User`s guide
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User's Guide Fireface UC © RME 
10. Operation under ASIO 
10.1 General 
Start the ASIO software and select ASIO Fireface USB as the audio I/O device or the audio 
driver. 
Fireface UC supports ASIO Direct Monitoring (ADM). 
The Fireface UC supports both MME MIDI and DirectMusic MIDI. 
10.2 Channel Count under ASIO 
At a sample rate of 88.2 or 96 kHz, the ADAT optical input and outputs operate in S/MUX mode, 
so the number of available channels is reduced from 8 to 4. 
At a sample rate of 176.4 and 192 kHz, the ADAT optical input and outputs operate in S/MUX4 
mode, so the number of available channels is limited to 2. 
Note
: when changing the sample rate range between Single, Double and Quad Speed the num-
ber of channels presented from the ASIO driver will change too. This may require a reset of the 
I/O list in the audio software. 
Single Speed  Double Speed  Quad Speed 
Fireface UC Analog 1 to 8  Fireface UC Analog 1 to 8  Fireface UC Analog 1 to 8 
Fireface UC SPDIF L / R  Fireface UC SPDIF L / R  Fireface UC SPDIF L / R 
Fireface UC AS 1 to 2  Fireface UC AS 1 to 2  Fireface UC AS 1 to 2 
Fireface UC ADAT 3 to 4  Fireface UC ADAT 3 to 4  Fireface UC ADAT 3 to 4 
Fireface UC ADAT 5 to 6  Fireface UC ADAT 5 to 6  Fireface UC ADAT 5 to 6 
Fireface UC ADAT 7 to 8  Fireface UC ADAT 7 to 8  Fireface UC ADAT 7 to 8 










