Clock Modes - Synchronization - RME Audio Babyface Pro User Manual

9.9 Clock Modes - Synchronization

In the digital world, all devices must be either Master (clock source) or Slave (clock receiver).
Whenever several devices are linked within a system, there must always be a single master
clock.
A digital system can only have one master! If the Babyface Pro's clock mode is set to 'Inter-
nal', all other devices must be set to 'Slave'.
The Babyface Pro utilizes a very user-friendly, intelligent clock control, called AutoSync. Se-
lecting Optical as Clock Source, the system constantly scans the digital input for a valid signal.
If any valid signal is found, the Babyface Pro switches from the internal quartz (Clock Mode –
Current Internal) to a clock extracted from the input signal (Clock Mode – Current ADAT or
SPDIF). The difference to a usual slave mode is that whenever the clock reference fails, the
system will automatically use its internal clock and operate in clock mode Master.
AutoSync guarantees that record and record-while-play will always work correctly. In certain
cases however, e.g. when the inputs and outputs of a DAT machine are connected directly to
the Babyface Pro, AutoSync may cause feedback in the digital carrier, so synchronization
breaks down. To solve this problem switch the Babyface Pro clock mode to Master (Clock
Source – Internal).
In some situations changing the clock mode can not be avoided. Example: A CD player is con-
nected to the SPDIF input. Try recording a few samples from the CD and you will be disap-
pointed - few CD players can be synchronized. The samples will inevitably be corrupted, be-
cause the signal from the CD player is read with the clock from the Babyface Pro, being out of
sync. In this case, the Clock Source should be set temporarily to Optical In.
RME's exclusive SyncCheck technology (first implemented in the Hammerfall) enables an easy
to use check and display of the current clock status. Input Status indicates whether there is a
valid signal (Lock, No Lock) for the optical input, or if there is a valid and synchronous signal
(Sync). In the field Clock Mode the clock reference is shown. See chapter 26.1.
Under WDM the Babyface Pro will
(has to) set the
Therefore the error shown to the right
can occur. A stable signal with a
sample rate of 32 kHz is detected at
the ADAT input (Sync), but Windows
audio had been set to 44100 Hz
before. The red color of the text label
signals the error
prompts the user to set 32000 Hz
manually as sample rate. Under ASIO
the audio software sets the sample
rate, so that such an error can not
happen. If the input sample rate is
different then there will be no Sync indication.
With RME's AutoSync and SyncCheck, finally anyone can master this common source of error,
previously one of the most complex issues in the digital studio world.
sample rate.
condition, and
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