Studio Technologies 591 User Manual

Model 58 Central Controller and

Model 591 Control Console

User Guide

Issue 1, September 1999

This User Guide is applicable for serial numbers:

Model 58 M58-00351 and later

Model 591 M591-00151 and later

© 1999 by Studio Technologies, Inc., all rights reserved

5520 West Touhy Avenue

Skokie, Illinois 60077 U.S.A.

Telephone [phone]

Fax [phone]

www.studio-tech.com

50085-999, Issue 1

Tab le of Contents

Foreword..................................................................... 5

Introduction ................................................................. 7

What This User Guide Covers ................................ 7

StudioComm ........................................................... 7

Model 58 Central Controller .................................... 7

Model 591 Control Console..................................... 7

Applications................................................................. 10

Installation................................................................... 11

Configuration............................................................... 17

Operation .................................................................... 31

Technical Notes .......................................................... 34

Specifications .............................................................. 36

Appendix A.................................................................. 37

MIDI Messages ....................................................... 38

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 3

Forew ord

Simply stated: I had a blast working on these StudioComm components! It is very reward­ing to develop a set of products for a market that’s actually receptive to new ideas and
supportive of innovation.

Mitch Budniak designed much of the hardware and kept us out of “digital trouble.” Carrie
Loving provided engineering support and designed the product graphics. Larry Leviton
wrote the excellent software that makes the hardware “come to life.” Fred Roeck per­formed the mechanical design. Al “PCB PRO” Lux designed the...you guessed it! Joe
Urbanczyk coordinated the safety testing and created the automated test routes for our
Audio Precision System Ones.

Our plans are to continue with other StudioComm components. Your praise, comments, or
complaints are encouraged, helping to keep us going in the right direction. Please contact
me via E-mail at [e-mail].

Sincerely,

Gordon K. Kapes
President

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 5

Introduction

What This User Guide Covers

This User Guide is designed to assist you
when installing and using the Model 58
Central Controller and the Model 591
Control Console.

StudioComm

This StudioComm system starts with a
Model 591 Control Console, a compact
but comfortable “command center,” that is
designed to reside at the operator’s loca­tion. Using a single 9-pin cable, a Model
591 connects to a Model 58 Central Con­troller, which is mounted in a single rack
space.

The Models 58 and 591 were developed
in conjunction with experts in the broad­cast audio field. The overall goal turned
out to be very straightforward: Provide the
necessary technical performance and
features, while keeping it simple to oper­ate! Be certain that users won’t have to go
through a long “learning curve” before they
become efficient. Allow the StudioComm
system to be flexible, but not so much as
to hinder the “big picture.” The end result
achieves these goals, providing extensive
capability in a simple-to-operate format.

Model 58 Central Controller

The Model 58 Central Controller is a
single rack-space unit that supports two
output channels. It provides eight main
inputs, of which four are supported by
the Model 591 Control Console. Two
2-channel insert sections allow connection
to external processing equipment. The
2-channel monitor output section is
switched, using electromechanical relays,

to allow connection to two separate loud­speaker systems. Protection circuitry
provides power-up and power-down pro­tection for the loudspeakers. A 2-channel
meter output provides a “reference” signal,
and is not affected by the monitor output’s
level-control circuitry.

The main inputs, insert sends and returns,
and monitor outputs are electronically
balanced, while the meter outputs are
unbalanced. Fifteen-turn trim potentiom­eters are used to precisely calibrate the
main input, insert return, and monitor
output signals. Audio signal connections
are made using three 25-pin D-subminia­ture connectors. The connectors follow
an industry-standard multi-channel wiring
scheme. A 9-pin D-subminiature connector
is used to connect the Model 58 to the
Model 591 Control Console.

The bypass function allows a line-level
audio source to be passively routed to
the monitor output channels. The bypass
function, along with remote control input 2,
makes it simple for an existing facility to
add monitoring capability, while maintain­ing its existing resources.

An 8-bit micro-controller provides the
logic “horsepower” for the Model 58. DIP
switches are used to select the Model 58’s
unit ID and operating mode. AC mains
power is connected directly to the Model
58, which is factory selected for 100, 120,
220/240V operation. The internal power
supply utilizes a toroidal mains transformer
for quiet audio operation.

Model 591 Control Console

The Model 591 Control Console is a
compact, self-contained unit designed
to be located at the operator’s position.
It allows fingertip control of all monitoring

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Studio Technologies, Inc. Page 7

parameters. Numerous LEDs provide
complete status information. The Model
591 supports four input sources and two
output channels.

The Model 591 provides eight buttons for
selection of the input routing. Two buttons
are associated with each of the four main
inputs, allowing the signals to be routed
to the left and right monitor outputs as
desired. No input has priority over any
other. It is perfectly legitimate to have no
input selected for monitoring, or to have
all inputs routed to both the left and right
monitor outputs. This flexibility is provided
to allow users to monitor how their applica­tion dictates. Note that when inputs are
combined and sent to a monitor output
channel, there is no independent level
control of the individual sources. They
are simply combined (summed).

The input source preset functions allow up
to four pre-configured input routing con­figurations to be selected at the “touch of
a button.” This allows monitoring configu­rations that are often selected to be stored
for ready access.

The monitor output level is controlled
either through the use of a large, easy­to-use rotary control, or by enabling the
preset reference level. For operator con­venience, the dim function allows the
monitor output level to be reduced by a
fixed dB amount. The mute all function
disables the monitor outputs by activating
the mute relays on the Model 58 Central
Controller. A push-button switch and two
LEDs are used to select the desired moni­tor output—either A or B.

Figure 1. Model 58 Central Controller Front Panel

Main input

trimpots

Insert 1

return trimpots

Figure 2. Model 58 Central Controller Back Panel

AC mains

connection

To/from

Model 591

Control

Console

Remote

contact and

level control

return trimpots

inputs

Insert 2

Monitor output

trim pots

output, meter

output, and

bypass input

connections

Monitor

Insert send

and return

connections

Configuration
DIP switches

Data

active LED

Main input

connections

Power

present LED

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Page 8 Studio Technologies, Inc.

Output channel

mute/solo

Mute/solo

mode select

Inserts 1 & 2

Input

Sources

1-4

Figure 3. Model 591 Control Console Front Panel

Input source

presets

Remote control
input
activity LED

Monitor Output

• Output A/B select

• Reference level

• Mute all

• Dim

• Rotary level control

The StudioComm’s two insert sections
are directly accessible using push-button
switches. While they can perform a stan­dard insert action, they can also be used
to provide a wide range of muting, routing,
and summing functions. Each insert can
be configured, on a per-channel basis, to
act in one of four modes: Mute, maintain
connection of the normal signal, insert the
return signal in place of the normal signal,
or sum the return signal with the normal
signal.

Control of individual monitor output chan­nels is provided by the mute/solo section.
One push-button switch sets the operating
mode for either mute or solo. In the mute
mode, an individual channel can be muted
or unmuted as required. In the solo mode,
a channel can be monitored while the
other is automatically muted. The flexibility
of having both mute and solo available
allows an operator to quickly select the

most comfortable and productive operating
mode.

A major strength of the Model 591 is the
ability to configure, under software control,
many operating parameters. During initial
installation the Model 591 is “taught” how it
should function. All configuration param­eters are stored in non-volatile memory.

The Model 591 Control Console connects
to the Model 58 Central Controller using
a standard 9-pin D-subminiature cable.
Power for the Model 591 is provided by
the Model 58. The Model 591 generates
MIDI system-exclusive messages to con­trol the Model 58. Remote control signals
connect to the Model 58, then travel on
to the Model 591 via pins in the 9-pin
interconnecting cable.

Remote Control Capability

Three remote control functions are pro­vided: Contact input 1, contact input 2, and

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 9

level. Contact input 1 can be configured
as either a remote mute all or a remote
bypass function. Contact input 2 can be
used to remotely enable insert 1 or 2, or
to activate the dim function. Using a stan­dard linear-taper potentiometer, a remote
level control can be implemented; no
special optical encoder or buffer circuitry
is required.

The remote control functions were specifi­cally included to support external functions
such as talkback or intercom. They also
allow the creation of secondary monitoring
positions. Producers, directors, or other
persons who deem themselves to be
important, often find this to be convenient.
Provision has been made in the Studio­Comm’s operating software to ensure that
critical listening is not affected by remote
activity.

Remote Control

Provision has been made to allow remote
control of several system functions. Con­tact input 1 allows remote activation of the
mute all or bypass functions. Contact input
2 allows remote activation of the insert 1,
insert 2, or dim functions. The level control
input allows remote control of the monitor
output level. The exact functioning of the
remote control inputs is dependent upon
the configuration of Model 591 Control
Console parameters. Refer to the Configu­ration section of this guide for details.

Remote control of mute all or dim is pro­vided to allow a variety of applications to
be supported. Placing a mechanical switch
adjacent to a telephone, allowing person­nel to conveniently mute the monitor
loudspeakers, is a perfectly acceptable
application. Allowing a talkback system
to automatically dim the monitor loud­speakers is another typical application.

