Analog Connections; Line Inputs - RME Audio Hammerfall HDSPe AIO User Manual

22. Analog Connections

22.1 Line Inputs

The HDSPe AIO has an unbalanced stereo Line input via RCA connectors. The optional analog
XLR breakout cable turns the inputs into fully balanced ones.
The electronic input stage is built in a servo balanced design which handles unbalanced and
balanced signals correctly, automatically adjusting the level reference.
When using unbalanced cables with the XLR breakout cable: be sure to connect the 'ring'
contact of a stereo TRS jack, and pin 3 of a XLR jack, to ground. Otherwise noise may oc-
cur, 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 HDSPe AIO internally uses hi-quality elec-
tronic switches, which allow for a perfect adaptation of all inputs to the three most often used
studio levels.
The 'standardized' studio levels do not result in a (often desired) full scale level, but take some
additional digital headroom into consideration. The amount of headroom is different in different
standards, and again differently implemented by different manufacturers. Because of this we
decided to define the levels of the HDSPE AIO in the most compatible way.
Reference
Lo Gain
+4 dBu
-10 dBV
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.
42
0 dBFS @
+19 dBu
+13 dBu
+2 dBV
User's Guide HDSPe AIO © RME
Headroom
15 dB
9 dB
12 dB