Print Date 04/01/11 Page 14 of 42 E2165-00MA-04
1.3.2: Stereo Encoder Module Specifications (/S option only)
Mono/AES Input
Standard AES/EBU serial, digital, stereo audio Input via 3 pole XLR connector.
Sensitivity : adjustable from rear panel.
Input impedance : 110
Ω
floating/balanced, transformer isolated
Note that a valid AES/EBU signal at this input will take precedence over the
left/right analogue inputs to the Stereo Encoder module. In this case, the
specified overall performance and the pre-emphasis etc. selected will also
apply to the digital signal (see below).
Left/Right Inputs
DC to 15kHz left/right analogue stereo inputs via two 3 pole XLR connectors
(Note that a valid AES/EBU signal at the Mono/AES input will take precedence
over these analogue inputs).
Input impedance internally preset to balanced 600
Ω
or 20k
Ω
(600
Ω
or 13.3k
Ω
if externally unbalanced by grounding one balanced input side).
Input sensitivity for
±
67.5kHz deviation (excluding pilot) at 400Hz :-
+8dBm (600
Ω
input) : +8dBu : 5.5V peak to peak
(left and right separately adjustable from rear panel with maximum sensitivities
typically -4dBu/1.4V).
Pre-emphasis set from front panel or remotely to :- none, 25uS, 50uS or 75uS.
Overall frequency response : better than
±
0.4dB over 30Hz - 15kHz (rel. 1kHz)
(integral lowpass filters provide greater than 60dB rejection at 19kHz).
Measured with deviation (excluding pilot) set to 18dB below
±
67.5kHz
(
±
8.4kHz) at 400Hz modulation - fixed test level to pre-emphasised input then
causing deviation to rise with modulation frequency.
Overall stereo separation : - better than 48dB over 40Hz to 10kHz (typ. 60dB)
Overall harmonic distortion : better than –58dB (0.13%) over 40Hz to 10kHz
(typ. –64dB). Measured in a bandwidth of twice the fundamental to 22kHz.
Overall signal to noise ratios : -
Overall signal to noise ratios better than : - RMS A weighted : 70dB
RMS CCIR468-3 weighted : 58dB - RMS unweighted : 65dB
Q-Peak CCIR468-3 weighted : 58dB - Q-Peak CCIR unweighted : 58dB
All measured relative to deviation of
±
67.5kHz (excluding pilot) and 400Hz
modulation (set up with an RMS unweighted measurement).
Pilot Tone Output
and Deviation
19kHz
±
2Hz output via 50
Ω
SMA connector
Pilot deviation :
±
6.75kHz
(adjustable from the rear panel over at least
±
6kHz to
±
7.5kHz)
Output Impedance : approximately 100
Ω
.
Output level : approximately 5V peak to peak sinewave (open-circuit)
38kHz Sub-carrier
Suppression
Better than 40dB relative to
±
75kHz deviation (typically better than 60dB).
Limiter and
Clipper
Separately selectable from front panel or remotely.
Automatic level control circuit limiting maximum peak deviation to
approximately
±
55kHz. Soft clipping circuit operating at approximately
±
70kHz.
