Protech 2000 User Manual

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PROTECH

1/06

AUTOMATIC MICROPHONE MIXER

INSTALLATION & OPERATION MANUAL

www.protechaudio.com

MODEL 2000

WITH MIX-MINUS OUTPUTS.

The Protech Audio Model 2000 Automatic Microphone Mixer is designed to be the best operating, most transparent auto-mixer, for fixed installations. From the Dugan Speech System for transparent gain-sharing, to the mix-minus output on each input channel, to the card frame mechanical packaging, the Model 2000 is constructed to provide the designer and installer with every feature needed for perfect auto-mixer installations.

Before proceeding further, please make note that the Model 2000 is shipped from the factory with all preliminary adjustments made. The gain on each input channel

is set to 50dB, the tone controls on each are set to flat, and the master output level is set to unity. The unit should be installed, turned on and listened to, before any additional adjustments are made. In many installations, no further adjustments will be required. The first feature to make note of is the patented Dugan Speech System for proper gain sharing in automatic mixing applications. This operating system, when properly implemented, results in the best, most transparent automatic mixing to be found anywhere. A short listening demonstration has impressed even the most critical audio system designers. We at Protech Audio have worked directly with Dan Dugan Sound Design, for almost 3 years, to achieve the optimum implementation of his superior auto-mixing architecture.

The second feature to be discussed is the mix-minus output on each input channel. Other systems require any number of additional pieces of equipment, like wiring matrixes, to achieve mix-minus. In the Model 2000, the mix-minus feature is inherent in the design. Up to 8 separate mix-minus outputs are inherent in each card frame assembly. In addition to the mix-minus output, each input section incorporates a number of features, to allow installations to be done quickly, with a minimum of wiring and set-up time. High-Pass filters, Bass and Treble Controls, Logic Outputs, Phantom Power, and Mute functions are built into each input channel. The output card has provision for two balanced line outputs, Auxillary Input, switch selectable Master/Slave operation, Gain Trim, Remote Volume Control, Group Mute, optional Automatic Level Control, and optional Pink Noise Generator The optional Automatic Level Control works in a very unique manner. Instead of adjusting levels at the output only, the ALC reaches back into each input channel and readjusts the gain at each input. This feature allows the mixminus to remain properly adjusted. The card frame assemblies are linkable, to create systems with up to 100 microphone inputs. The linking is accomplished by using standard DB15 cables.

Protech Audio Corp., 192 Cedar River Road, Indian Lake New York, 12842 Voice 518-648-6410 Fax 518-648-6395

INDEX

Page 2 Page 3 Page 4 Page 6 Page 7 Page 8 Page 9 Page 9 Page 10 Page 11 Page 12 Page 14 Page 16 Page 17 -

Index and Unpacking Instructions. Unpacking Instructions. Quickstart Set-Up Input Card Description. Input Card Mechanical and Connections. Output Card Description. Output Card Mechanical and Connections. Pink Noise Generator Option Using Mix-Minus Outputs. Linking Chassis' Remote Level Controls Automatic Level Control Option Using INTEGRA III SYSTEM Cards With Model 2000 Blank

Also reference application note AN2000.

The Model 2000 Automatic Microphone Mixer is shipped from the factory with all cards plugged into their proper slots. The mechanical drawings on the facing page show the position of individual types of cards. If your system required less than 8 inputs, the system is shipped with the higher number card slots empty. If your systems required more than 8 inputs, additional frames have been shipped, along with the necessary link cables.

CAUTION: The Model 2000 has been assembled and aligned at the factory. The unit should be wired, turned on, and listened to, before any field adjustments are made.

UNPACKING-

1- Remove chassis assembly from carton. 2- Open card frame front panel by loosening two thumbscrews, remove pink anti-static shipping insert and discard. 3- Count input cards, output(s) card, power supply card(s), link cables, power supply transformers, to insure correct quantities.

