page 1 – 7
VP-8IP / Sep 2013
G E N E R A L I N F O R M A T I O N
Digital STL:
If using a Digital STL that employs audio compression, then it is highly recom-
mended that the VP-8
iP
be placed at the transmitter site. This is primarily because the
encoding schemes used in such STL’s will not accurately pass the well-defined peak
levels created by the VP-8
iP
.
The VP-8
iP
can be placed at the studio end of a compressed STL with at least two
caveats:
- You will not be able to use the composite clipper in the VP-8
iP
when it is operating
in FM mode. While most digital exciters offer a composite clipper function, they
are typically quite crude in their operation by comparison to what is inside the
VP-8
iP
and are never the optimum choice when sound quality is important.
- Compressed (data reduced) STL’s do not perform well when competitively pro-
cessed audio is presented to their inputs. This is primarily because when dense
audio is presented to these codecs they have fewer “opportunities” to remove
redundant audio information and mask that removal. Therefore, codec operation
may be much more obvious – potentially more so than what might occur with
the processing located after the codec where the masked artifacts are simply
unmasked by the increased “gain” due to processing.
Energizing
Assuming the VP-8
iP
Digital Audio Processor is correctly rackmounted, you may
now energize it. There is no power switch. The AC line input voltage is permitted to
be between 90 and 260 VAC, 50 or 60Hz. Power consumption is under 100VA.
Aggressive AC input filtering is utilized at the AC input of the VP-8
iP
; however it
is always advisable to use external surge protection and/or an uninterruptible power
supply (UPS), especially where AC power quality is questionable, such as at a remote
transmitter site.
Power conditioning, surge suppression, and even power backup devices are wise
investments when using sensitive modern electronic devices that use an internal
computer.
Use of a UPS (uninterruptible power supply) is a good idea and will protect the
VP-8
iP
from short duration power interruptions which may cause it to reboot. During
boot up, audio is interrupted for approximately 20 seconds.
