Ross 9516DR-004-03, User Manual, Page: 21 / 26

DAC-9516 User Guide (v3.0) Setup • 21
Audio Levels
Figure 6.3 and Figure 6.4 illustrates that amplitude vs. distortion for analog and digital audio equipment show that
digital audio does not gradually degrade (become more distorted) as the amplitude increases.
Likewise, the digital audio signal does not exist above 0dBFS. For these reasons, the interface between existing
analog house reference standards and digital audio standards are as shown in
Table 6.4 .
The coarse input level headroom adjustment is made with the 'A Level' and 'B Level' switches. These switches put
the available headroom of the D/A Converter in the +18dBFS or +24dBFS range.
The fine input level, headroom adjustment is made using the 'A Gain' (RV1) and 'B Gain' (RV2) potentiometers.
These pots provide ±6dB adjustment on the +18dBFS and +24dBFS switch settings. Using these adjustments, the
total headroom is adjustable over the -12dBFS to -30dBFS range.
This means that for a -20dBFS input, the analog outputs may be set to -8dBu to +10dBu. Likewise, for a -18dBFS
input, the output may be set anywhere in the range of -6dBu to +12dBu. Keep in mind that the maximum output
level (1% THD+N) is 27dBu (@ 1kHz).
Figure 6.3 Analog Audio Figure 6.4 Digital Audio
Table 6.4 Analog House Reference and Digital Audio Interface
Reference Headroom Max. Input Application
0dBu 14dB +14dBu AES/EBU for Audio Production
+4dBu 20dB +24dBu AES/EBU for Audio Production
+8dBu 18dB +26dBu AES/EBU for 525 Video
+4dBu 18dB +22dBu AES/EBU for 625 Video
+4dBu 22dB +26dBu AES/EBU for 625 Video
A
M
P
L
I
T
U
D
E
Saturation
Operating Level
+4dBu or +8dBu
DISTORTION
A
M
P
L
I
T
U
D
E
Saturation
0dBFS
Operating Level
-20dBu or -24dBu
DISTORTION
Headroom