Applications

Inserts

The Model 58 insert sections are applic­able for far more than the usual console­provided insert functions. Under control
of the Model 591 Control Console, each
channel of each insert section can inde­pendently function in one of four modes:
Mute the normal signal flow, maintain
the normal signal flow, replace the normal
signal with the return signal, or sum
(combine) the return signal with the nor­mal signal. (Note that in all cases the
insert send signal will remain active.) With
this flexibility the inserts can be used for
a variety of insert, routing, and mixing
functions.

Remote control of the bypass function is
specifically provided to support interfacing
with an associated console’s PFL/solo
system. By connecting contact input 1 to
a switch or contact closure that indicates
when the PFL/solo system is active, audio
signals connected to the bypass inputs will
automatically be monitored.

The remote level control input is one of
those features which may rarely be used,
but when needed, it’ll really be needed!
Without having support built into the
Model 591 Control Console’s hardware
and software, it would be almost impos­sible to add a remote level control later.

The remote level control input, along with
the remote mute all and dim functions,
makes it simple to create a small control
console for secondary locations. The

Issue 1, September 1999 Model 58/591 User Guide
Page 10 Studio Technologies, Inc.

remote level control input was provided
specifically to allow a producer, director,
or other “big cheese” to have their own
level control for use when previewing
audio or video work-in-process.

Note that software “smarts” in the Model
591 Control Console inhibits the use of the
remote level control any time the operator
selects the reference output level. This
ensures that the calibrated monitor level
won’t accidentally be changed by some
maroon. This, along with the remote activ­ity LED indicator on the Model 591, keeps
the remote level control from doing more
harm than good.

Bypass

The bypass function was expressly pro­vided so that additional monitoring capabil­ity can be added to a facility while main­taining compatibility with existing stereo
monitoring systems. The bypass signal
source would normally be the stereo
monitor output of an audio console. During
Model 58/Model 591 operation, the moni­tor outputs are connected, via electrome­chanical relays, to the Model 58’s output
circuitry. When the bypass function is
enabled, the monitor outputs disconnect
from the Model 58’s output circuitry, con­necting instead to the bypass inputs.
Activation of the bypass function can be
by means of a button on the Model 591
Control Console, or remotely using a
signal connected to contact input 1.

connections will be made. A location will
be selected for the Model 591 Control
Console, and it will be connected to the
Model 58. If required, external equipment
will be interfaced with the remote control
inputs. AC mains power will be connected
to the Model 58.

System Components

The shipping carton contains one each of
the following: Model 58 Central Controller,
Model 591 Control Console, 20-foot
(6.1m) 9-pin D-subminiature interconnect­ing cable, User Guide, and warranty card.
Units destined for North America also
include an AC mains cord. Your dealer or
distributor will provide an AC mains cord
for non-North American destination.

Mounting the Model 58
Central Controller

The Model 58 Central Controller requires
one space in a standard 19-inch (48.3cm)
equipment rack. Select a location that is
convenient to both the analog audio sig­nals and the Model 591 Control Console.
A 20-foot (6.1m) cable is supplied to
connect the Model 58 to the Model 591.
You can supply your own interconnecting
cable, however 50 feet (15.3m) is the
recommended maximum length. Secure
the Model 58 in the equipment rack using
two mounting screws per side.

Audio Connections

Audio signal connections are made by way
of three 25-pin D-sub connectors, located

Installation

In this section you will be installing the
Model 58 Central Controller in an equip­ment rack. Audio input, insert, and output

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 11

on the Model 58’s back panel. Three cable
harnesses, each with a 25-pin D-sub plug
(male) on one end and the desired con­nectors on the other end, are necessary.
These cable harnesses are not supplied

by Studio Technologies. Note that our
friends in some locations may use the
term “loom” instead of harness.

Main Inputs

The connector labeled INPUTS is used to
interface the audio sources with the eight
main input circuits. Note that when used
with the Model 591 Control Console, main
inputs 5-8 are not supported. Please refer
to Figure 4 for details on the exact “pin
out” of the D-sub connector. The electroni­cally balanced circuitry is intended for
connection to balanced or unbalanced
sources with a nominal signal level of
+4dBu. A trim potentiometer is associated
with each main input, allowing adjustment
of the input sensitivity over a ±2dB range.
The configuration sections of this guide
provides details on using the trim pots.

Signal Signal

Connection High (+) Low (–) Shield

MAIN IN 1 24 12 25
MAIN IN 2 10 23 11
MAIN IN 3 21 9 22
MAIN IN 4 7 20 8
MAIN IN 5 (Note 3) 18 6 19
MAIN IN 6 (Note 3) 4 17 5
MAIN IN 7 (Note 3) 15 3 16
MAIN IN 8 (Note 3) 1 14 2

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, connect signal high to + on the
D-sub, and shield to – on the D-sub;
leave the shield connection unterminated.

Monitor Outputs

The connector labeled OUTPUTS
provides access to the two, 2-channel
monitor outputs. Please refer to Figure 5
for details on the exact “pin out” of the
D-sub connector.

The monitor outputs are intended for
connection to audio amplifiers associated
with monitor loudspeakers, or to the inputs
of loudspeakers with integrated amplifiers.
Note that there are two monitor output
circuits which are switched, using relays,
to the 2-channel A and B output connec­tions. During operation only one set of
outputs, A or B, will be active at the same
time. An output which is not active has a
short-circuit placed across
its connections.

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 follows Tascam DA-88
convention. Standard DA-88-type wiring
harnesses are directly compatible, with the
exception of 4-40 screw threads being
required.

3) Main inputs 5-8 are not supported by the
Model 591 Control Console.

Note: While the Model 58’s electroni­cally balanced output circuits are
capable of driving loads of 600 ohms
or greater, the output level will drop
slightly as the load impedance ap­proaches 600 ohms. A 0.5dB differ­ence in output level can be expected
as the load impedance changes from
10k ohms to 600 ohms. This applies to
all of the electronically balanced output

Figure 4. Connections for Main Inputs

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Page 12 Studio Technologies, Inc.

circuits provided on the Model 58.

Signal Signal

Connection High (+) Low (–) Shield

MONITOR OUT A-1 (L) 24 12 25
MONITOR OUT A-2 (R) 10 23 11
MONITOR OUT B-1 (L) 21 9 22
MONITOR OUT B-2 (R) 7 20 8
METER OUT 1 (L) 18 6 (See Note 3) 19
METER OUT 2 (R) 4 17 (See Note 3) 5
BYPASS IN 1 (L) 15 3 16
BYPASS IN 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.

3) Meter outputs are unbalanced. Pins 6 and
17 internally connected to Model 58 shield.

Figure 5. Connections for Monitor Outputs,
Meter Outputs, and Bypass Inputs

The monitor outputs are electronically
balanced and are capable of driving bal­anced or unbalanced loads of 600 ohms
or greater. While balanced operation is
preferred, unbalanced operation does not
pose 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, and not where the cable
terminates at the far end.

Meter Outputs

The connector labeled OUTPUTS
provides access to the 2-channel meter
output. Please refer to Figure 5 for details
on the exact “pin out” of the D-sub
connector.

The same source, or sources, that feed
the monitor output feeds to meter output.
The major difference is that the meter
output is not affected by the monitor
output level control circuitry; it is pre-fader
(pre-VCA).

The meter output is intended for connec­tion to the inputs of various mechanical,
electronic, or electromechanical meter
systems. The meter output can also serve
as an additional audio output for special
applications, such as a copy or “dub”
output. In addition, the meter output
serves an important role in the input cali­bration process, which is discussed in the
Configuration section of this guide.

The meter output is unbalanced, has a
nominal level of +4dBu, and is capable
of driving loads of 600 ohms and greater.
Even if the meter output is not going to be
used during normal operation it is impor­tant to provide access to it. To correctly
and accurately calibrate the system input­to-output gain an audio level measurement
device must be able to be temporarily
connected to the meter output. While
not absolutely necessary, terminating or
routing the meter output to points on an
audio patch bay may prove very helpful
for long-term maintenance assistance.

Bypass Inputs

The connector labeled OUTPUTS pro­vides access to the 2-channel bypass
input. Please refer to Figure 5 for details
on the exact “pin out” of the D-sub connec­tor. It is usual for the source connected to
the bypass input to be from the stereo
monitor output of an audio console or
other monitoring system.

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Studio Technologies, Inc. Page 13

Warning: It is very important that
signals connected to the bypass input
be “post” a level control, i.e., attenu­ated from line level. Connecting a
standard line level audio signal can
result in damage to monitor loud­speaker 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 moni­tor speaker system’s input. This is be­cause 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.

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 op­eration, input level adjustment controls.

The insert returns are electronically bal­anced, have a nominal input level of +4dBu,
and are compatible with balanced or unbal­anced 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.

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

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

Signal Signal

no connections will need to be made.

Notes: 1) Connector type on Model 58 is 25-pin

The insert sends are electronically bal­anced, 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.

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.

To connect to an unbalanced load connect
the + terminal of the D-sub as signal high,

Issue 1, September 1999 Model 58/591 User Guide
Page 14 Studio Technologies, Inc.

