RME Audio ADI-2 Pro, User Manual

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User’s Guide ADI-2/4 Pro SE - v 1.0
29. General
The ADI-2/4 Pro SE operates in
Class Compliant mode (UAC 2.0), a standard that is natively
supported by operating systems like iOS, Mac OS X, Linux and Windows 10 (since 1709). No
proprietary drivers are required, the device will be directly recognized.
The ADI-2/4 Pro SE provides iOS devices with the professional analog I/O connections they lack.
Professional balanced and unbalanced line inputs and outputs, two Extreme Power headphone
outputs that excel with both high and low impedance headphones, extensive gain and level ad-
justments, AES, SPDIF and ADAT I/O connectivity, PCM record / playback at up to 768 kHz, and
DSD record/playback at up to 11.2 MHz (DSD256). An app like
Neutron can actually play files
with up to 768 kHz sample rate and DSD 256 natively via the ADI-2/4 Pro SE in Basic Mode
Stereo.
The ADI-2/4 Pro SE does not supply power to the iPad/iPhone. The latest Lightning to USB 3
Camera adapter from Apple includes a Lightning socket to connect the standard Apple power
supply, allowing to charge the i-device while it operates in Class Compliant mode with the ADI-
2/4 Pro SE.
30. System requirements

Any Apple iPad with at least iOS 6 or an iPhone with at least iOS 7

Apple iPad Camera Connection Kit or Lightning to USB adapter

iPad Pro: no active adapter, just a simple USB-B to USB-C cable or connector adapter
31. Setup
Connect the USB cable to the Camera Connection Kit/Lightning adapter/iPad Pro. Start the i-
device and plug the Kit/adapter into the i-device
’s socket. If everything works as expected, the
unit will be used for all audio I/O. Audio playback in iTunes will automatically be performed by the
ADI-2/4 Pro SE, using analog outputs 1/2 and 3/4.
Note: The i-
device’s volume control is inactive during USB operation.
32. Supported Inputs and Outputs
When connected to an iPad, the analog input 1 works with mono apps, inputs 1 and 2 with stereo
apps (both dual mono and stereo), and up to 6 inputs with multi-channel applications like
Multi-
Track DAW and Music Studio . Garage Band supports all 6 inputs, but only two at a time. Auria
and Cubasis can record all 6 inputs simultaneously.
Playback will use analog outputs 1 and 2, or even more channels if the app supports such oper-
ation, like Auria and Cubasis, which allow to use all 8 output channels when the device has been
set to CC-mode Multi-channel.
In Class Compliant mode the default clock mode is
Internal , and iOS typically sets 96 kHz or
higher. Any app can change / set the sample rate to a desired value, but not all apps include a
choice to select one. Setting the ADI-2/4 Pro SE (and with it the i-device) to slave mode by se-
lecting the AES or SPDIF input as clock source, the ADI-2/4 Pro SE will be synchronized to the
external digital sample rate. With a wrong external sample rate heavy audio noise will occur (use
of the SRC will help in specific cases). Without an external signal the ADI-2/4 Pro SE changes to
its internal clock, with the sample rate set by iOS or the app in use.