10
Back-up Supply
The back-up supply is on a 2-pin 7.62 mm pitch screw-
terminal connector [31]. A mating connector is supplied
with the unit. The input voltage range is 12 to 48 VDC.
LEDs [6] and [30] indicate the status, refer to section Status
LEDs on page 17.
The back-up supply is a floating design, the -
input is not connected directly to chassis ground.
The absolute voltage on - as well as + input must be kept
within 65 V from chassis ground voltage. The PPTC
resettable internal fuse is not user serviceable.
Analogue Audio Connections
All analogue audio connections are on 3-pin 3.81 mm-
pitch screw-terminal connectors. Mating connectors are
supplied with the unit. All audio connections (both inputs
and outputs) should be wired according to the diagram
below:
Screen
Hot (+):
Red (UK) or
Blue (US)
Cold (–):
Black (UK) or
White (US)
fig.6: Analogue Audio Connectors
To minimise hum and noise pickup, balanced
interconnections between audio sources and the Octadrive
DSP-DN should always be used wherever possible. If
driving from an unbalanced source, use the same wiring
as shown above at the Octadrive DSP-DN end, but connect
the ‘hot’ core to the signal output and the ‘cold’ core to
the ground terminal of that output; the cable’s own screen
should be connected at the Octadrive DSP-DN end only.
Unbalanced connection to the Octadrive DSP-
DN’s outputs defeats the unit’s primary purpose
and should never be used.
Analogue Inputs
The two transformer-balanced Analogue inputs are
on the connectors [20] and [21]. As with other AXYS®
products (e.g., Intellivox loudspeakers and Industry Amps),
the normal routing of the input signals may be altered by
enabling auto-input switching from WinControl.
In normal operation, both inputs route internally to all
eight outputs. If auto-input switching is enabled, only
Input 1 is used. If auto-input switching is then triggered
- either by pilot-tone failure or low signal level - Input
2 is used instead. Note that input channel priorities are
assignable in WinControl, and Input 2 may be used as
the “normal” input instead if wished. See “Auto-input
switching” on page 15 for more information on use of
auto-input switching, and also the WinControl Help files.
The inputs can accept levels up to +21 dBV peak.
Analogue Outputs
The transformer-balanced, low impedance Analogue
outputs are on connectors [22] to [29]. The output stages
are capable of driving long cable runs with minimal signal
degradation. However, it should be noted that with very
long runs (e.g., >500 m), the cable properties become
significant and high frequencies may be attenuated. This
may be an issue if the system uses an HF pilot-tone for
fault reporting, and the cable used should be a type with
low series resistance and capacitance.
The outputs may be globally set to “high-gain” or “low-
gain” mode from the unit’s Volume tab in WinControl.
Analog output gain has options of 0 dB (low-
gain, the default value) or 14 dB (high-gain). The “high-
gain” setting should be selected if the Octadrive DSP-DN
is being used to drive very long lines where signal loss and
potential interference is anticipated.