Figure 6. Connections for Inserts

Remote Control Connections

The remote control input circuitry is physi­cally located in the Model 591 Control
Console. Access to the remote control
inputs is by way of the 9-conductor cable
that links the Model 591 with the Model 58
Central Controller. In fact, five of the nine
connections in this cable are dedicated for
use by the remote control inputs and have
nothing directly to do with the Model 58
Central Controller. Since all pins of the
Model 58’s two 9-pin D-sub connectors
are connected in parallel, access to the
remote control inputs is made using the
connector labeled “Loop Thru” on the
Model 58. Refer to Figure 7 for a detailed
description of the 9-pin D-sub connections.

Pin Signal Direction

1 Power Supply Common, Model 58 unit to

2 +15Vdc Model 58 unit to

3 Data Model 591 to

4 Data Common Model 591 to

5 Contact Input 1 Remote Contact to

6 Contact Input 2 Remote Contact to

7 CCW Remote Level

8 Wiper Remote Level

9 CW Remote Level

Cable Shield Model 591

Model 591

Model 58 unit

Model 58 unit

Model 591

Model 591

Potentiometer to Model 591

Level

Control

Potentiometer to Model 591

Potentiometer to Model 591

Contact input 1 and contact input 2 are
+5V logic signals which are active when
they are brought to the logic low state.
While the inputs are protected from over­current and static (ESD) discharge care
should be taken to prevent nasty signals
from reaching them. To activate contact
input 1 simply connect pin 5 to data com­mon, pin 4. To activate contact input 2
connect pin 6 to pin 4. The contact inputs
are active when held in the low state; they
can’t be configured to change states
(“latch”) in response to a logic pulse.

All that is required to add a remote level
control is to connect a commonly available
linear taper potentiometer. (Yes, use a
linear pot! Software in the Model 591
Control Console converts its performance
to logarithmic.) Any high-quality pot with a
nominal “coil” resistance of between 1k
and 25k ohms should work fine. Simply
connect the “Loop Thru” D-sub to the pot
in this fashion: Pin 7 to counterclockwise,
pin 8 to wiper, and pin 9 to clockwise. As
very little current (amps) travels through

Notes: 1) Connector type on Model 58 is 9-pin D-subminiature

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

Figure 7. Connections for Control Console and
Remote Control Inputs

the wiring and pot, there is really no practi­cal maximum cable length. Be aware that
the longer the cable run, the more chance
that an accidental short circuit could take
place. This is a serious issue, as a short
circuit could cause the monitor output level
to go to maximum.

Warning: Connecting to the remote
level control input requires very careful
attention to wiring and potentiometer
connections. Shorting pin 8 of the 9-pin
D-sub connector to common will raise
the monitor output level to maximum!
To address hearing safety issues, the
Model 591 is default configured to
disable the remote level control input.
A safe and reliable installation must be
completed prior to enabling the input.

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 15

Connecting the Model 591 to
the Model 58

A cable with 9-pin D-sub plugs (males)
on each end is used to interconnect the
Model 591 Control Console with the Model
58 Central Controller. A 20-foot (6.1m)
cable is provided with each Model 58/
Model 591 system. Connect one plug to
the Model 58 connector labeled “To/From
Control Console,” the other plug to the
Model 591.

Should a cable of different length be
required it should be wired in a one-to-one
fashion for all 9 pins. Pin 1 carries power
supply common, and must be intercon­nected using a conductor. A cable shield
connection should be connected to pin 1
at one, or both, ends.

panel (adjacent to the power entry connec­tor) for the configured voltage(s). Note
than an incorrect configuration could
seriously damage the unit. Should it be
necessary to change the unit’s operating
voltage it must be performed only at
the factory or by an authorized service
technician.

The Model 58 uses an IEC standard
connector to mate with the AC mains
cord. The wire colors in the AC mains
cord should conform to the internationally
recognized CEE color code and must
be wired accordingly:

Connection Wire Color
Neutral (N) Light Blue

Line (L) Brown
Protective Earth (E) Green/Yellow

For best performance the cable generally
should not exceed 50 feet (15.3m) in
length. The reality is that a cable much
longer in length should work, as long as
an excellent-quality cable is utilized. We
define “excellent” as extensive shielding
along with very low capacitance. The low
cable capacitance limits the amount of
data-signal waveform distortion. As far
as the maximum length, go ahead and
try it—if it works, it works!

AC Mains Power

The Model 58 is internally configured to
operate from either 100, 120, or 220/240V,
50/60Hz. Units shipped to North America
are factory selected for 120V operation.
Units bound for Japan are selected for
100V, while our friends “down under” and
in Europe receive units set for 220/240V.
Before connecting the Model 58 to mains
power, check that it is configured to match
the local mains voltage. Look on the back

Safety Warning: The Model 58 does
not contain an AC mains disconnect
switch. As such, the mains cord plug
serves as the disconnection device.
Safety consideration requires that the
plug and associated outlet be easily
accessible to allow rapid disconnect­ion of mains power should it prove
necessary.

As soon as mains power is applied, the
power-present LED on the Model 58 will
light. The Model 591 will go through its
power-up sequence lighting each LED in
a rapid sequence.

Note that any time one of the Model 58’s
configuration DIP switches is changed,
mains power must be disconnected and
reconnected. This ensures that the logic
circuitry is fully reset to match the new
operating parameters. (This is not a bug
in software—we designed it this way to

Issue 1, September 1999 Model 58/591 User Guide
Page 16 Studio Technologies, Inc.

ensure that performance would always be
correct!) Refer to the Configuration section
of this guide for details on setting the DIP
switches.

Note that any time one of the Model 58’s
DIP switches is changed the data LED,
located to the right of the switches, will
flash. This is normal, being provided for
factory confirmation of correct switch
operation.

Configuration

After the physical installation has been
completed, several configuration issues
must be addressed. On the Model 58
Central Controller, the unit ID and operat­ing mode must be set. In addition, the
main input, insert return, and monitor
output signal levels must be calibrated
using trim potentiometers. As a final step,
the operating parameters of the system
will be set using the Model 591 Control
Console’s configuration mode.

Model 58 DIP Switches

The Model 58 Central Controller must
be “taught,” using the front panel DIP
switches, its unit ID and operating mode.
This is required to support operation with
the Model 591 Control Console. DIP
switches 1-4 provide the Model 58 with
its unit identification number. To support a
Model 591 the unit ID must be one, which
is selected by setting all four switches to
the off (down) position. DIP switches 5 and
6 set the Model 58’s operating mode. To
the support the Model 591 switch 5 must
be in the off (down) position, while switch
6 must be in the on (up) position. DIP
switches 7 and 8 are not currently sup­ported by the Model 58, but are best left in
the off (down) position. So to summarize,
to support a Model 591 Control Console
requires DIP switches 1-5 and 7-8 to be in
the off (down) position; switch 6 must in
the on (up) position.

Once the DIP switches have been cor­rectly set the AC mains power must be
disconnected, then reconnected. This
causes the previous configuration to be
erased, and the new one implemented.
Failure to perform this step will prevent
the Model 58 from reacting to changes
made to the DIP switches.

Failure to perform a fresh “power up”
after changes have been made to
the DIP switches will prevent correct
operation!

Level Calibration

Fourteen multi-turn trim potentiometers
grace the front panel of the Model 58
Central Controller. Eight are provided
for the main inputs, four for the insert
returns, and two for the monitor outputs.
Taking time to carefully adjust the trim
pots will ensure that accurate monitoring
can take place. Each trim pot allows an
adjustment range of ±2dB, which is spread
over the trim pot’s 15 turns. Calibrating
the levels down to a tenth of a dB is easily
performed.

The meter outputs are used as the mea­suring point when adjusting 12 of the 14
trim pots. Unless calibrated level meters
are already connected to the meter out­puts, an external audio level meter is
required. In addition, the audio sources
connected to the main inputs must be
configured to generate steady signals at
nominal operating level. Those interested

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 17

in where the trim pots are located in the
circuitry, and why the meter outputs are
specified as a measurement point, should
refer to the Model 58 Block Diagram,
available from Studio Technologies, Inc.

Main Input Trim Pots

This first procedure will ensure that the
Model 58 main inputs are level matched
against each other. It is assumed that
calibrated metering devices are not al­ready connected to the meter outputs.

1. On the Model 58, connect the audio
level meter to meter output 1.

2. Using the Model 591 Control console,
select main input 1 to be routed to the
left monitor output. Be certain that
inserts 1 and 2 are not enabled. En­able the mute all function, ensuring
that you won’t have to hear a steady
tone during the entire procedure!

3. Confirm that the audio source con­nected to main input 1 is generating a
steady signal at precisely its reference
level. (This is assumed to be nominally
+4dBu.)

4. Observing the level meter, adjust main
input trim pot 1 to give a +4dBu level
at meter output 1.

5. Repeat steps 1-4 for main inputs 2, 3,
and 4.

Insert Return Trim Pots

Describing the calibration process for the
insert returns is a bit more difficult as the
exact implementation of the insert sections
is dependent upon the specific installation.
The goal is to have no unwanted level
change to occur when switching an insert
section between disabled and enabled.

