Studio Technologies 591 - Manual (Page 11)

Issue 1, September 1999 Model 58/591 User Guide
Page 14 Studio Technologies, Inc.
Warning: It is very important that
signals connected to the bypass input
be “post” a level control, i.e., attenu-
ated from line level. Connecting a
standard line level audio signal can
result in damage to monitor loud-
speaker systems or, more critically,
to the ears of listeners.
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 the connection method
depends on the requirements of the moni-
tor speaker system’s input. This is be-
cause routing of the bypass input to the
monitor outputs does not involve any
active circuitry. Whenever the bypass
feature is active, the signal connected to
the bypass inputs is simply passed
through to the associated monitor output
channels by means of electromechanical
relay contacts.
Insert Sends and Returns
The connector labeled INSERTS is used
to interface with the two 2-channel insert
sections. Please refer to Figure 6 for
details on the exact “pin out” of the D-sub
connector. The use of the insert sections
will depend on the requirements of the
specific installation. In many cases the
inserts sections won’t be required, and
no connections will need to be made.
The insert sends are electronically bal-
anced, have a nominal level of +4dBu,
and are capable of driving balanced or
unbalanced loads of 600 ohms or greater.
While balanced operation is preferred,
unbalanced operation is not a problem.
To connect to an unbalanced load connect
the + terminal of the D-sub as signal high,
and both the – and shield as the signal low/
shield. For optimal unbalanced operation,
it is important to connect both – and shield
together directly on the D-sub.
Note that the insert sends do not have level
trim potentiometers associated with them.
The output levels are nominally +4dBu,
with channel-to-channel variation of up to
±0.5dB considered normal. It is anticipated
that the equipment connected to the insert
sends will have, if required for correct op-
eration, input level adjustment controls.
The insert returns are electronically bal-
anced, have a nominal input level of +4dBu,
and are compatible with balanced or unbal-
anced sources. Connections should be
made in the same fashion as the main
inputs, described previously.
A trim pot is associated with each insert
return, allowing the input sensitivity to be
adjusted over a ±2dB range. Refer to the
Configuration section of this guide for
details on using the trim pots.
Signal Signal
Connection High (+) Low (–) Shield
SEND 1-1 (L) 24 12 25
RETURN 1-1 (L) 10 23 11
SEND 1-2 (R) 21 9 22
RETURN 1-2 (R) 7 20 8
SEND 2-1 (L) 18 6 19
RETURN 2-1 (L) 4 17 5
SEND 2-2 (R) 15 3 16
RETURN 2-2 (R) 1 14 2
Notes: 1) Connector type on Model 58 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 loosely follows Tascam
DA-88 convention. Modified DA-88-type wiring
harnesses are required, along with 4-40 screw
threads.
Figure 6. Connections for Inserts