MOUNTING

The Model 2000 Automatic Microphone Mixer is designed to be mounted in an industry standard 19" EIA rack. Care should be taken not to mount the unit next to power supplies, power amplifiers, or other equipment which generate strong AC fields.

WIRING-

All audio inputs and output(s) should be wired using double conductor shielded cable. Logic circuits may be wired using unshielded cable.

- Page 2 -

FRONT VIEW

PRODUCT COMPONENTS

INPUT CARD SLOT

OUTPUT

CARD

SLOT

1 TO 8 INPUT CHANNELS,

SLOTS 1 THRU 8 MAY BE USED FOR OTHER INTEGRA III SYSTEM MODULES

REAR VIEW

+15

GND

-15

GND ON

MASTER

LINK

5678

POWER

SUPPLY

CARD

SLOT

18VACT AC

CT AC

GND

OUT

POWER SUPPLY, 1 PER CHASSIS

Connector Plugs Into Mating Connector On Chassis (18VACT)

MALE

LINK IN

LINK CABLE

DB15

FEMALE

LINK OUT

- Page 3 -

QUICK START SET-UP, STANDARD AUTOMIXER INSTALLS

Unpacking and Mounting -

Unpack each Model 2000 Card Frame Assembly, loosen thumbscrews and open door. Remove antistatis bubblepack and discard. Identify which card slots have microphone input cards, and which have line input cards. (See label on bottom side of each card, near handle.) Close door and mount frame in rack. Wire all inputs and outputs with double conductor shielded cable (See connection points on pages 7 & 9.)

Inputs - Microphone

Each microphone input card has gain preset at the factory. If condenser microphones are to be used, set the gain slide switch to the low position on the corresponding input card. The microphone input cards are jumpered for 15 volt phantom power. (See page 6 for details.)

Inputs - Line

Each line input card has gain preset at the factory for unity. The line input cards are designed to be used with devices such as telco echo-cancellers, compact discs, and tape players. The mode switch on each line input is factory preset to "Auto". Depending on the installation, it may be desirable to set it to "Manual". In manual mode, the automix gain function will not effect the line input gain.

Tone Controls -

Each input card has a switch selectable high-pass filter, and Bass and Treble controls. The inputs are shipped with teh high-pass filter switched out, and the tone controls set for "Flat".

Output Cards -

The output card has only slide switch, designed to set the output to Master or Slave operation. If only one chassis is to be used, no adjustment of the factory setting, Master, is necessary. If more than one chassis is to be used, consult page

11.

CAUTION: The Model 2000 has been assembled and aligned at the factory. The unit should be wired, turned on, and listened to, before any field adjustments are made.

Special Features -

The Model 2000 Automatic Mixing system contains many special features, which allow the unit to perform many special tasks, without the need for additional equipment. Each special feature and how to use it, is described in detail, on the following pages. Please see page 2, for a page index of special features.

UNBALANCED LINE

INPUT

CONNECTION

BALANCED LINE INPUT

CONNECTION

MICROPHONE INPUT

CONNECTION

UNBALANCED LINE OUTPUT

CONNECTION

HI LO SH

BALANCED LINE OUTPUT

CONNECTION

HI LO SH

- Page 4 -

- Page 17 -

USING INTEGRA III CARDS WITH MODEL 2000

QUICK START SET-UP, BLOCK DIAGRAM & CONNECTIONS

The Model 2000-CH chassis will accomodate a number of different INTEGRA III cards. Each card has a part number that starts with"2K-", to denote that it was modified at the factory, to allow operation in the Model 2000-CH chassis. All other features are identical. For instance, the Model 665 is a 1 input, 5 output audio distribution amplifier card. The Model 2K-665 is the same card, with a trace modification.

