RME Audio Fireface 802, Руководство пользователя

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User's Guide Fireface 802 © RME 25
9.3 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 802 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
38.3.
*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 38.4.
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 802
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 802 - they all have to be in sync. Else a
periodically repeated noise will be heard.
Fireface 802 supports
ASIO Direct Monitoring
(ADM). Please note that not all programs support
ADM completely or error-free. The most often reported problem is the wrong behaviour of pano-
rama 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.
10. Using more than one Fireface 802
The current driver supports up to three Fireface 802. 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 802 might be difficult. Each further unit will
lead to problems on the USB and FireWire bus, caused by the high number of channels. It
makes more sense to connect external converters to the ADAT I/Os of the 802, adding up to 16
channels of analog record and analog playback.