DCS dCS 904 User Manual

Page of 86
dCS 904 User Manual
 Manual for Software Version 1.5x and 1.36
dCS Ltd 
June 2000
Manual part no: DOC135904 iss 2B2
Page 21
135904ma2b2.pdf file available from website
Contact 
dCS
 on + 44 1799 531 999 
email to: more@dcsltd.co.uk
(inside the UK replace + 44 with 0)
web site: www.dcsltd.co.uk
On
XLRs carry either DSD 4 format or P3D format, as
set by he DSD menu item.  In P3D format, where
DSD to be packed into 3 AES3 links, the 4
th
 XLR
output carries a PCM encoded signal for metering
purposes, to allow DSD to be recorded on existing
8 track 24 bit PCM recording machines, at a lower
than normal level
This XLR control function is separate from DSD mode for safety reasons.
Because DSD into a PCM device can cause full scale noise, with a very high
high frequency content that can damage speakers, this feature has to be
explicitly turned on.
If it is turned on, and DSD mode is turned on, the unit outputs DSD packed into
AES3 data streams in the appropriate manner.  Contact dCS for further details
If DSD is packed into AES3 links (DSD 4 or P3D), the dCS 904 sets the Non
Audio flag in the AES3 message, so that a DAC further downstream will mute if
it cannot accept the format, but beware:
IMPORTANT! 
if the Non Audio flag is stripped  by the recorder, a DAC could accept DSD
data as AES3 PCM and will output potentially damaging full scale noise.
DSD O
-
This page selects the output format of the SDIF connectors – SDIF-2 or SDIF-3.
SDIF-3 is only valid for DSD:
SDIF2
The BNCs output SDIF-2 formatted DSD in ADC
mode
On
The BNCs output SDIF-3 (embedded clock) in
ADC mode.
Definitions of these formats are available from the SONY Corporation.
Tone
-
This accesses a test generator, whose level and frequency can be adjusted.
Pressing Set enters a submenu, which accesses the following functions:
Level
The output level, in dB0. It can be changed in
0.1dB steps using the 
Up
 and 
Down
 buttons.
Freq
The output frequency, in kHz. It can be changed
below 1 kHz in 10 Hz steps, or above 1 kHz in
100 Hz steps by using the 
Up
 and 
Down
 buttons.
On/Off
Toggles whether the generator is on or off.
Up
Allows the menu to be re-entered to set other
functions. Alternatively, if left, the menu will just
time out keeping the last settings.
At power up, the generator is set to 
Off
1 kHz 
and 
–18dB0
 as a safety measure.
When in use, if the generator is turned Off, the unit remembers the last
frequency and level setting.
The generator frequency can be set to much finer (32 bit) resolution using the
RS-232 control.  See section 
for more details.