Note that the insert sends are not cali­brated for a precise +4dBu nominal level.
Trim pots on the insert returns allow level
inaccuracies in the insert sends, as well as
the connected device’s input and outputs,
to be accounted for.

The following procedure would be appro­priate when an insert section is configured
to place another device in the audio path,
replacing the original. This procedure
assumes that main input calibration has
already been performed. It is also as­sumed that calibrated metering devices
are not permanently connected to the
meter outputs.

1. On the Model 58, connect the audio
level meter to meter output 1.

2. Using the Model 591 Control console,
select main input 1 to be routed to the
left and right monitor outputs. Confirm
that inserts 1 and 2 are disabled.
Enable the mute all function, ensuring
that you won’t have to hear a steady
tone during the entire procedure!

3. Confirm that the audio source con­nected to main input 1 is generating a
steady signal at precisely its reference
level.

4. Observing the level meter, confirm that
the output level is exactly +4dBu. (If
this is not the case, the main input trim
pot must be re-calibrated.)

5. Using the Model 591 Control Console,
enable insert 1.

6. Observing the level meter, adjust
the trim pot associated with insert 1,
return 1 to give a +4dBu level at
meter output 1.

7. Repeat steps 4, 5, and 6 for insert 1,
return 2.

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Page 18 Studio Technologies, Inc.

8. If insert 2 is being utilized, repeat the
procedure for its two return trim pots.

Monitor Output Trim Pots

A trim potentiometer is associated with
each of the two monitor output circuits.
Note that while there are two 2-channel
monitor output connections—A and B—
there are only two output circuits. Relay
contacts are used to switch the output
circuits between the A and B connections.
Installation-specific requirements will
dictate how the monitor output trim pots
need to be adjusted. In most cases the
trim pots will be adjusted to give exactly
the same output level on the two monitor
output channels. Other installations may
require the trim pots to be adjusted in
reference to the outputs of the audio
power amplifiers. For this discussion, we’ll
describe how to match the output levels of
the monitor outputs. Note that this proce­dure assumes that input calibration has
already been performed.

1. Start by turning off the AC mains
power on the audio power amplifier. If
loudspeakers with integrated amplifiers
are being used, turn them off too. This
“power down” is critical, ensuring that
high-level test signals do not get sent
to the loudspeakers. Don’t mess
around—turn off the amps now!

2. Confirm that the audio source con­nected to main input 1 is generating a
steady signal at precisely its reference
level.

3. Using the Model 591 Control Console,
select main input 1 as the audio
source for the left and right monitor
outputs. Ensure that other inputs are
off. Enable monitor output A. Confirm
that inserts 1 and 2, as well as the

mute all and dim functions are disabled.
Slowly turn the rotary level control
clockwise. If audio is heard, stop raising
the level and turn off any active amplifi­ers. Turn the level control until it is fully
clockwise, providing the maximum
monitor output level.

4. Connect the precision audio level
meter to channel 1 of monitor output A.

5. Observing the level meter, adjust
monitor output trim pot 1 to give
exactly +4dBu.

6. Disconnect the level meter and connect
it to channel 2 of monitor output A.

7. Observing the level meter, adjust the
monitor output 2 trim pot to give
exactly +4dBu.

8. On the Model 591 Control Console,
turn the output level control to the fully
counterclockwise position.

9. After confirming that the level control
is fully counterclockwise, activate AC
mains power on the audio amplifier
or amplified speakers.

Model 591 Operating
Parameters

Many StudioComm functions can be config­ured to meet the exact needs of your instal­lation. Here’s an overview of what you can
configure:

• Input source presets

• Insert operation

• Monitor output mode

• Power-up mute mode

• Channels selected for bypass and

bypass mode

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 19

• Reference level

Insert Operation

• Dim level

• Remote contact inputs and level control
The Model 591 Configuration Charts,

located at the end of this section, give
details on how each configuration param­eter is set. An overview of the parameters
is provided in the following paragraphs.

Entering the Configuration Mode

A small button is located on the back of
the Model 591 Control Console, adjacent
to the 9-pin D-sub connector. Pressing
and holding this button for two seconds
places the Model 591 into the configura­tion mode. In the configuration mode the
buttons and LEDs no longer perform their
normal function, but instead allow you to
observe and change many of the operat­ing parameters. The mute/solo mode
LEDs light alternately to indicate that the
configuration mode is active. Once again
pressing and holding the configure button
returns the Model 591 to normal operation.
Note that configuration changes are stored
only after the configuration mode is exited
by pressing and holding the button.

Our apologies to those of you who find the
configure button a pain to use, but it’s
supposed to be that way! Seriously, the
top of the button is slightly recessed from
the back panel, making it harder to acci­dentally activate.

When to Use the Configuration Mode

There is no problem frequently “tweaking”
the Model 591’s operating parameters to
achieve the desired performance. The
non-volatile memory chip used to store
the configuration is rated for thousands of
read and write cycles, and has a retention
time rated in years.

Configuring the insert sections is an excel­lent test of your manual dexterity. If you
have any doubts about your ability, don’t
chew gum at the same time! The insert
sections are unique in their ability to be
configured on a channel-by-channel basis.
Each channel of each insert section can
be independently set for one of four oper­ating modes: Mute normal signal, maintain
normal signal flow, replace the normal
signal with the insert return signal, or mix
the insert return signal with the normal
signal. A detailed explanation of each
mode follows:

Mode 1: Mute normal signal. In this mode
no signal flows through the insert section.
This is effectively a channel mute function.
The insert send continues to be active, but
the insert return is not active.

Mode 2: Maintain normal signal flow. In
this mode the normal audio signal contin­ues to flow through the insert section. This
is effectively a “no-insert function” function!
The insert send continues to be active, but
the insert return is not active.

Mode 3: Replace the normal signal with
the insert return signal. This is the conven­tional insert function that most audio
consoles provide. The normal signal no
longer flows through the insert section.
The return signal is connected into the
signal path. The insert send continues
to be active.

Mode 4: Mix the insert return signal with
the normal signal. In this mode the normal
signal continues to flow through the insert
section, with the insert return signal mixed
(summed) with it. No level change is per­formed, they are mixed at nominal level.

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Any level reduction required to prevent
“buildup” needs to be done externally.
The insert send continues to be active.

A special mode has been included to
allow an insert section to be disabled
from operation. This is accomplished
by configuring all eight channels associ­ated with each insert section to mode 2,
maintain normal signal flow. With this
configuration an operator can press the
associated insert button “till the cows
come home” and the function will never
activate. This is another attempt at making
the Model 591 “idiot proof.” The factory
default configuration has the two insert
functions disabled.

Monitor Output Mode

While the Model 58 Central Controller
supports the connection of two sets of
monitor loudspeakers, often only the A
output will be used. The monitor output
A/B select button on the Model 591 Con­trol Console can be disabled, preventing
an operator from selecting output B. Only
the A LED will be lit, and the button will be
inactive. The factory default configuration
is for monitor output to follow A/B select.

Power-up Mute Mode

By factory default, upon application of AC
mains power the monitor outputs remain
muted until a power-up sequence has
been performed. Then the monitor outputs
are returned to their respective states as
left at the time of the previous loss of AC
mains power. There may be special uses
where having the monitor output channels
remain muted until an operator manually
presses the mute all button is desired.
Use the configuration button to select the
desired power-up mute-all operation.

Remote Level Control

Two configuration choices are associated
with the remote level control function:
Disabled and enabled. To utilize the func­tion, simply configure it for enabled; the
factory default is for remote level control to
be disabled.

Warning: It is imperative that the
wiring of the remote level control be
carefully implemented before the
function is enabled. To not do so
risks damage to the monitor loud­speakers and, more importantly, the
ears of listeners.

Channels Selected for Bypass

Each monitor output channel can be
configured to either mute, or connect to its
associated bypass input signal when the
bypass function is active. How the chan­nels are configured simply depends on
which bypass input channels have signals
connected to them.

A special mode has been included to allow
the bypass function to be disabled from
operation. To disable the bypass function,
simply select both output channels to mute
during bypass. The factory default configu­ration has the bypass function disabled.

Bypass Mode

The bypass mode can be configured to
operate in one of three modes: Monitor
output A only, monitor output B only, or
follow the state of the monitor output A/B
button. The first two modes cause their
respective monitor outputs to be active
when in the bypass mode.

Note that even if the monitor output mode
is configured for A only, setting the bypass
mode to monitor output B only will cause

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 21

monitor output B to become active when
the bypass mode is active. Also, when the
bypass mode is configured to follow the
A/B button, the monitor output mode must
be configured to allow A/B operation or
only monitor output A will be enabled
during bypass operation. The factory
default is for the bypass function to follow
the state of the monitor output A/B select
button.

Reference Level

configuration mode by pressing and
holding the configure button, located
on the Model 591’s back panel.

