RME Tech Info Babyface Class Compliant
6
4. Supported Inputs and Outputs
In Mac OS X, either the first two or all channels will work, depending on the choice in the Audio MIDI
Setup. The playback signal of channels 1/2 can be copied to outputs 3/4 by the Babyface onboard
mixer.
When connected to an iPad, the analog mic/line input 1 works with mono apps, inputs 1 and 2 with
stereo apps (both dual mono and stereo), and up to 8 inputs with 8-channel applications like
MultiTrack DAW and Music Studio. Garage Band supports all 10 inputs, but only two at a time. Auria
can record all 10 inputs simultaneously.
Playback will use analog outputs 1 and 2, or even more channels if the app supports such operation.
The Babyface onboard mixer can copy the output signal 1/2 to outputs 3/4, SPDIF and ADAT, for
easier monitoring (Copy mode).
In Class Compliant mode the default clock mode is AutoSync at 44.1 kHz. The Babyface (and with it
the iPad) will be synchronized to an external digital sample rate if there is a valid digital input signal.
With a wrong sample rate heavy audio noise will occur. Without an SPDIF or ADAT input signal the
Babyface enters master mode and uses the sample rate set by Mac OS X or iOS (the app in use). The
Babyface can be set to fixed Master mode as well, but the set sample rate is ignored, as the iPad (the
current app) controls the sample rate value.
While the MIDI I/Os will send and receive Sysex messages, not all apps are ready to do this. For
example MIDI Monitor and AC-7 do not support Sysex at this time. The app Midi Tool Box can be
used to verify that the Babyface is working correctly, and the problem lies somewhere else.
In stand-alone mode, the unit operates as AD- and DA-converter. The clock modes are the same as in
CC mode, but here the chosen sample rate is indeed used by the unit. To recap what AutoSync
means:
- Without further configuration and no digital input signal, it will default to 44.1 kHz internal sample
rate.
- When receiving a digital input signal in SPDIF format, it will sync itself on the external sample rate,
from 32 kHz to 192 kHz.
- When receiving a digital input signal in ADAT format, it will sync itself on the external sample rate,
from 32 to 48 kHz. Double Speed mode is automatically set when receiving an ADAT signal from other
RME devices. Otherwise the setting has to be performed manually (LEDs 8 or 9, see below).
