RME Audio Babyface User Manual - page 2
RME Tech Info Babyface Class Compliant
2
Background information on Class Compliant operation of the Babyface
1. History and general remarks
The Babyface has not been developed with stand-alone mode and iPad in mind. Therefore using
these two new modes require some special attention on how to deliver power to the Babyface.
In general an iPad delivers only about 20 mA to external devices. Connecting the Babyface, which
would run on USB bus power, will therefore throw up an error message on the iPad that the attached
device is not supported or draws too much current. Additionally the available current is far from what
the Babyface needs (500 mA).
Therefore in Class Compliant mode connected to an iPad the Babyface needs to be operated with an
external standard power supply, like the ones provided by RME ( 6 to 12 Volts and around 1 A).
The Babyface features automatic power on/off for the external power socket, steered by the presence
of USB power. To avoid the mentioned error message when trying to use the Babyface with the iPad,
make sure to connect all items in the right order: first connect the CCK with the Babyface, then plug it
into the iPad – and the Babyface will start without that error message on the iPad. The long version:
Connect Babyface to an external power supply, connect the USB cable to the BF, connect the CCK to
this USB cable, then plug the CCK into the iPad.
Connecting the CCK first into the iPad, then the USB cable (the Babyface) into the CCK will prevent
operation with the error message that the device needs too much power!
For stand-alone mode use USB bus power instead of the external power supply. Simply plug the USB
cable into any suitable USB power supply (like the charger for iPhone or iPad).
Since firmware 200 the Babyface operates in three different modes: driver-based USB 2, stand-
alone mode, and Class Compliant mode.The latter describes a standard that is natively supported
by operating systems like Windows, Mac OSX and Linux. No proprietary drivers are required, the
device will be directly recognized when CC mode is activated. Obviously, native features will be limited
in comparison to those provided by the RME driver set. For example there will be no (Total) Mix and
no effects.
The Babyface provides the iPad with the professional analog I/O connections it lacks. Superb
microphone preamps, in addition to professional balanced line outputs, and a hi-power headphone
output that also excels with high impedance headphones. Plus gain and level adjustments, SPDIF and
ADAT input and output, at up to 96 kHz and 24 bit. And of course a Sysex-capable MIDI I/O.
Note that since iOS 5 multichannel recording is supported, and since iOS 6 multichannel playback as
well. At this time only djay and Auria support more than one stereo output, others are expected to
follow soon.