The INTEGRA III cards that are available for use with the Model 2000-CH chassis are;

2K-662 Audio Distribution Amp, 1 x 2 2K-663 Audio Distribution Amp, 1 x 3 2K-664 Audio Distribution Amp, 1 x 4 2K-665 Audio Distribution Amp, 1 x 5

2K-674 Audio Line Mixer, 2 x 1 2K-675 Audio Line Mixer, 3 x 1 2K-676 Audio Line Mixer, 4 x 1 2K-677 Audio Line Mixer, 5 x 1

NOTES:

INPUT CARD, SLOTS 1 THRU 8

EXTERNAL +48VDC

REMOTE

GAIN

CONTROL

INPUT MUTE

INPUT

-1V

+4V

MIX-MINUS INPUTS

LOGIC OUT

INPUT MUTE

15VDC

Mic/Line

Switch

30/50dB

MASTER OUTPUT CARD, SLOT 9

GAIN

BACK PANEL

GAIN TRIM

HI-PASS

FILTER

MUTE BUSSES GROUP / ALL

BACK PANEL

TREBLE

BASS

EQVCA 1

GROUP MUTE

SWITCH

Mute

CONTROL

MIX

MASTER GAIN

VCA 2

AUTO-MIX CONTROL

MAIN MIX

Not On Logging Slots

MAIN-MIX OUTPUTS

LOG/

MIX

MINUS

PRE MIX

OUT

POST MIX

OUT

DIRECT

LOGIC

OUT

GAIN

INDICATOR

OUT

2K-588 Noise Gate Ducker, 2 x 1 2K-639 Line Amp/Compressor

Other modified INTEGRA III cards are available upon request. The trimpot controls, and the 2 pin connector, on the rear of the Model 2000-CH, will not be functional when modified INTEGRA III cards are placed into that card slot. Only the 15 pin connector will remain functional, to allow termination of the inputs and outputs. An extender card, Model 516, may be required, to allow adjustment of the gain on modified INTEGRA III cards.

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15

GROUP MUTE

ALL MUTE

MASTER REMOTE CONTROL

-1V

+4V

AUX IN

BACK PANEL

MASTER

GAIN TRIM

OPTIONAL AUTOMATIC LEVEL CONTROL

Input Connections Output Connections

Remote Control Voltage for Remote Gain Control. Input Mute, Grounding Pin Mutes Channel Input. Ground. Input Hi. Input Lo. 48V Phantom From External Source. Pre Mix Out, after Remote Volume, Mute, & Tone Controls. Ground Direct MIx Minus Input (Resistor Isolate) Gain Ind. Out Logic Out, Open collector grounded when active. Post Mix Out, Used for Mix-Minus or Console Insert. Ground Mix-Minus Out Hi Mix-Minus Out Lo

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15

Remote Master In. All Mute Ground. Group Mute. Pink Noise Option Activation Do Not Use! Aux Input Hi Aux Input Lo (Ground) Do Not Use! Do Not Use! Mix 1 Out Hi. Mix 1 Out Lo. Ground. Mix 2 Out Hi. Mix 2 Out Lo.

PINK NOISE GENERATOR

EXT. SW.

- Page 16 -

- Page 5 -

AUDIO INPUTS

GAIN -

Each input card has individually adjustable gain. The gain is preset at the factory. Before any field adjustments are made to the Model 2000, it is strongly recommended that the unit be installed, wired, turned on and listened to. If additional gain adjustments are necessary, they may be made in one of two ways. (NOTE: If ALC option is used,

switch ALC to "OFF" position, before adjusting gain trimpots.)

