APA-4E8 Operator’s Manual
Page 21
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Input Sources
APA is exceptionally flexible as regards input routing and mixing, and can receive audio from
a variety of sources: analogue audio, stereo AES audio, multichannel networked audio, along
with internal noise and sine wave generators and audio file playback from the internal SD
card (for emergency evacuation messages only).
With the exception of the internal oscillators, all the other audio sources are available on the
input side of the 12 x 12
switched
routing matrix.
The four DSP “Input” processing channels, can receive signals from any of the available
signal sources but please note the following:
-
As AES inputs share physical XLR connection with two analogue inputs, you cannot
source analogue input A and AES A at the same time. This is also true for analogue
source C and AES C.
-
AES C+D shares an input to the switching matrix with mono “wav” file playback for
emergency evacuation messaging. This is enabled by either a contact closure on the
local amplifier, or by a network message. Please see the section on page 47 for more
information.
AES Inputs
APA can accept a pair of AES3 digital audio streams in stereo channel pairs. As explained in
the section above, these share the physical connectors for analogue inputs A and C for the
two digital inputs. They can be selected on a channel pair basis so one pair of digital and one
pair of analogue inputs can be in use together if required.
The AES inputs accept sample rates from 32kHz up to 192kHz, at 24 bit resolution. In AES
input mode, rear panel indicators for inputs A and C will show digital input status and sample
rate.
Flashing red — AES input active, no signal lock (so no audio!)
Steady red — locked to 48k AES stream
Steady yellow — locked to 96k AES stream (ideal)
Steady green — locked to 192k AES stream
Via the Quick Inputs Monitor on the front panel, the AES input levels can be verified by
selecting Quick Inputs Monitor using BACK and NEXT from the home screen and then turning
the encoder to select AES Inputs:
