Known Problems; Using More Than One Fireface Ufx - RME Audio Fireface UFX User Manual

10.3 Known Problems

If a computer does not provide sufficient CPU-power and/or sufficient USB or PCI* bus transfer
rates, then drop outs, crackling and noise will appear. Raising the buffer size in the Settings
dialog of the Fireface UFX helps in most cases. It is also recommended to deactivate all PlugIns
to verify that these are not the reason for such effects. Further information is found in chapter
33.3.
*The note on PCI is not an error in this manual: very often FireWire controllers are connected to
the PCI bus. Therefore the same problems known from PCI audio cards can occur with Fire-
Wire audio interfaces as well. Further information is found in chapter 33.4.
Another common source of trouble is incorrect synchronization. ASIO does not support asyn-
chronous operation, which means that the input and output signals not only have to use the
same sample frequency, but also have to be in sync. All devices connected to the Fireface UFX
must be properly configured for Full Duplex operation. As long as SyncCheck (in the Settings
dialog) only displays Lock instead of Sync, the devices have not been set up properly!
The same applies when using more than one Fireface UFX - they all have to be in sync. Else a
periodically repeated noise will be heard.
Fireface UFX supports ASIO Direct Monitoring (ADM). Please note that not all programs sup-
port ADM completely or error-free. The most often reported problem is the wrong behaviour of
panorama in a stereo channel.
In case of a drift between audio and MIDI, or in case of a fixed deviation (MIDI notes placed
close before or behind the correct position), the settings in Cubase/Nuendo have to be
changed. At the time of print the option 'Use System Timestamp' should be activated. The Fire-
face supports both MME MIDI and DirectMusic MIDI. It depends on the used application which
one will work better.

11. Using more than one Fireface UFX

The current driver supports up to three Fireface UFX. All units have to be in sync, i.e. have to
receive valid sync information (either via word clock or by using AutoSync and feeding synchro-
nized signals).
•
If one of the Firefaces is set to clock mode Master, all others have to be set to clock mode
AutoSync, and have to be synced from the master, for example by feeding word clock. The
clock modes of all units have to be set up correctly in the Fireface Settings dialog.
•
If all units are fed with a synchronous clock, i.e. all units show Sync in their Settings dialog,
all channels can be used at once. This is especially easy to handle under ASIO, as the
ASIO driver presents all units as one.
Note: TotalMix is part of the hardware of each Fireface. Up to three mixers are available, but
these are separated and can't interchange data. Therefore a global mixer for all units is not
possible.
In real-world an operation of more than one Fireface UFX makes no sense and is therefore not
actively supported by RME. Each further unit would lead to problems on the USB and FireWire
bus, caused by the high number of channels. The UFX has been developed as monitor control-
ler and – not extendable – digital mixer. It makes more sense to connect external converters to
the ADAT I/Os of the UFX, adding up to 16 channels of analog record and analog playback.
26
User's Guide Fireface UFX © RME