First, there is a gain setting slide switch on the input card assembly. This switch allows the preamplifier gain to be set to either 30dB or 50dB. This switch is set to 50dB at the factory. Most applications will require the 50dB setting. The 30dB setting is recommended for condenser type microphones. Second, each input card slot has a VCA 1 gain adjustment trimpot mounted on the backplane assembly. The trimpot is set at the factory for -6dB. The gain settings correspond to "clock" positions with 12:00 being straight up. Additional settings are as follows:

7:00 = 8:00 =

9:00 = 10:00 = 11:00 = 12:00 =

1:00 =

2:00 =

3:00 =

4:00 =

5:00 =

HIGH PASS FILTER & TONE CONTROLS -

Each input card has a slide switch selectable highpass filter. Each input card slot has individual Treble and Bass controls. The Model 2000 is shipped from the factory with the high-pass filter in the "IN" position. The BASS and TREBLE tone controls are set to the "FLAT" position. Counterclockwise rotation "CUTS" frequencies, while clockwise rotation "BOOSTS" frequencies. The corner frequency of the BASS control is 315Hz, with a peak at 50Hz. The corner frequency of the TREBLE control is 1150Hz, with a peak at 10KHz.

-35dB

-33dB

-27dB

-20dB

-15dB

-6dB 0dB - Recommended +6dB +11dB +17dB +18dB

WEIGHTING CONTROL -

Each input card slot has a "WEIGHTING" control trimpot. The Model 2000 is shipped from the factory with the "WEIGHTING" control in the maximum clockwise position. Most applications will require this setting. The "WEIGHTING" control is the send for the automixing "pre-mix". Weighting reduction can be used when it becomes necessary to balance the automatic mixing action separately from the audio mix. One situation would be where one microphone is near an air vent, and the noise of the air vent makes the gain go to that microphone when no one is talking. The weight for that channel can be backed off so the automix gains balance. The ambient weighting can be skewed up to 10dB without affecting the mixing of the voice signals. The weight is normally left at maximum position (full clockwise) for maximum dynamic range in the auto mixing system.

PHANTOM POWER -

Each input card has a 3 pin terminal strip to allow jumpering for phantom power. A red push-on jumper is supplied for each input card. By placing the jumper on the #2 and #3 terminals, the card will supply 15VDC phantom power to the microphone. By placing the jumper on the #1 and #2 terminals, the card will allow 48 volt phantom power to be supplied from an external source. Each input card is individually configured. The unit is shipped with the jumper in the external 48 volt position.

MUTE, INPUT MUTE & GROUP MUTE -

Each input card has a MUTE slide switch, used for troubleshooting. Each input card has a separate mute pin. Grounding this pin will mute the input. Each input card has a slide switch that enables the card to be attached to a group mute function. Grounding the Group Mute pin on the Master card slot will mute all inputs attached to the Group Mute function. The input cards are shipped with the GROUP MUTE enabled.

AUTOMATIC/MANUAL OPERATION

Each input card has a slide switch that allows the individual card to operate automatically, or manually .

NOTES:

ALC FEATURES

AUTOMATIC LEVEL CONTROL (ALC) CARD ASSEMBLY

(Mounted on Master Output Card Assembly)

MASTER

EXTERN.

ABCDEFG-

OFF

ALC Active.......................

(Level Gate)......................

ALC Gain Indicator...........

ALC ON-OFF Switch........

RATE Trimpot..................

TARGET Trimpot.............

WINDOW Trimpot............

RATE

Indicates active ALC function N/A Displays gain reduction. Used for set-up Controls speed of ALC action. Controls desired output level. Controls "dead zone" for dynamic range function.

TARGET

WINDOW

MIX-MINUS - see page 12 mix-minus section.

- Page 6 -

- Page 15 -

AUTOMATIC LEVEL CONTROL OPTION

NOTE 1: Always turn the ALC assembly off (switch down) when adjusting

any system gain controls, including mixer inputs, master gain control, tone controls, system equalizers, and amplifiers. If this procedure is not followed, the ALC may fade the gain back up when someone speaks softly, and the system may go into feedback.

NOTE : The automatic level control card assembly has been aligned at the factory. Normally, no further adjustments are necessary.