6. Once the configuration mode has been
entered, the monitor output signal will
mute. Press and hold the reference
button until its associated LED lights.
This will take 5 seconds. The LED
lights to indicate that a “snapshot”
of the new reference level has been
taken.

For audio-with-picture applications it’s
critical that mixing be done in reference
to a known monitor loudspeaker level. This
is often referred to as mixing to “85dB” on
the monitors. The Model 591 Control
Console allows a precise monitor output
level to be stored, and then enabled by
pressing the button labeled REF. The
factory default is for the reference level to
be set for full attenuation. Setting a usable
reference level is very simple:

1. Set up a precision sound pressure
level (SPL) measuring device at the
desired listening location.

2. Place the StudioComm system in the
normal operating mode, not the con­figuration mode. Be certain that the
reference, mute all, dim, and insert
functions are not active.

3. Use the Model 591 Control Console
to select the reference signal source,
e.g., pink noise, to the left and right
monitor outputs.

4. Observing the SPL meter, adjust the
Model 591’s rotary level control until
the desired reference level has been
reached.

5. Being careful not to touch the position
of the rotary level control, enter the

7. To store the new reference level in
memory, exit the configuration mode
by again pressing and holding the
configure button.

This level is now permanently stored as
the reference level. Only by repeating the
procedure can the value be changed.

Once the configuration mode has been
exited, the monitor output will again be­come active. Confirm that the correct level
has been stored by pressing the reference
button. The SPL meter should again
display the desired level. If not, repeat the
calibration process.

You might wonder why you have to press
and hold the reference button for 5 sec­onds before the value is stored. This is
provided specifically so that some Bozo
won’t accidentally change the ref level
while they are playing around in the con­figuration mode! You have to know the
“secret” to be able to store a new value.

Input Source Presets

The input source presets can be individu­ally configured to match commonly used
monitoring scenarios. Any, or all, of the
input routing buttons can be selected for
each of the input source presets. As an
example, the factory default for input

Issue 1, September 1999 Model 58/591 User Guide
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source preset A was selected to be: Input 1
routed to the left monitor output; Input 2
routed to the right monitor output. This
might be a typical audio source coming
from a broadcast tape playback machine,
or a satellite receiver. To cover monitoring
a secondary audio source from the same
playback machine or satellite receiver, the
factory default for input source preset B is:
Input 3 routed to left; input 4 routed to right.

A special mode has been included to allow
an input source preset to be disabled from
operation. To disable an input source
preset, simply have no input source se­lected for routing to the left or right monitor
output channels. The factory default con­figuration for input source presets C and D
are disabled.

Dim Level

Restore Factory Defaults

The restore factory defaults function is
provided primarily for factory use. In this
way a system can be shipped with the
default settings selected. While you are
welcome to use this function, be careful
that your configuration efforts are not
wasted. Specifically, note that restoring
the factory defaults configures the refer­ence level to minimum level. All the other
parameters are fairly easy to set up, but
resetting the ref level would require getting
out the SPL meter and a calibrated signal
source. This is a hassle you may not need!

The dim function is used to reduce the
monitor output level by a preset amount.
The reduction is in dB relative to the moni­tor output’s current level. Select the desired
dim level from the four that are available:
10, 15, 20, or 25dB. The factory default is
for a 15dB dim level.

Contact Input 1

Three configuration choices are associated
with contact input 1: Disabled, remote mute
all, and remote bypass. Select the desired
operating configuration. The factory default
for contact input 1 is disabled.

Contact Input 2

Four configuration choices are associated
with contact input 2: Disabled, remote
insert 1, remote insert 2, and remote dim.
Select the desired operating configuration.
The factory default for contact input 2 is
disabled.

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Model 591 Configuration—Entering and Exiting
Configuration Mode

&

Press and hold the
configure button for
2 seconds to enter or exit
the configuration mode.

These LEDs will light alternately when
the configuration mode is active.

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Model 591 Configuration—Insert 1 and 2

&

Press and hold one of the
insert buttons to allow the
display and selection of
the insert mode.

When an insert button is pressed, pressing
the output channel buttons (one at a time)
allows the display and selection of the insert
mode for that specific channel.

When an insert button and an output channel button
are pressed at the same time, the insert mode is displayed.

LED 1-L lit means mode 1: Mute normal signal flow;
LED 2-L lit means mode 2: Maintain the normal signal flow;
LED 3-L lit means mode 3: Replace the normal signal with the return signal;
LED 4-L lit means mode 4: Sum (combine) the return signal with the normal signal.

Use the buttons to select the mode.

Default: Both channels associated with both inserts are in mode 2: Maintain the normal signal flow; function

disabled.

Note 1: This is the hardest configuration to understand and perform! Two buttons must be simultaneously pressed

to display the mode; three buttons must be simultaneously pressed to change the mode. A little practice
and it will become easy.

Note 2: If both channels associated with an insert section are set for mode 2, that insert section will be set for

disabled. This feature is provided so that the operator won’t attempt to enable an unused insert, hopefully
minimizing confusion.

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Model 591 Configuration—Monitor Output Mode, Power-Up Mute
Mode, and Remote Level Control Input

When the monitor output A/B select
When the monitor output A/B select
button is pressed, these LEDs display
the monitor output mode. When LED
L is lit the mode is A only. When LED
R is lit the mode is A/B select. Use the
buttons to select the monitor output
mode.

When the monitor output A/B select
button is pressed, these LEDs
display the power-up mute mode.
When LED A is lit power-up mute
mode is disabled. When LED B is lit
power-up mute mode is enabled.
Use the buttons to select the mode.

button is pressed, these LEDs display

the status of the remote level control

input. LED C lit means that the remote

level control input is disabled. LED D

lit means that the remote level control

input is enabled. Use the buttons to

select the status.

&

Press and
hold the
monitor
output A/B
select button
to display
and select
the monitor
output mode,
power-up
mute mode,
and remote
level control
input.

Default: Monitor output mode is A/B select.

Power-up mute mode disabled.
Remote level control input disabled.

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Model 591 Configuration—Channels Selected for Bypass
and Bypass Mode

When the mute all button is pressed, these LEDs
display the monitor output channels selected for
bypass. A lit LED indicates that the channel is selected
for bypass. Use the buttons to change the configura­tion. Both LEDs flash to indicate neither channel is
selected for bypass; bypass function disabled.

When the mute all button is pressed, these LEDs display
the bypass mode. The bypass mode indicates which
monitor output will be active when the bypass function
is enabled.

LED 1-L lit means monitor output A;
LED 2-L lit means monitor output B;
LED 3-L lit means follow monitor output A/B select button.

Use the buttons to select the mode.

Default: Neither channel selected for bypass; function disabled.

Bypass mode is follow monitor output A/B select button.

Note: A special bypass mode is available. By selecting neither channel to be associated with bypass, the bypass

function will no longer be available during normal operation.

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 27

&

Press and hold the mute all
button to display and select
the channels selected for
bypass and the bypass mode.

Model 591 Configuration—Reference Level and
Input Source Preset

When the Ref button is pressed, press and
hold the L button for 5 seconds to take a
“snapshot” of the rotary level control’s
present setting. The reference LED will
light when the “snapshot” has been taken.

When the Ref button is pressed, pressing an input
source preset button (one at a time) allows the
display and selection of the input sources. All LEDs
flash to indicate no sources are selected for that
input source preset.

&

Press and
hold Ref
button to
select the
reference
level and
display and
select the
insert source
presets.

When the Ref button and an input source preset button are
pressed at the same time, the input source preset is displayed.
Use the buttons to select the desired inputs.

Default: Reference level is set for fully attenuated (minimum) monitor output level.

Input source preset A set for input 1 routed to L, input 2 routed to R.
Input source preset B set for input 3 routed to L, input 4 routed to R.
Input source preset C set for no input selected; function disabled.
Input source preset D set for no input selected; function disabled.

Note: The 5-second delay is a safety feature, ensuring that the reference level will not be accidently changed.

To permanently store the new value, you must still exit the configuration mode.
A special input source preset mode is available. By selecting no input sources to be associated with an

input source preset, that specific input source preset function will no longer be available during normal
operation.

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Model 591 Configuration—Dim Level and Contact Inputs

When the dim button is pressed, these LEDs
display the status of contact input 1. LED L and
LED R flashing means that the input is disabled.
LED L lit means that the input provides a remote
mute all function. LED R lit means that the input
provides a remote bypass function. Use the
buttons to change status.

When the dim button is pressed, these LEDs display the
status of contact input 2. LED A lit means that the input
is disabled. LED B lit means that the input provides a
remote insert 1 function. LED C lit means that the input
provides a remote insert 2 function. LED D lit means that
the input provides a remote dim function. Use the buttons
to change status.

When the dim button is pressed, these
LEDs display the selected dim level:

LED 1-L lit means 25dB dim;
LED 2-L lit means 20dB dim;
LED 3-L lit means 15dB dim;
LED 4-L lit means 10dB dim.

Use the buttons to select the dim level.

Default: 15dB dim level.

Contact input 1 disabled.
Contact input 2 disabled.

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 29

&

Press and hold the dim
button to display and
select the dim level
and contact inputs.

Model 591 Configuration—Restore Factory Defaults

&

Press and hold both insert buttons for
5 seconds to restore Model 591 factory
defaults. Once defaults have been
restored, the LEDs will light. After
buttons are released, configuration
mode will be maintained.

Factory Defaults: Both channels associated with both inserts are in mode 2: Maintain the normal signal flow;

functions disabled.
Monitor output mode is A/B select.
Power-up mute mode is disabled.
Remote level control input disabled.
No channels selected for bypass; function disabled.
Bypass mode is follow monitor output A/B select button.
Reference level is set for fully attenuated (minimum) monitor output level.
Input source preset A set for input 1 routed to L, input 2 routed to R.
Input source preset B set for input 3 routed to L, input 4 routed to R.
Input source preset C set for no input selected; function disabled.
Input source preset D set for no input selected; function disabled.
15dB dim level.
Contact input 1 disabled.
Contact input 2 disabled.

Note: The 5-second delay is a safety feature, ensuring that the factory defaults will not be accidently

restored.

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Operation

Now that you’ve installed and configured
the system, you’re ready to go. You should
find operation very easy.

Model 58 Central Controller

The Model 58 front panel contains two
LEDs. The power LED should be lit when­ever AC mains power is connected. The
data LED will light whenever a MIDI sys­tem-exclusive message matching the
Model 58’s configuration is received.

routing selected for that preset will take
effect. The LED associated with the input
preset button will remain lit until a change
has been made to the input routing. This
change can occur as a result of any one
of the input routing buttons being pressed,
or because another input source preset
has been selected. A special configuration
allows an insert source preset to be dis­abled. If this configuration has been se­lected, pressing its associated button will
result in no action occurring.

Inserts

Model 591 Control Console

StudioComm functions are controlled
using the Model 591 Control Console and,
if installed, the contact inputs and remote
level control. To make things easy to
describe, we’ve divided the functions into
six main groups: Input source selection,
inserts, monitor output general functions,
mute/solo, bypass function, and remote
controls.

Input Source Selection

Input source selection is simple. To select
an input source for routing to the meter
and monitor outputs, press one of the
input source buttons. The corresponding
LED will light to let you know that the input
has been selected. You can select more
than one button simultaneously; up to all
eight. The selected inputs will be summed
(combined) for each channel.

Input Source Preset

Activating one of the input source presets
simply requires pressing the desired
button: A, B, C, or D. When an input
source preset has been selected, its
associated LED will be lit and the input

Activating the two insert sections is as
simple as pressing the desired insert
button. When an insert function is active,
its associated LED will be lit. Because
of the flexibility that is built into the insert
functions, it may be important for an op­erator to understand how each insert
function is configured. An insert may be
configured to operate in the usual manner
(substituting a processing device into the
audio path) or may be used for a sum­ming, routing, or muting function.

A special configuration mode allows an
insert to be disabled. This would be appro­priate if an insert section was not going to
be used. In this case, pressing that insert
button would result in no action. This is the
factory default

Monitor Output General
Functions

Four buttons and one rotary control are
associated with the monitor output func­tion. The buttons are A/B output select,
reference level, mute all, and dim. The
rotary level control is used to set the
monitor output level.

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 31

A/B Output Select

The A/B button is used to select the moni­tor output to be connected to the Model
58’s output circuitry. Two LEDs are associ­ated with the button, displaying the active
output. Pressing the button “toggles”
between the A and B outputs. There is a
special configuration that allows this but­ton to be disabled. This would be appropri­ate if connections were made only to
output A. If this configuration has been
selected, pressing the A/B button will
result in no action occurring.

Reference Level

The reference level button, labeled REF,
sets the monitor output level to a preset
value. This level is normally set, at the
time of system installation, by a technician,
using a sound-pressure-level (SPL) meter.
The LED associated with the reference
level function lights steadily whenever the
function is active. When reference level
mode is active the rotary level control is
disabled, as is the remote level control
input function.

The reference LED also serves as a cali­bration aid. If the reference level mode is
not active, and the rotary level control is
set at precisely the same level as that
configured as the reference level, the
reference LED will flash. This also holds
true for the remote level control, if config­ured.

Mute All

The mute all function is highly complicated
to operate—not! Pressing the mute all
button causes the active monitor output
(A or B) to mute. The LED associated with
the mute all button will light whenever
mute all is active. Note that if mute all is
enabled via the remote mute all function,

the mute all LED will flash, along with the
remote activity LED.

Dim

The dim function is quite self-explanatory.
Press the dim button to enable the dim
mode, which will reduce the monitor output
level by a preset amount. The dim button
is always set to “latch” the function on and
off. Dim activity applies no matter whether
the monitor output level is being set by the
rotary control, the reference button, or, if
configured, the remote level control. The
dim level can be configured for 10, 15, 20,
or 25dB, so one of those values will apply
when dim is active. The LED associated
with the dim button will light whenever dim
is active. Note that if dim is enabled via the
remote dim function, the dim LED will
flash, along with the remote activity LED.

What’s not so self-explanatory is the auto­dim-off function. Whenever dim is enabled
due to the dim button being pressed, and
reference mode is not active, changing the
rotary level control or, if configured, the
remote level control, will automatically turn
off dim. The auto dim off function is a
unique attempt at protecting the health of
audio engineers. No longer will there be
a heart-stopping blast of audio when the
dim button is pressed, supposedly to
enable dim, but actually turning it off
because dim was already enabled. It’s
hard to explain unless you’ve used an
audio console and experienced this in
person—trust us, this situation does hap­pen! Auto dim off is a wonderful “real­world” function.

Note that the auto dim off function is not
active whenever dim is on due to the
remote dim function being active. This
allows remote control equipment, such

Issue 1, September 1999 Model 58/591 User Guide
Page 32 Studio Technologies, Inc.

as a talkback system, to reliably dim the
monitor outputs.

to “lock out” the local and remote level
controls.

Rotary Level Control

The rotary level control is used to manu­ally adjust the monitor output level. It is
active any time the reference level function
is not active. When the rotary level control
is set to give the same output level as the
preset reference level, the reference LED
will flash. Note that when the level control
is set to its fully counterclockwise position,
maximum attenuation is achieved, but not
a full mute. The mute all function should
be used to fully mute the monitor outputs.

The rotary level control and, if configured,
the remote level control work together in
an interesting fashion. The control which
was turned last sets the monitor output
level. This makes it very simple to move
from using one control to the other, with no
remote enable/disable buttons or switches
to activate.

As a visual aid, if the monitor output level
is changed using the remote level control,
the remote activity LED on the Model 591
will flash. This LED will continue to flash
until a monitor-output-level-related param­eter on the Model 591 changes. Level­related parameters include turning the
rotary level control, or enabling the refer­ence level, mute all, or dim functions. The
remote activity LED flashes in this manner
as a warning, preventing an operator from
wondering why the level has “mysteri­ously” changed. A change in monitor level
can have serious consequences to an
audio mix, so this LED serves as an alert
that a change has occurred. Remember,
if you are worried about the monitor level
being changed remotely during an impor­tant mix, use the reference level function

Mute/Solo

The mute/solo mode button and the two
monitor output channel buttons, along with
associated LEDs, work together to provide
excellent flexibility. The mute/solo mode
button allows the operator to select be­tween industry-standard mute and solo
functions. The mute and solo functions
use the mute relays in the Model 58 to
enable or disable output channels. Going
from mute mode to solo mode, or vice­versa, clears all active mutes or solos.
Pressing the mode button twice is a legiti­mate means of quickly clearing a muted
or soloed channel.

In the mute mode, a channel that is muted
has its associated LED turned on. In the
solo mode a channel that is soloed has its
associated LED flash on and off, while the
LED of the non-soloed channel is not lit.

Bypass Function

To enter the bypass mode, press and hold
the mute all button for 2 seconds. All LEDs
will stop lighting, except those associated
with mute all and A/B output select. The
mute all LED will activate with a “double
flash” pattern to indicate that bypass is
active. Depending on how the system was
configured, the A/B output button may, or
may not, function during bypass mode.
Note if the bypass function has been
disabled, pressing and holding the mute
all button will have no effect.

To exit the bypass mode, press and hold
the mute all button for 2 seconds. Normal
operation will then resume.

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 33

Remote Controls

Two contact signals and a potentiometer
can be connected to the system and
configured for the desired operating char­acteristics. Contact input 1 can be config­ured for remote mute all or remote bypass.
Contact input 2 can be configured for
remote insert 1, remote insert 2, or remote
dim. The remote level control function
allows a way of remotely controlling the
monitor output level.

function will flash. If dim was already active
when remote dim is activated, the LED will
change from being lit to flashing. The re­mote activity LED on the Model 591 will
flash simultaneously as confirmation
of a remote control signal being active.

Technical Notes

Monitor Output Gain Structure

When remote mute all is activated the LED
on the Model 591 associated with mute
all will flash. If mute all was already active
when the remote mute all function is
activated, the LED will change from being
lit to flashing. The remote activity LED on
the Model 591 will flash simultaneously as
confirmation of a remote control signal
being active.

When remote bypass is activated, the
mute all LED on the Model 591 will flash,
as will the remote activity LED. The A/B
output select LED will light, indicating the
active monitor output. If configured to do
so, the A/B button will continue to function
during remote bypass.

When remote insert 1 is activated the LED
on the Model 591 associated with insert 1
will flash. The remote activity LED on the
Model 591 will flash simultaneously as
confirmation of a remote control signal
being active.

When remote insert 2 is activated the LED
on the Model 591 associated with insert 2
will flash. The remote activity LED on the
Model 591 will flash simultaneously as
confirmation of a remote control signal
being active.

When remote dim is activated the LED
on the Model 591 associated with the dim

The Model 58 Central Controller’s monitor
outputs are configured for unity gain. When
the rotary level control on the Model 591
Control Console is set for maximum level
(fully clockwise) the output level is essen­tially the same as the main input level. Trim
potentiometers allow precise adjustment of
the monitor output level. This was provided
so that slight level variations caused by the
Model 58’s circuitry and the associated
power amplifiers could be “trimmed out.”

Definition of Level—dBu

Whenever possible, Studio Technologies
has opted to use the dBu designation as it
seems to be quite rational. Using dBm was
fine when all audio line outputs were termi­nated with 600 ohm loads. In this way it
was easy to say that 0dBm is 1 milliwatt
dissipated in the known load (i.e., 0dBm
across 600 ohms will measure 0.775V). In
contemporary situations an output is rarely
terminated with 600 ohms; generally 10k
ohms or higher. The dBu designation is
better because it refers to dB referenced
to 0.775V, with no reference to load
impedance. This takes into account today’s
audio scene where signals have a low
source impedance, and a high input imped­ance. The dBu designation is becoming the
standard for the professional audio industry.

Issue 1, September 1999 Model 58/591 User Guide
Page 34 Studio Technologies, Inc.

“Hot” Disconnection of the Model 591
Control Console

Should you need to relocate the Model
591 while your StudioComm system is
operating, there is no reason why you
can’t disconnect the cable, move the unit,
and then connect it again. If the Model 591
is disconnected while it is operating, the
current operating parameters are saved in
nonvolatile memory and the Model 58
Central Controller will continue to operate
as when the link was broken. No clicks,
pops, or other noises will occur when the
Model 591 is again connected. The Model
591 will go through its standard power-up
sequence, send a message to reset
power-up defaults, then send the operat­ing parameters as stored in its memory.
You may notice a brief interval of silence
while the Model 58 responds to the reset
defaults and operating parameter mes­sages.

a power-up/power-down transient protec­tion feature. This limits the chance of
damage to the monitor loudspeakers
during the time when AC mains voltage
is connected, disconnected, or has signifi­cantly changed from nominal. A combina­tion of hardware and software is used to
monitor one of the Model 58’s power
supply “rails.” Until the DC voltage ex­ceeds 81% of its nominal, electromechani­cal relays maintain a short circuit condition
on the A and B outputs. After a short delay
the relays are allowed to function normally.
Whenever the DC voltage drops below
79% of its nominal voltage, the relays
immediately go to their mute state. During
testing it was found that upon power-up
the outputs remained very quiet; during
power down a moderate “tick” was the
worst that was heard.

Power Amplifier Input Sensitivity

Optimum StudioComm performance is
obtained when the input sensitivity of the
associated audio power amplifier (or
amplified loudspeakers) is adjusted to
match the Model 58’s monitor output level.
With normal, but loud, listening levels you
should find the level potentiometer on the
Model 591 set to about the “2-’clock”
position. If you find that you don’t have to
turn up the Model 591’s control that high,
reduce the input sensitivity of the power
amplifier until you get to the 2-o’clock
position. Most power amplifiers, or ampli­fied loudspeakers, have controls on their
inputs to allow easy adjustment of the
input sensitivity.

Monitor Output Transient Protection

The Model 58 Central Controller contains

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 35

Specifications

Model 58 Central Controller

Connectors:
Audio: 3, 25-pin D-subminiature female
Control: 2, 9-pin D-subminiature female
AC Mains: 3-blade IEC-type

General Audio:
Frequency Response: 20Hz-20kHz ±0.1dB

(down 1dB @ 85kHz), monitor out
Distortion (THD+N): 0.01%, measured at 1kHz,

+4dBu, monitor out

S/N Ratio: 89dB, ref +4dBu out
Crosstalk: 78dB, ref +4dBu in

Main Inputs: 8 (4 supported when used with

Model 591 Control Console)

Type: electronically balanced
Impedance: 24k ohms
Nominal Level: +4dBu, adjustable ±2dB

Bypass Inputs: 1, 2-channel
Type: balanced, passive, no circuitry associated

with input
Switching: bypass inputs switched to monitor

outputs using sealed, bifurcated relay contacts

Inserts: 2, 2-channel
Send Type: electronically balanced
Send Nominal Level: +4dBu
Send Maximum Level: +27dBu into 10k ohms,

+26dBu into 600 ohms

Return Type: electronically balanced
Return Impedance: 24k ohms
Return Nominal Level: +4dBu, adjustable ±2dB

AC Mains Requirement:

100, 120, or 220/240V, ±10%, factory configured,
50/60Hz

Dimensions (Overall):

19.00 inches wide (48.3cm)

1.72 inches high (4.4cm)

8.75 inches deep (22.2cm)
(1 standard rack space)

Weight: 8.0 pounds (3.6kg)

Model 591 Control Console

Application: operator interface that connects to

Model 58 Central Controller

Power: provided by Model 58 Central Controller
Output Data: generates MIDI system-exclusive

messages
Remote Control Inputs: 2 contact,

1 potentiometer

Connector: 1, 9-pin D-subminiature female
Dimensions (Overall):

7.2 inches wide (18.3cm)

2.2 inches high (5.6cm)

5.4 inches deep (13.7cm)

Weight: 2.0 pounds (0.9kg)

Monitor Outputs: 2, 2-channel
Type: electronically balanced
A/B Switching: sealed, electromechanical relays,

output circuitry shared by both outputs

Nominal Level: unity gain, adjustable ±2dB
Maximum Output Level: +27dBu into 10k ohms,

+26dBu into 600 ohms

Meter Output: 1, 2-channel
Type: unbalanced
Nominal Level: +4dBu
Maximum Level: +21dBu into 10k ohms, +20dBu

into 600 ohms

Issue 1, September 1999 Model 58/591 User Guide
Page 36 Studio Technologies, Inc.

Specifications subject to change without notice.

Appendix A

Controlling the Model 58

The Model 58 Central Controller uses
MIDI system-exclusive messages to con­trol all functions. The Model 591 Control
Console is programmed to generate a
subset of what the Model 58 is capable
of doing. By using standard MIDI mes­sages, the Model 58 can be used for a
wide range of special applications. Any
device that can be programmed to send
system-exclusive MIDI messages can be
used to control the Model 58.

While it is perfectly acceptable for devices
other than the Model 591 Control Console
to generate the MIDI system-exclusive
codes to “drive” the Model 58 Central
Controller units, a hardware detail must be
noted. The architecture of the Model 58
was created so that up to 8 units could be
connected together. A standard MIDI
hardware implementation would not allow
an output to drive this number of inputs.
To solve this problem the input impedance
of the Model 58’s MIDI input was raised
from the normal 220 ohms to 2000 ohms,
and, on the Model 591, a more sophisti­cated output circuit was implemented.
The output circuit is essentially a current
source that can easily drive up to eight
of the modified inputs.

the Model 591’s output circuit, which
consists of a few low-cost components.
Alternately, the Model 58’s MIDI input
impedance can be changed to 220 ohms
by simply changing one resistor. This will
again limit the number of Model 58 units
that can be driven by a standard MIDI
output, but three or four should function
correctly. Schematic diagrams are avail­able to purchasers of StudioComm sys­tems. Contact the factory for details.

General Notes:

All MIDI messages to be acted upon are
system-exclusive type (F0H). No channel
mode, system common, or system real
time messages are utilized.

Studio Technologies, Inc. manufacturer’s
ID number is 00H 00H 56H

The Model 58’s product device ID number
is 03H.

From our very limited tests, connecting
one or two Model 58 units to a standard
MIDI output works correctly. However,
connecting more than one or two will not
work reliably, or at all. Several solutions
to this problem are available. A custom
hardware implementation can duplicate

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 37

Function: Reset to Power-Up Default Configuration

Byte Value Description
1 F0H System-Exclusive Message

st

2 00H 1
3 00H 2
4 56H 3

Byte of Studio Tech ID

nd

Byte of Studio Tech ID

rd

Byte of Studio Tech ID
5 03H Product ID (Model 58)
6 00H Function, Restore Power-Up Default Configuration
7 F7H EOX, End of System Exclusive

Notes: Action taken after message is received:

Set all input sources to off.
Set all monitor output channels to off.
Set monitor output level to minimum.
Set monitor output A/B to both off.
Set insert 1 to all normal.
Set insert 2 to all normal.
Bypass set to normal.

