RME Audio Fireface 400, User Manual, Page: 56 / 100

56
User's Guide Fireface 400
© RME
28. Analog Outputs
28.1 Line
The eight short circuit protected, low impedance line outputs are available as 1/4" TRS jacks on
the back of the unit. The electronic output stage is built in a servo balanced design which han-
dles unbalanced (mono jacks) and balanced (stereo jacks) correctly.
To maintain an optimum level for devices connected to the analog outputs, the Fireface 400
internally uses hi-quality electronic switches, which allow for a perfect adaptation of all outputs
to the three most often used studio levels.
As with the analog inputs, the analog output levels are defined to maintain a problem-free op-
eration with most other devices. The headroom of the Fireface 400 lies between 9 and 15 dB,
according to the chosen reference level:
Reference 0 dBFS @ Headroom
Hi Gain +19 dBu 15 dB
+4 dBu +13 dBu 9 dB
-10 dBV +2 dBV 12 dB
With +4 dBu selected, the according headroom meets the latest EBU recommendations for
Broadcast usage. At -10 dBV a headroom of 12 dB is common practice, each mixing desk op-
erating at -10 dBV is able to send and receive much higher levels. Lo Gain is best suited for
professional users who prefer to work balanced and at highest levels. Lo Gain provides 15 dB
headroom at +4 dBu nominal level.
The above levels are also found in our ADI-8 series of AD/DA converters, the Multiface, and
even in our Mic-Preamps QuadMic and OctaMic. Therefore all RME devices are fully compati-
ble to each other.
28.2 Phones (7/8)
Channels 7/8 of the Fireface are available on the front via one 1/4" unbalanced TRS jack (ste-
reo output). These channels use the same converters as the other line outputs, therefore offer
the same technical data (112 dBA SNR).
These outputs are special low impedance types, ready to be used with headphones. But they
can also be used as high-quality (yet unbalanced) line outputs. To optimize this stereo output
for monitoring purposes, outputs 7/8 have their own 3-stage hardware-based reference level
circuitry, providing perfect pre-adjustment for the connected monitor speakers. The main vol-
ume control is then performed via TotalMix, either at the computer or directly at the unit (rotary
encoder, PH).
In case the output should operate as
line output, an adapter TRS plug to
RCA phono plugs, or TRS plug to TS
plugs is required.
The pin assignment follows interna-
tional standards. The left channel is
connected to the tip, the right channel
to the ring of the TRS jack/plug.