How It Works. The ALC's function is to fade the master gain down when the speaker is too loud, and hold it there during pauses. When a quieter speaker talks, the gain will be raised again. The ALC compares the level of the mixer's output, measured with a VU meter characteristic, with a threshold set by the TARGET trimpot control. When the output level is lower than the threshold, the ALC will fade up the master gain. When the output level is higher than the threshold, the ALC will fade the master gain down. The speed of the fade is set with the RATE trimpot control. The gating action of the ALC freezes the master gain when no one is talking. Normally it is controlled by the logic outputs of the automatic mixing input channels. Whenever a yellow logic LED on any channel is on, the ALC action is allowed to adjust the output level. The yellow ALC ENABLE LED will come on when any input's logic LED is on, and indicates when the ALC is active.

Factory Settings- Recommended positions.

RATE Trimpot = 12:00, Counterclockwise = Slower TARGET Trimpot = 9:00, Counterclockwise = Downward WINDOW Trimpot = 12:00, Counterclockwise = More Dynamic range

ALIGNMENT PROCEDUREUnplug the power supply card. Unplug and remove the master output card assembly (with ALC card assembly). Plug the extender card into the master output card slot. Plug the master output card assembly into the extender card. Plug in the power supply card With the ALC switched to "OFF", adjust all input gains, master output gains, tone controls, and adjacent channel input controls, as well as any other equipment in the signal chain (equalizers, power amps, etc.). Be sure to test with speech at all microphones after any gain adjustment. Because of the automatic mixing action, a microphone that may be ready to feed back, will not have it's gain turned up until someone speaks into it. Turn the ALC "ON". Have someone speak loudly at a microphone. Adjust the TARGET trimpot downward (counterclockwise) until the volume is reduced to a comfortable level. The middle green LED is illuminated to indicate where the target level should be. Now the ALC will fade the master gain down whenever the output level is higher than the TARGET level. When a quieter speaker talks, the gain will fade up again. Next adjust the RATE trimpot to 12:00 or lower. This will increase the ALC fade time so that it doesn't "pump". 100% counterclockwise is the slowest setting. If more dynamic range is desired, more difference between loud and soft speakers, turn the window control counterclockwise. This will create a "dead zone" below the threshold level, where the volume can vary naturally without ALC action. A WINDOW setting of 50% gives a dead zone of 5dB, and 0% (full counterclockwise), about 8dB.

Exempting Line Level Inputs From ALCSince the ALC works by varying the master gain when a logic indicator is active, removing R23 prevents the ALC from changing the gain on the line input, whenever any input becomes active.

INPUT FEATURES

INPUT CARD ASSEMBLY

GROUP MUTE DISABLE ENABLE

RED

NORMAL MUTE

YELLOW GREEN

AUTO MANUAL

A =

Switch allows individual channels to be connected to Group Mute. (Shipped "Enabled")

B =

Switch allows individual channels to be muted for troubleshooting. (Shipped "Normal")

C =

Switch allows either automatic or manual operation of individual input channels.(Shipped "Auto")

D =

High-Pass filter (Rumble). (Shipped "Out")

E =

HI-LO gain switch, 50 or 30 dB, for use with different microphone types. (Shipped "HI")

F =

Placing RED push-on shunt on pins +48 and middle, allows external 48 volt phantom to be used.

(Shipped "15V")

G =

Mic/Line switch, for determining input impedance and gain structure. (Shipped as MIC input)

H =

Factory set, to allow mix-minus output

I =

Placing RED push-on jumper determines whether pre-mix outputs are pre or post mute.

LED's =

Gain Set

Bass Control

Treble Control

Adjacent Channel Mix-Minus L

Adjacent Channel Mix-Minus R

Adjacent Channel In Adjacent Channel In

ALL ADJUSTMENTS ON

Red indicates Mute Function. Yellow indicates Logic function. Green indicates gain function.

DAUGHTER BOARD ARE

MADE AT FACTORY.

DO NOT READJUST ANY

TRIMPOTS ON DAUGHTER

BOARD

TYPICAL INPUT CONNECTION, 1 OF 8

10 11 12 13 14 15

Line---Mic

HI LO

GAIN

1 2 3 4 5 6 7 8 9

Remote Control Voltage Input Mute, Ground. Input Hi. Input Lo. 48V Phantom From External Source. Pre Mix Out Ground

Direct MIx Minus Input (Resistor Isolate)

Gain Ind. Out Logic Out Post Mix Out, Used for Mix-Minus or Console Insert. Ground Mix-Minus Out Hi Mix-Minus Out Lo

PRE MUTE POST

PHANTOM +15 +48

OUT

LOG

M/M

- Page 14 -

- Page 7 -

OUTPUT SET-UP

REMOTE VOLUME CONTROL OPTIONS

GAIN -

Each output card slot has a Master VCA 2 gain adjustment trimpot mounted on the backplane assembly. The master gain trimpot adjusts all VCA 2's together. The trimpot is set at the factory for -6dB. The gain settings correspond to "clock" positions with 12:00 being straight up. Additional settings are as follows:

7:00 = 8:00 =

9:00 = 10:00 = 11:00 = 12:00 =

1:00 =

2:00 =

3:00 =

4:00 =

5:00 =

AUXILLARY INPUT -

The Auxillary Input is an unbalanced input, designed to allow insertion of audio signals from devices such as cassette players, computers, tape machines, and CD players.

-33dB

-27dB

-23dB

-18dB

-13dB

-10dB

-5dB 0dB +4.5dB +5dB

Recommended

MASTER/SLAVE OPERATION-

Each output card has a slide switch, which determines whether the frame assembly is used as a master or slave. The slave position is used only when two or more frames are linked together. In the "MASTER" position, the frame controls the auto-mixing function for the cards within the frame, and any frames, to which it may be linked. In the "SLAVE" position the frame allows control of the auto-mixing function from an external "MASTER" frame. All of the input card signals in the "SLAVE" frame will appear on the outputs of the "MASTER" frame. The "SLAVE" frame main outputs will contain only the input signals originating within the frame.

PINK NOISE GENERATOR OPTION -

The pink noise generator option provides a pink noise signal, that is activated by a ground closure, that appears on the main output, and all mix-minus outputs. This feature is designed to provide privacy, in courtroom applications.

MODELS 2000-RVC-IN & 2000-RVC-OP

REMOTE VOLUME CONTROLS

FRONT VIEW

REAR VIEW

Single-Gang Wall Plate

- Page 8 -

- Page 13 -

REMOTE VOLUME CONTROL CONNECTIONS

OUTPUT FEATURES

Note: Models 2000-RVC-IN (Input Remote Control) & 2000-RVC-OP (Output Remote Control) are available to provide the remote control circuits described below. See next page.

Wire one resistor-potentiometer circuit for each output circuit requiring remote

level control. Turn gain trimpots on chassis full counterclockwise, on all channels having

remote level.control circuits Set all remote potentiometers to full clockwise position.

Apply AC power to external power transformer.

Adjust each input and output trimpot to required level by rotating trimpots

clockwise. Suggested settings are 1:00 for input gain trimpots, and 12:00 for the master output trimpot.

This alignment procedure will allow the installer to limit the maximum gain available to the end user.

A =

LED's =

OUTPUT CARD ASSEMBLY

SPACE RESERVED FOR

OPTIONAL ADD-ON

MASTER

AUTOMATIC LEVEL CONTROL

PC ASSEMBLY.

SLAVE.

Switch allows chassis to be linked, as master or slave unit.

Green indicates +DC power.

TYPICAL OUTPUT CONNECTOR

+15

GND

-15

GND ON

18VACT

AC CT AC

GND

MASTER

LINK

OUT

Output

12K

10K Pot

Model 2000-RVC-OP

Circuit

To Pin 1 On Ouput card connector

678

- Page 12 -

+15

-15

Input

6.8K

10K Pot

18K

Model 2000-RVC-IN

Circuit

Master Gain Set

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15

OUTPUT CONNECTOR FUNCTIONS

1 -

To Pin 1 On Input card connector

Remote Master In..............

