Studio Technologies 68 V.1 - Manual (Page 12)

Issue 2, June 1999 Model 68/69 User Guide
Page 12 Studio Technologies, Inc.
for Surround
commercially made cable assemblies. Let
the large market for DA-88-style cabling
help you painlessly install your system!
When it came time for Studio Technolo-
gies to test the first Model 68 Central
Controller, standard DA-88 harnesses
were purchased. They turned out to be
of very good quality, and the cost was very
reasonable. Needing to change the sex of
the last two connectors on the output
harness (to support the L/R Bypass input)
was a trivial matter.
Surround and Stereo Audio Inputs
The connectors labeled INPUT 1 (SUR-
ROUND A) & INPUT 3 (STEREO A) and
INPUT 2 (SURROUND B) & INPUT 4
(STEREO B) are used to interface with
the 16 line input circuits. Each input circuit
is electronically balanced, and is intended
for connection to balanced or unbalanced
sources with a nominal signal level of
+4dBu. A trim potentiometer is associated
with each input, allowing the input sensitiv-
ity to be adjusted over a ±2dB range. 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 + on the D-sub,
signal low to – on the D-sub, and shield to
the D-sub’s shield connection. With an
unbalanced source, connect signal high to
the + connection on the D-sub, and shield
to both the – and the shield connection on
the D-sub. If connecting to an unbalanced
source in this manner results in hum or
noise, try connecting signal high to + on
the D-sub, and shield to – on the D-sub;
leave the shield connection on the D-sub
unterminated.
It is highly recommended that at least one
of the surround inputs be wired by way of
an audio patch bay. This will allow the
Signal Signal
Connections High (+) Low (–) Shield
SURROUND B-L 24 12 25
SURROUND B-C 10 23 11
SURROUND B-R 21 9 22
SURROUND B-LS 7 20 8
SURROUND B-RS 18 6 19
SURROUND B-SUB 4 17 5
STEREO B-L 15 3 16
STEREO B-R 1 14 2
Notes: 1) Connector type on Model 68 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 5. Connections for Inputs Surround B
and Stereo B
Signal Signal
Connections High (+) Low (–) Shield
SURROUND A-L 24 12 25
SURROUND A-C 10 23 11
SURROUND A-R 21 9 22
SURROUND A-LS 7 20 8
SURROUND A-RS 18 6 19
SURROUND A-SUB 4 17 5
STEREO A-L 15 3 16
STEREO A-R 1 14 2
Notes: 1) Connector type on Model 68 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 Stereo A