Analog Inputs; General - RME Audio ADI-2 Pro User Manual

20. Analog Inputs

The ADI-2 Pro has two analog line inputs that can operate with levels up to +24 dBu. The elec-
tronic input stage uses a servo balanced design which handles unbalanced (TS jacks) and bal-
anced signals (TRS / XLR) correctly, automatically adjusting the level reference.
!
When using unbalanced cables with the XLR inputs, pin 3 of the XLR jack should be con-
nected to ground. Otherwise noise may occur, caused by the unconnected negative input of
the balanced input.
To use the inputs as unbalanced RCA: simply insert a standard TS male to RCA female adap-
ter. Now any RCA / Cinch cable can be easily used with the ADI-2 Pro.
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 ADI-2 Pro internally uses hi-quality elec-
tronic switches, which allow for a perfect adaptation to the four most often used studio levels +4
dBu, +13 dBu, +19 dBu or +24 dBu.
Additionally a digital Trim Gain of 0 to +6 dB, in steps of 0.5 dB, can be applied, to precisely
match the output level of external gear. The 6 dB of digital gain makes the whole range be-
tween +13 dBu and +24 dBu available in steps of 0.5 dB. Due to the larger step of 9 dB be-
tween +4 dBu and +13 dBu, there is a small gap from +4 dBu to +7 dBu.
Trim Gain can also be used to increase the input sensitivity to -2 dBu for 0 dBFS. Note that
digital gain reduces the basic signal to noise ratio of the ADI-2 Pro by the amount of the gain. In
real-world applications this will hardly be any problem, as the worst case SNR of -112 dBu is
very difficult to achieve from most analog sources.
Ref Vrms
+24 dBu 12.28
+19 dBu 6.9
+13 dbu 3.46
+4 dBu 1.23
The analog inputs also feature automatic overload protection. Auto Ref Lev(el) changes to the
next higher reference level when overloads are detected.
21. Analog Outputs

21.1 General

The TS outputs, XLR outputs and the front outputs PH 1/2 are fed from the same DAC, hence
carry the same signal (channels 1/2). They all have individual driver stages with different output
levels, see next chapters for details.
All outputs feature mute components to suppress power on/off noise, even when power fails
instead of switching the unit off via the standby button.
SNR and THD values as well as frequency response are nearly identical on all analog outputs.
Both phones outputs feature mute relay, over-current detection, DC protection, plug detection
and DSP control, like auto assigning volume, volume ramp up, auto balanced mode, dual
phones mode, user interaction at overload detection, and low impedance level meter auto scal-
ing.
42
Digital Gain +6 / 0 dB
+19 dBu to +24 dBu
+13 dBu to +19 dBu
+7 dBu to +13 dBu
- 2 dBu to +4 dBu
User's Guide ADI-2 Pro © RME
Vrms
-
-
+7 = 1.73
- 2 = 0.62