User guide

Workstation Card Rev 1.2 Operation
Genex Research Limited Page 5
Operation
Starting Up
The GXA8 and GXD8 function as standalone converters facilitating A/D and D/A operations using
AES/EBU or any other optional interface cards (e.g., ADAT, TDIF, SDIF-2 or DSD) even when the
GX8-WSIF card is installed. However, when the computer starts up or Pro Tools is run, the GX8-
WSIF card receives a message from the computer, which activates the card. The whole converter is
now under the control of the audio software! Unfortunately, no message is sent when the software is
shutdown so the converter is not released from the card. In order to use the converter in its normal
standalone mode, switch it off and then on again.
NOTE: The level meters on the GXA8 always show the input (i.e. actual recording) level and the
GXD8 meters always show the output level. The meters on interfaces such as the Digidesign 888/24
I/O always show the system output level. The input metering of the GXA8, with it peak over and hold
modes, is an important feature to note as it will instantly highlight any digital clipping at the input.
Connecting the Computer, GXA8 and GXD8
The workstation card may be fitted to either the GXA8 or the GXD8. If you approach the setup in the
following way, it should be easier to understand how the converters connect to Pro Tools (or other
DAW applications capable of using the Digidesign hardware interface).
Both the GXA8 and the GXD8, when fitted with a workstation card, can be considered as input / out-
put boxes.
• The GXA8 is an analogue in, digital out i/o box
• The GXD8 is a digital in, analogue out i/o box
This makes setting up a larger system more flexible. For example, with a system requiring eight ana-
logue inputs and twenty-four analogue outputs, expense does not have to be wasted on unused ana-
logue inputs. This configuration can be achieved with three Workstation cards, one GXA8 and three
GXD8s. The first workstation card is fitted to the GXA8 and a GXD8 is connected to the GXA8 (as
illustrated below). This provides the eight analogue inputs and the first eight analogue outputs. The
second and third Workstation cards are fitted to the second and third GXD8 to provide analogue out-
puts nine to twenty-four. Of course, these two GXD8s also provide sixteen digital inputs into the sys-
tem!
Workstation Card fitted to the GXA8
If the workstation card is in the GXA8, the digital outputs of the GXA8 are typically connected
to the digital inputs of a GXA8 (this can be via the AES connectors standard to both units or
the AES expansion, ADAT, TDIF or SDIF-2 cards). The GXD8 should be clock-slaved to the
GXA8 (via word clock, AES, etc). This is illustrated below:
Connection Diagram – GXA8 fitted with Workstation card
GXA8 with Workstation Card
8 analogue inputs
Digidesign Peripheral cable
GXD8
Four AES cables or
ADAT optical or
TDIF etc
8 analogue outputs
Optional word clock
Digital i/o via second op-
tional expansion card