2 -

All Mute............................

3 -

Ground...............................

4 -

Group Mute.......................

5 -

Spare..................................

6 -

N/A.....................................

7 -

AUX In HI.........................

8 -

Ground................................

9 -

N/A....................................

10 -

N/A....................................

11 -

Mix Out Hi.........................

12 -

Mix Out Lo........................

13 -

Ground...............................

14 -

Mix Out Hi.........................

15 -

Mix Out Lo........................

External DC voltage to control master output level. Grounding pin mutes all inputs. Ground. Grounding pin mutes all inputs with group mute switch in "ENABLE" position. Not Used Do Not Use! Auxillary Input High Auxillary Input Low Ground Do Not Use! Main Mix #1 Output High. Main Mix #1 Output Low. Ground. Main Mix #2 Output High. Main Mix #2 Output Low.

- Page 9 -

USING MIX-MINUS OUTPUTS

MULTI-CHASSIS LINKING CONNECTIONS

Each input channel has a discrete mix-minus output. The mix-minus output on each input card has all input signals received on the mixing buss except the signal received on that input (primary signal). In addition to the primary signal being removed on the mix-minus output, each input card has several provisions for additional signals to be removed or attenuated on the mix-minus output. Two signals are referred to as adjacent channel left, and adjacent channel right. This description is intended to describe microphones located next to each other in a room, not card slot locations in the card frame. Additional signals may be removed using the direct input, or the Model 704 Modular Matrix Mixer cards.

CONNECTION AND CONTROL DRAWING

Gain Set

Bass Control

Weighting

Treble Control

Adjacent Channel Mix-Minus L

Adjacent Channel Mix-Minus R

Adjacent Channel In L Adjacent Channel In R

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15

The drawing at the bottom of this page shows the wiring connections needed to use the mix-minus output, with adjacent channels left and right. (Note:

Depending on microphone to speaker spacing, it is not always necessary to attenuate adjacent channels.) The adjacent channels have trimpot controls

that allow the amount of signal attenuation to be adjusted. As shown below, the channel two mixminus output would have input two removed, and inputs 1 and 3 attenuated to whatever level the adjacent channel trimpots are set. The direct input allows other signals to be removed, should that become necessary. This wiring scheme would be duplicated wherever adjacent channels need attenuation.

Remote Control Voltage for Remote Gain Control. Input Mute, Grounding Pin Mutes Channel Input. Ground. Input Hi. Input Lo. 48V Phantom From External Source. Pre Mix Out, after Remote Volume, Mute, & Tone Controls. Ground Direct Mix-Minus Input (Resistor Isolate) Gain Ind. Out Logic Out, Open collector grounded when active. Post Mix Out, Used for Mix-Minus or Console Insert. Ground Mix-Minus Out Hi Mix-Minus Out Lo

On master chassis, set master/slave switch (see output section for location) to

master. On slave chassis(s), set master/slave switch to slave.

Use 2000-CA link cable to connect chassis(s).

Use Master trimpot on master chassis to adjust all input levels simultaneously.

Note: If ALC option is used, the ALC is placed on the output board of the master chassis.

MASTER CHASSIS

+15

GND

-15

GND ON

18VACT

AC CT AC

GND

MASTER

LINK

OUT

678

TYPICAL INPUT CONNECTION, 1 OF 8

INPUT 3 INPUT 1

1 2 3 4 5 6 7 8

Direct In

9 10 11 12 13 14 15

INPUT 2

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15

- Page 10 -

Direct In

POWER AMP

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15

Direct In

+15

GND

-15

GND ON

18VACT

AC CT AC

GND

MASTER

LINK

OUT

FROM ADDITIONAL CHASSIS

SLAVE CHASSIS

678

- Page 11 -

Protech 2000 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual