Technical information

Apollo Software Manual Chapter 12: Device Drivers 184
Chapter 12: Device Drivers
Apollo Drivers Overview
The Apollo device drivers are the low-level software files that instruct the computer’s op-
erating system on how to communicate with the Apollo hardware. The drivers are loaded
during system startup so that whenever Apollo is connected, the device is ready to ac-
cept instructions from the OS. Apollo’s drivers control Apollo’s audio interface, Console,
and UAD-2 functionality.
Core Audio
Apollo’s audio drivers use the Core Audio APIs. Apollo’s normal (non-DSP) audio inter-
face features are simply seen as a Core Audio device; therefore any Core Audio-compliant
software can use Apollo for audio I/O.
UAD Mixer Engine
The Console application and Console Recall plug-in don’t actually communicate directly
with Apollo. Instead, they communicate with the UAD Mixer Engine, which is the central
software hub for all Console and Console Recall functionality. The UAD Mixer Engine be-
haves as a server for Apollo’s internal DSP mixer that runs in the background, so Console
does not have to be open for Apollo to function.
The UAD Mixer Engine is a system-level application that is automatically launched dur-
ing system startup and is always running during normal operation. The UAD System
Menu is its only interface, which can be accessed from its blue “UA diamond” icon in
the OS X Menu Bar (at upper right of screen).
Driver I/O Complement
The specific inputs and outputs that are available to the DAW depends on the active
configuration. The I/O complement changes at high sample rates and when multi-unit
cascading. The specific I/O complements can be customized in the Core Audio Panel.
Default I/O values are listed in the Driver I/O Tables in this chapter.
Driver Names and Numbers
Apollo’s drivers describe all I/O channels by name and number, but what is actually dis-
played in the DAW’s I/O assignment lists depends on each particular DAW. Names are not
displayed by all DAWs (e.g., Ableton Live), or the driver name display mode may need to
be changed in the DAW (e.g., Apple Logic Pro).
Virtual I/O
Apollo’s device drivers carry various virtual (software only) input and output channels in
addition to those directly associated with the hardware inputs and outputs. The virtual
channels consist of all of Apollo’s bus outputs (the main monitor mix and all channel
send mixes) and Console’s virtual inputs. Virtual I/O facilitates highly flexible signal rout-
ing via the DAW. See “Virtual I/O” on page 169 for details about this feature.