User`s guide

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User's Guide Fireface UFX © RME
19. Analog Inputs
19.1 Line Rear
The Fireface has eight balanced Line inputs as 1/4" TRS jacks on the back of the unit. The elec-
tronic input stage is built in a servo balanced design which handles unbalanced (mono jacks)
and balanced (stereo jacks) correctly, automatically adjusting the level reference.
When using unbalanced cables with TRS jacks: be sure to connect the 'ring' contact of the
TRS jack to ground. Otherwise noise may occur, caused by the unconnected negative input
of the balanced input.
One of the main issues when working with an AD-converter is to maintain the full dynamic
range within the best operating level. Therefore the Fireface UFX internally uses hi-quality elec-
tronic switches, which allow for a perfect adaptation of all rear inputs individually to the three
most often used studio levels.
The Fireface UFX uses the following level references:
Reference 0 dBFS @ Headroom
Lo Gain +19 dBu 15 dB
+4 dBu +13 dBu 9 dB
-10 dBV +2 dBV 12 dB
The above levels are also found in all other RME devices. Therefore they are fully compatible to
each other.
19.2 Microphone / Line / Inst Front
The four balanced microphone inputs of the Fireface UFX offer a digitally controlled gain of 0 to
65 dB via XLR/TRS combo jacks. The gain range is 65 dB, adjustable in 1 dB-steps over a ran-
ge of 55 dB. The soft switching, hi-current Phantom power (48 Volt), switchable per channel,
provides a professional handling of condensor mics. Up to a level of +12 dBu, the front XLR
input can also be used as Line input.
The unbalanced TRS Line inputs, which can be used alternatively, add even greater flexibility to
the Fireface UFX. With 800 kOhm input impedance (Hi-Z), TRS jack and adjustable input gain
over a range of 55 dB the front-side inputs can be used perfectly with keyboards, sampler, CD
player, guitars and much more. These inputs handle levels from –34 dBu up to +21 dBu, turning
them into full level Line inputs. Thus the unit can also be used as Line gain amplifier.
The TRS jacks are free of phantom power.
A two colour LED display a present signal (green, from –46 dBFS) and warns against overload
(0 dBFS).
Channels 9 to 12 feature an automatic overload protection. AutoSet tries to keep a headroom
of 6 dB. Levels higher than -6 dBFS will permanently reduce the gain. To check set the chan-
nels to a high gain and apply an input signal. The button will quickly rotate back to a gain that is
appropriate. While AutoSet in the UFX is not exactly the same as in the RME Micstasy (with
extreme overloads distortion will occur for the fraction of a second before the level is set cor-
rectly), it works quite well in real-world applications and will prevent distorted recordings reliably.
Using stereo channels AutoSet operates ganged. AutoSet can be activated in TM FX or directly
at the unit in the channel settings. A push on Encoder 1/2 toggles AS on/off.
As soon as AutoSet reduces the gain the label AS, shown in the front display, changes its color
from black to dark blue.