Auditronics ALM-12d, Technical Manual, Page: 16 / 101

I N S T A L L A T I O N a n d P O W E R
page 1 – 8
ALM-12d / Oct 2001
Connection Procedures
As supplied from the factory, the console requires no logic connections
to function. Therefore an orderly installation begins with the audio wiring.
Proceed through the manual, chapter by chapter, until all slots have been
wired to suit your particular installation requirements. Once proper audio
operation is verified, go back to Chapter 3 and proceed with control wiring.
Digital Audio Connections
CABLE - All AES/EBU input and output digital audio connections are
balanced and should be made using a high quality digital audio cable. Be
sure to select a digital audio cable with an integral drain wire of the same
wire gauge (AWG) as the twisted pair. Typical AES/EBU digital audio
cable has a very low characteristic capacitance per ft (pF/ft), and a nominal
impedance of 110
Ω
. High quality digital audio cable offers better signal
transmission performance versus typical analog audio cable, especially
over long cable runs. Check the cable manufactures data sheet to be sure
the cable you plan to use will work in your application.
CONNECTORS - All AES/EBU connections are made with the
supplied DB-25 connectors. These crimp style connectors will accept wire
gauge 24 - 28AWG.
SPDIF INPUTS - The SPDIF (Sony/Philips Digital Interface) or
“consumer” digital audio interface is a two wire unbalanced signal
typically on a single RCA style connector. To connect SPDIF devices to
the ALM-12d console simply wire the SPDIF center conductor (HOT) to
the digital input HI pin and SPDIF shell (ground) to the LO pin. Connect
the digital input SH at the console end only.
Unbalanced Connections (analog audio)
ANALOG INPUTS — Wire to the console with typical shielded two
conductor cable (like Belden 9451), just as if you were connecting a
balanced source. At the unbalanced source machine’s output, connect the
black wire (LO) to the shield.
ANALOG OUTPUTS — ALM-12d consoles use a balanced output
circuit which behaves exactly like the secondary of a high-quality trans-
former, with no center tap—this output is both balanced and floating.
Either the HI or LO side of the output should be strapped to ground, with
the output taken from the other side. (Normally you’d strap LO to ground,
and take HIGH to feed your unbalanced equipment.)
ALM-12d / Oct 2002