Crystal Vision
Statesman operation in mode 3
TANDEM-200 User Manual R1.7
53
13/02/2008
Audio Monitoring
A powerful stereo monitoring bus provides audio monitoring at the card-edge headphone
socket and rear connector.
TANDEM-200 audio monitoring (mode 3)
A fully selectable analogue monitoring output is fed to a miniature stereo jack socket at
the card edge. Select any valid stereo signal to be monitored with the monitoring drop-
down list.
The RM04 and frame rear connector can also receive the same user-selectable analogue
monitoring signal as the headphone socket or an automatically assigned AES monitor
output. The AES output can be routed via external devices to further process TANDEM
audio which may then be re-entered into digital audio input cards in another TANDEM
card.
In mode 3 the AES monitor bus will monitor de-embedder outputs when de-embedders
are ON. Digital silence will be output when de-embedders are off.
See section 10.3 for further discussion of audio monitoring and pinout details.
SDI Crystal control
There is a single PLL module that may be inserted into either SDI 1 only, SDI 2 only, or
left out of circuit (OFF).
The SDI signal accumulates an ever-increasing amount of jitter as it progresses through
an SDI installation, and as it passes through most equipment in its path. To minimize this
effect, TANDEM has an SDI crystal controlled re-clocker. This is a form of 'Time Base
Corrector' which sets the output SDI signal to the same mean frequency as the input, but
re-clocked by a crystal controlled Phase Locked Loop [PLL], to produce extremely low
jitter in the SDI output.
The PLL is situated in the input SDI path prior to processing, so all of the functions of
that side, as well as the SDI output, benefit. The SDI PLL should be locked to the SDI
path that best suits the application.