Issue 1, September 1999 Model 58/591 User Guide
Page 38 Studio Technologies, Inc.

Function: Input Source and Associated Channels

Byte Value Description
1 F0H System-Exclusive Message

st

2 00H 1
3 00H 2
4 56H 3

Byte of Studio Tech ID

nd

Byte of Studio Tech ID

rd

Byte of Studio Tech ID
5 03H Product ID (Model 58)
6 01H Function, Input Source and Associated Channels
7 0nH Input Source, range 1-8, 1=input source 1, 2=input source 2, etc.
8 nnH Input Channel Status Bit Map (sum values from all seven channels):

Channel 1: off=00; on=01
Channel 2: off=00; on=02
Channel 3: off=00; on=04
Channel 4: off=00; on=08
Channel 5: off=00; on=10
Channel 6: off=00; on=20
Channel 7: off=00; on=40

9 0nH Input Channel Status

Channel 8: off=0; on=1

10 F7H EOX, End of System Exclusive

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 39

Function: Monitor Output Channel Status

Byte Value Description
1 F0H System-Exclusive Message

st

2 00H 1
3 00H 2
4 56H 3

Byte of Studio Tech ID

nd

Byte of Studio Tech ID

rd

Byte of Studio Tech ID
5 03H Product ID (Model 58)
6 02H Function, Output Channel Status
7 nnH Monitor Output Channel Status Bit Map (sum values from all seven

channels):
Channel 1: off=00; on=01
Channel 2: off=00; on=02
Channel 3: off=00; on=04
Channel 4: off=00; on=08
Channel 5: off=00; on=10
Channel 6: off=00; on=20
Channel 7: off=00; on=40

8 0nH Monitor Output Channel Status

Channel 8: off=0; on=1

9 F7H EOX, End of System Exclusive

Note: Mute all function is implemented using the output A/B status command, not the

monitor output channel status command.
Bypass status takes priority over monitor output channel status.

Issue 1, September 1999 Model 58/591 User Guide
Page 40 Studio Technologies, Inc.

Function: Monitor Output Level - Normal

Byte Value Description
1 F0H System-Exclusive Message

st

2 00H 1
3 00H 2
4 56H 3

Byte of Studio Tech ID

nd

Byte of Studio Tech ID

rd

Byte of Studio Tech ID
5 03H Product ID (Model 58)
6 03H Function, Monitor Output Level - Normal
7 nnH Monitor Output Level, MSB, range 00-7F
8 0nH Monitor Output Level, LSB, range 0-1
9 F7H EOX, End of System Exclusive

Notes: Control console sends new value each time monitor output level is changed.

Monitor output level is 8-bit precision, spread over two MIDI bytes: 00H 00H
lowest; 7FH 01H highest. MIDI byte 7 is monitor output level bits 2-8; MIDI
byte 8 is monitor output level bit 1.

Dim function is performed by control console and is sent using monitor output
level command.

This function is in effect only when monitor output channel status is on and bypass
status is normal.

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 41

Function: Monitor Output Level - Reverse

Byte Value Description
1 F0H System-Exclusive Message

st

2 00H 1
3 00H 2
4 56H 3

Byte of Studio Tech ID

nd

Byte of Studio Tech ID

rd

Byte of Studio Tech ID
5 03H Product ID (Model 58)
6 04H Function, Monitor Output Level - Reverse
7 nnH Monitor Output Level, MSB, range 00-7F
8 0nH Monitor Output Level, LSB, range 0-1
9 F7H EOX, End of System Exclusive

Notes: Not sent by control console. Provided for special applications.

Output level is 8-bit precision, spread over two MIDI bytes: 00H 00H highest;
7FH 01H lowest. MIDI byte 7 is monitor output level bits 2-8; MIDI byte 8 is
monitor output level bit 1.

This function is in effect only when monitor output channel status is on and bypass
status is normal.

Issue 1, September 1999 Model 58/591 User Guide
Page 42 Studio Technologies, Inc.

Function: Monitor Output A/B Status

Byte Value Description
1 F0H System-Exclusive Message

st

2 00H 1
3 00H 2
4 56H 3

Byte of Studio Tech ID

nd

Byte of Studio Tech ID

rd

Byte of Studio Tech ID
5 03H Product ID (Model 58)
6 05H Function, Monitor Output A/B Status
7 0nH Monitor Output A/B Bit Map (sum values from both channels):

A: off=0; on=1
B: off=0; on=2

8 F7H EOX, End of System Exclusive

Notes: This function is used by monitor output channel status and bypass status.

Output A/B status is used to mute all channels by setting byte 7 to 0.

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 43

Function: Insert 1 Status

Byte Value Description
1 F0H System-Exclusive Message

st

2 00H 1
3 00H 2
4 56H 3

Byte of Studio Tech ID

nd

Byte of Studio Tech ID

rd

Byte of Studio Tech ID
5 03H Product ID (Model 58)
6 06H Function, Insert 1 Status
7 nnH Insert Bit Map (sum values from all three channels):

Channel 1: mute=00; normal=01; replace=02; sum=03
Channel 2: mute=00; normal=04; replace=08; sum=0C
Channel 3: mute=00; normal=10; replace=20; sum=30

8 nnH Insert Bit Map (sum values from all three channels):

Channel 4: mute=00; normal=01; replace=02; sum=03
Channel 5: mute=00; normal=04; replace=08; sum=0C
Channel 6: mute=00; normal=10; replace=20; sum=30

9 nnH Insert Bit Map (sum values from both channels):

Channel 7: mute=00; normal=01; replace=02; sum=03
Channel 8: mute=00; normal=04; replace=08; sum=0C

10 F7H EOX, End of System Exclusive

Issue 1, September 1999 Model 58/591 User Guide
Page 44 Studio Technologies, Inc.

Function: Insert 2 Status

Byte Value Description
1 F0H System-Exclusive Message

st

2 00H 1
3 00H 2
4 56H 3

Byte of Studio Tech ID

nd

Byte of Studio Tech ID

rd

Byte of Studio Tech ID
5 03H Product ID (Model 58)
6 07H Function, Insert 2 Status
7 nnH Insert Bit Map (sum values from all three channels):

Channel 1: mute=00; normal=01; replace=02; sum=03
Channel 2: mute=00; normal=04; replace=08; sum=0C
Channel 3: mute=00; normal=10; replace=20; sum=30

8 nnH Insert Bit Map (sum values from all three channels):

Channel 4: mute=00; normal=01; replace=02; sum=03
Channel 5: mute=00; normal=04; replace=08; sum=0C
Channel 6: mute=00; normal=10; replace=20; sum=30

9 nnH Insert Bit Map (sum values from both channels):

Channel 7: mute=00; normal=01; replace=02; sum=03
Channel 8: mute=00; normal=04; replace=08; sum=0C

10 F7H EOX, End of System Exclusive

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 45

Function: Bypass Status (Supported by Model 58 units with serial number 00315
and later.)

Byte Value Description
1 F0H System-Exclusive Message
2 00H 1st Byte of Studio Tech ID

nd

3 00H 2
4 56H 3

Byte of Studio Tech ID

rd

Byte of Studio Tech ID
5 03H Product ID (Model 58)
6 08H Function, Bypass Channel Status
7 nnH Bypass Channel Status Bit Map (sum values from all seven channels):

Channel 1: normal=00; bypass=01
Channel 2: normal=00; bypass=02
Channel 3: normal=00; bypass=04
Channel 4: normal=00; bypass=08
Channel 5: normal=00; bypass=10
Channel 6: normal=00; bypass=20
Channel 7: normal=00; bypass=40

8 0nH Bypass Channel Status

Channel 8: normal=0; bypass=1

9 F7H EOX, End of System Exclusive

Notes: Normal indicates that channel follows monitor output channel status.

Bypass status takes priority over monitor output channel status.

Issue 1, September 1999 Model 58/591 User Guide
Page 46 Studio Technologies, Inc.

Function: Input Source to Output 2 (Supported by Model 58 units with serial number
00315 and later.)

Byte Value Description
1 F0H System-Exclusive Message
2 00H 1st Byte of Studio Tech ID

nd

3 00H 2
4 56H 3

Byte of Studio Tech ID

rd

Byte of Studio Tech ID
5 03H Product ID (Model 58)
6 09H Function, Right Input Source
7 0nH Input Source, range 1-8, 1=input source 1, 2=input source 2, etc.
8 nnH Input Source Channel Status Bitmap

(sum values from all seven channels):
Channel 1: off=00; on=01
Channel 2: off=00; on=02
Channel 3: off=00; on=04
Channel 4: off=00; on=08
Channel 5: off=00; on=10
Channel 6: off=00; on=20
Channel 7: off=00; on=40

9 0nH Input Source Channel Status

Channel 8: off=0; on=1

10 F7H EOX, End of System Exclusive

Note: Using this function requires the Model 58’s front-panel-mounted DIP switches to

be set as follows: Switch 5 to off (down) and switch 6 to on (up).

Model 58/591 User Guide Issue 1, September 1999
Studio Technologies, Inc. Page 47