User`s guide

User's Guide Fireface 400 © RME
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11.2 Settings dialog – Input Gain
Mic
Channel 1/2 of the Fireface 400 have digitally controlled microphone preamps of the highest
quality. The digital control offers a gain setting in steps of 1 dB within a range of 10 dB to 65 dB.
The configuration is done either directly at the unit via the rotary encoder, or via the Settings
dialog's tab Input Gain. The option Link simplifies the setup in case both channels shall have
the same setting/values. The current gain is displayed in dB below the fader.
In the lower range the fader jumps from 10
dB to 0 dB. This useful additional setting
allows to operate even line signals with the
microphone input (up to +10 dBu).
Instrument
The inputs 3 and 4 can not only be config-
ured on the Settings dialog's main page, but
also have a digitally controlled preamp. It
allows for an additional gain between 0 and
18 dB, in steps of 0.5 dB. The configuration
is done either directly at the unit via the ro-
tary encoder, or via the Settings dialog's tab
Input Gain.
The option Link simplifies the setup in case
both channels shall have the same set-
ting/values. The current gain is displayed in
dB below the fader. Further information is
found in chapter 27.3.
11.3 Settings dialog - DDS
Usually soundcards and audio interfaces generate their internal clock (master mode) by a
quartz. Therefore the internal clock can be set to 44.1 kHz or 48 kHz, but not to a value in be-
tween. SteadyClock, RME's sensational Low Jitter Clock System, is based on a Direct Digital
Synthesizer (DDS). This superior circuitry can generate nearly any frequency with highest pre-
cision.
DDS has been implemented into the Fireface with regard to the needs of professional video
applications, as well as to maximum flexibility. The dialog DDS includes both a list of typical
video frequencies (so called pull up/pull down at 0.1% and 4%) and two faders, which allow to
freely change the basic sample rate in steps of 1 Hz (!).
The DDS dialog requires the Fireface to be in clock mode Master! The frequency setting will
only be applied to this one specific Fireface!
Changing the sample rate in bigger steps during record/playback often results in a loss of
audio, or brings up warning messages of the audio software. Therefore the desired sample
rate should be set at least coarsely before starting the software.