Studio Technologies 60A - Manual (Page 13)

Model 60A/61 User Guide Issue 1, June 2003
Studio Technologies, Inc. Page 13
The best way to understand how to use
the auxiliary switcher sections is to de-
scribe several possible applications. One
excellent application would be to allow
the Model 60A to support up to three sets
of control room monitor loudspeakers. The
auxiliary switcher would be used to select,
at line level, which amplifier(s) or amplified
speaker(s) are receiving the Model 60A’s
control room signal. This is almost trivial
to accomplish. Start by preparing two
¼-inch 3-conductor patch cables, each
containing about 24 inches of cable. Plug
one end of each cable into the control
room output jacks. The other ends will
plug into the auxiliary switcher’s in/out
jacks. Ensure that left out is plugged into
left in/out; right out to right in/out. Now
connect the inputs of the amplifiers, or
amplified speakers, to the auxiliary
switcher’s jacks labeled A, B, and C.
Another possible application would be to
use the auxiliary switcher as a 3-input/
1-output source selector. In this case the
sources would be connected to the jacks
labeled A, B, and C. The output would be
connected to the auxiliary switcher’s in/out
jacks. That’s all there is! This implementa-
tion could be used to support external
equipment having nothing to do with other
Model 60A functions. Or, it could be used
to increase the number of line level inputs
connected to the Model 60A from four to
six. This may be useful if extra sources
are required for use by the control room,
headphone, and dub out functions. In this
case the auxiliary switcher would serve
as a pre-selector for one of the four line
inputs. The in/out jacks would be con-
nected to the selected line input, most
likely input 4. The additional sources would
then be connected to the jacks labeled A,
B, and C. Obviously this implementation
is not without compromises. For example,
all input sources connected to the auxiliary
switcher section must have the same
nominal level. Also, only one of the
sources connected to the auxiliary
switcher should be selected at any time.
But in certain cases the trade-offs will be
well worth having the additional inputs.
Life is all about compromises!
A few technical details about the auxiliary
switcher section may be helpful. As previ-
ously discussed, the eight jacks and
associated switches are designed to
handle stereo, balanced audio signals.
Both the audio + and audio – signals for
both the left and right channels are inde-
pendently switched. Being passive, there
is no specified nominal signal level. As
with all the other jacks associated with
the Model 60A, standard ¼-inch plugs
are used to interface with the auxiliary
switcher. Connections should be made
so that tip connects to audio high (+ or
hot), ring to audio low (– or cold), and
sleeve to shield. It’s important to note
that the sleeve connections on all eight
jacks connect to the chassis ground of
the Model 60A. This is consistent with
all the other jacks on the Model 60A.
To minimize the chance of noise pickup,
the auxiliary switcher contains internal
termination resistors. In most cases the
factory-selected implementation will be
perfectly acceptable. However, in special
cases a change may be warranted. Please
refer to the Technical Notes section of this
guide for additional information.
Connecting the Model 60A to the
Model 61
A standard 5-conductor MIDI-style cable
is used to connect the Model 60A to the
Model 61; a cable is included with each