Grass Valley Apex v.2.0 - Manual (Page 95)

APEX — Installation and Service Manual 97
CX-34000 Control Crosspoint Board Configuration
V-fade (Silent Switching)
The Apex utilizes a silent-switching design to minimize unwanted clicks
and pops. You can turn this feature on or off for each output board (i.e., in
blocks of 32 outputs) in the Standard Apex systems.
Note Output boards must be using a Video (not AES) reference to perform V-fades.
The V-fade starts 20 msec before the start of the frame boundary at which
the switch is going to occur. The volume fades down linearly to 0 at the
frame boundary, at which instant the switch occurs (early in line 9), then the
audio volume is faded back up to full volume linearly over the next 20
msec. Since each output card has its own set of V-fade setting DIP switches,
one can enable V-fade on each output card independently. However, all 32
streams on each output card get the same setting.
In Auto mode, V-fade does not occur if the audio stream is compressed
(e.g., Dolby E). This is the reason why the use of V-fade in the
Always On
mode (S28-7 OFF and S28-8 ON ) is not recommended.