User Manual

User's Guide Fireface UC © RME

10.3 Known Problems

If a computer does not provide sufficient CPU-power and/or sufficient USB-bus transfer rates,

then drop outs, crackling and noise will appear. Such effects can be avoided by using a higher

buffer setting/latency in the Settings dialog of the Fireface UC. Furthermore PlugIns should be

deactivated temporarily to make sure they do not cause these problems.

More information can be found in chapter 31.3.

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 UC

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 UC. They all have to be in sync. Else a

periodically repeated noise will be heard.

Fireface UC supports ASIO Direct Monitoring (ADM). Please note that not every program sup-

ports 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 UC supports both MME MIDI and DirectMusic MIDI. It depends on the used application

which one will work better.

11. Using more than one Fireface

The current driver supports up to three Fireface UC. 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

Slave, 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.

The driver takes care of the numbering of all Firefaces, so that it doesn't change. The unit with

the lowest serial number is always 'Fireface (1)'. Please note:

• If the Fireface (1) is switched off, Fireface (2) logically turns to the first and only Fireface. If

Fireface (1) is switched on later, the numbering changes and the unit becomes Fireface (2)

immediately.

• The driver has no control on the numbering of the WDM devices. Therefore it might happen

that the WDM devices (2) are mapped to unit (1), especially when switching on more Fire-

faces during a Windows session. A reboot with all Firefaces already operational should

solve this problem.

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.