User Manual

HARDWARE INSTALLATION
39
SETUP FOR MULTIPLE INTERFACES
It is possible to connect multiple MOTU interfaces
directly to your host computer through multiple
USB (and Thunderbolt) ports. However, there are
several disadvantages to using any of these direct
connection schemes:
■ The audio interfaces will not be clocked to one
another and may be susceptible to drift, unless you
use external word clock connections (if available).
You are better off using the AVB network
connections shown on pages 36-38. In this setup,
the interfaces are very tightly synchronized with
each other (measured in pico seconds) through
their network connections.
■ You will not be able to route audio directly from
one audio interface to another. You are better off
using the AVB network connections shown on
pages 36-38, which allows you to route audio
streams (hundreds at a time) directly among
interfaces with near-zero latency.
Connecting multiple interfaces using
Thunderbolt
If you have other MOTU interfaces with
Thunderbolt connectivity (828es, 1248, 8M, 16A,
112D, 624 or 8A) and your host computer has two
or more Thunderbolt ports, you can connect one
interface to each port, either directly or at the end
of a Thunderbolt daisy chain (on either port or
both ports).
Connecting multiple interfaces using
Thunderbolt and USB
Another way to operate multiple interfaces on the
same host computer is to connect the first
interface to a Thunderbolt port and the second to
a USB 2.0 (or 3.0) port.
Multiple interfaces and USB
When connected through USB, the 8pre-es
operates as a USB 2.0 device, even when
connected to a USB 3.0 port. USB 2.0 provides
enough bus speed for several USB 2.0 devices, but
due to the high-performance requirements of the
8pre-es for real-time operation and low latency
timing, we recommend the following:
■ Do not connect more than two units to your
computer’s USB 2.0 (or 3.0) ports.
■ When two units are connected with USB 2.0,
don’t connect other USB 2.0 or 3. 0 devices, such
as external hard drives.
■ For best results, establish clock synchronization
with other interfaces connected to the same
computer. You can use word clock, optical or AVB
to achieve clock synchronization.
Multiple AVB Ethernet audio interfaces
When operating 8pre-es as an AVB Ethernet audio
interface (see “AVB Ethernet audio interface
setup” on page 36), multiple AVB audio interfaces
can be connected using a MOTU AVB Switch (or
any 3rd-party AVB switch), and the Mac can see
all of them through their AVB connection. For
example, you could connect an Avid S3 console to
the Mac, and then connect a MOTU 8pre-es to the
S3’s extra network port (which is a built-in
switch). The Mac can see both 8pre-es and S3 for
audio I/O. For best results in this scenario, be sure
to use macOS 10.11 (El Capitan) or later. See
“Syncing multiple AVB audio interfaces connected
to a Mac” on page 51.
Mixing and matching audio interfaces
You can mix and match MOTU audio interfaces.
For example, you could connect an 8pre-es
through Thunderbolt and another MOTU audio
interface, such as the Stage-B16, through USB 2.0.