but they can
also be used as additional outputs for any purpose.
Optical
The 8pre provides 8-channel digital input and
output at 44.1, 48, 88.2 and 96 kHz. The 8pre rear
panel provides two sets of ADAT optical
(“lightpipe”) connectors: an top row and a bottom
row.
Reminder: optical goes OUT to IN and IN to OUT.
Input and output are independent. For example,
you could connect ADAT optical input from your
digital mixer and connect the output to an audio
interface connected to your computer.
Optical operation at 44.1 or 48 kHz
When connected to an ADAT “lightpipe”
compatible device, the two optical connectors in
the top row provide eight channels of digital input
and output at 44.1 and 48 kHz.
In addition, when operating the 8pre at a 1x sample
rate (either 44.1 or 48 kHz), optical output is
duplicated on the second (lower) optical output.
This lets you send the 8pre’s 8-channel ADAT
optical output to two separate destinations in your
studio, if needed.
Optical operation at 88.2 or 96 kHz
When operating the 8pre at the 2x sample rates
(88.2 or 96 kHz), the top row of optical connectors
provides channels 1-4 (in and out) and the bottom
row provides channels 5-8 (in and out) when
connected to another optical device that supports
88.2/96 kHz optical sample rates.
When operating the optical ports at a 2x sample
rate, be sure to choose either Type I or Type II
operation, as explained in “Setting the 2x optical
mode” on page 29.
Using optical I/O when operating the 8pre as an
audio interface
When the 8pre is connected to a computer
(Figure 3-4 on page 18), these optical ports
provide digital input and output to and from the
computer.
Using optical I/O to operate the 8pre as an
8-channel expander
When the 8pre is not connected directly to a
computer via FireWire, the optical input is disabled
and the eight optical output channels mirror any
incoming signal on the 8pre’s eight XLR/TRS
!8pre Manual/Mac Page 16 Tuesday, October 12, 2010 5:52 PM