Surround inputs – Studio Technologies 78 2004 User Manual

Page 10

Issue 5, January 2004

Model 78/79 User Guide

Page 10

Studio Technologies, Inc.

for Surround

prepared for the monitor outputs is identi-
cal to that of a DA-88-style output harness.
Please refer to Figures 4 and 5 for the
exact connection details. Note that unlike
a DA-88-style harness, the Model 78’s
D-sub connectors use 4-40 threads. This
complies with the original design standard
for D-subminiature connectors.

Unless there’s a special need, it may be
cost and time effective for you to purchase
commercially made cable harnesses. Let
the large market for DA-88-style cabling
help you painlessly install your system!

Surround Inputs

The connectors labeled Input Surround A
and Input Surround B are used to interface
with the 16 input circuits. Please refer to
Figure 4 for details on the exact “pin out”
of the D-sub connectors. Each input cir-
cuit is electronically balanced. They are
intended for connection to balanced or
unbalanced sources with nominal signal
levels of –12 dBV to +6 dBu. A 15-turn
trim potentiometer is associated with each
input, allowing the input sensitivity to be
adjusted to match the source’s level. The
conﬁguration section of this guide provides
details on using the trim pots.

Balanced sources should be wired so that
signal high is connected to +, signal low to
–, and shield to the shield connection. With
an unbalanced source, connect signal high
to the + connection, and shield to both the
– and the shield connections. If connecting
to an unbalanced source in this manner re-
sults in hum or noise, try connecting signal
high to +, and shield to –; leave the shield
connection unterminated.

It is highly recommended that at least one
of the surround inputs be wired by way

Signal

Connections

High (+)

Low (–)

Shield

LFE

Notes: 1) Connector type on Model 78 is 25-pin D-subminiature

female. Installer must provide plug (male). Connector

uses 4-40 threaded inserts for locking with mating plug.

2) Wiring scheme follows TASCAM DA-88 convention.

Standard DA-88-type wiring harnesses are directly

compatible, with the exception of 4-40 screw threads

being required.

Figure 4. Connections for Inputs Surround A
and Surround B