Audio Technica AT-MX341b SmartMixer Installation And Operation Manual

AT-MX341b SmartMixer

Lockout

Manual

Priority Pre-select

1 2 3 4

-20 -10

-6

-30+3 +6

Output Level

Master

Threshold

Master

Level

Gain 1 Gain 2 Gain 3 Gain 4

Power

AUTOM ATIC MICROPHONE MIXER AT- MX341b

Selected Channel

Automatic Microphone Mixer

Installation and Operation

®

Contents

Introduction .....................................................................................................................3

What is a SmartMixer‚? .........................................................................................................3

Features ..................................................................................................................................3

Front Panel .............................................................................................................................4

Rear Panel ..............................................................................................................................5

Installation and Setup ..............................................................................................6

Priority Microphones and Lockout Bus ................................................................................6

Preamplifier Gain ...................................................................................................................7

Output Gain ............................................................................................................................7

Phantom Power .....................................................................................................................7

Output Level LED Meter ........................................................................................................8

Adjusting “Off” Attenuation .................................................................................................8

Control Voltage Out ...............................................................................................................9

Daisy-chaining Mixers .........................................................................................................10

Rack Mounting .....................................................................................................................10

Security Caps .......................................................................................................................10

Specifications ...............................................................................................................11

Caution

To prevent fire or shock hazard, do not expose this apparatus to rain or moisture.
To avoid electric shock, do not open the cabinet.
Refer servicing to qualified personnel only.
To prevent fire, do not place any naked flame sources (such as lighted candles) on this apparatus.
To prevent fire, do not cover the ventilation of this apparatus with newspapers, table-clothes, curtains, etc.
Do not expose this apparatus to drips or splashes.
Do not place any objects filled with liquids, such as vases, on this apparatus.
Do not install this apparatus in a confined space such as a bookcase or similar unit.
Install this apparatus only in places where ventilation is good.
This apparatus should be located close enough to the AC outlet so that you can easily grasp the AC adapter at any time.
In case of emergency, disconnect the AC adapter quickly.

Compliance with FCC rules (USA only)

This class B Digital device complies with part 15 of the FCC Rules. Operation is subject to the following two condi­tions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.

Caution for FCC

You are cautioned that any changes or modifications not expressly approved in this manual could void your authority
to operate this equipment.

Note: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to
part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in
a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed
and used in accordance with the instructions, may cause harmful interference to radio communications. However,
there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by turning the equipment off and on, the user
is encouraged to try to correct the interference by one or more of the following measures:

--Reorient or relocate the receiving antenna.

--Increase the separation between the equipment and receiver.

--Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.

--Consult the dealer or an experienced radio/TV technician for help.

IC statement (Canada only)

This Class B digital apparatus complies with Canadian ICES-003.
Cet appareil numerique de la classe B est conforme a la norme NMB-003 du Canada.

2

Introduction

Please Note!

This manual assumes use of microphone-level inputs and line-level output, the most typical
SmartMixer application. However, all inputs and the output may be individually switched
internally to achieve any combination of mic- and line-level input/output. See page 8 for details.

About internal adjustment

Operating personnel must not remove equipment covers. Only qualified, experienced, authorized
service personnel may remove equipment covers for any internal adjustments.

Important caution for service personnel making internal adjustments

High voltages are present when the unit’s power cord is plugged into an electrical outlet. Service
personnel should not make any internal adjustments with power cable connected. Disconnect
the power cord from its source before removing equipment cover, because of the danger of touch­ing an internal high voltage part. Also, to avoid injury, take care not to touch any sharp edges
within the unit, its top panel or interior sections.

What is a SmartMixer®?

The AT-MX341b SmartMixer®Automatic Microphone Mixer is a microprocessor controlled, auto­matic switching, four-channel microphone mixer.

The microphone inputs are XLRF-type balanced, with 12-volt phantom power available on pins 2
and 3. The output is XLRM-type balanced, non-inverting.

AT-MX341-model mixers can be daisy-chained via the included AT8325/1.0 Link Cable and special
connectors on the rear panel. The control bus and the audio are carried between mixers by the link
cable. The result is that all microphones on a multi-mixer system can be controlled by one micro­phone connected to any mixer. Since all of the mixers are independently powered, there is no
practical limit to the number of SmartMixers that can be daisy-chained.

Features

To custom-tailor conferencing needs, the mode of each microphone channel can be independently
switched via the front panel “priority pre-select” DIP switches. The combination of switch settings
results in three different modes of priority selection/operation. In any of the three modes of auto­matic operation, when everyone stops talking, the last microphone “on” will remain “on.” In a
teleconferencing, recording, or broadcast application, this feature will provide continuous room
ambience. This feature is cascaded throughout all linked mixers so that only one microphone in
the entire system will remain on.

Each input channel has an independent gain control on the front panel. Substantial gain reserve
and adjustment range permits microphones of widely differing sensitivities to be used together
successfully.

When a microphone is “off,” its input is only attenuated. This attenuation is factory set at
8 dB. The amount of “off” attenuation can be internally adjusted between 6 dB and 20 dB if
desired. (See page 8, “Adjusting ‘Off ’ Attenuation.”)

A “manual” setting on the front panel bypasses the AT-MX341b’s automatic switching and attenu­ation functions, causing the unit to behave like a conventional 4-channel mixer. In this mode, the
relative level of each microphone is strictly a function of the position of its respective front-panel
gain control.

3

Lockout

Manual

Priority Pre-select

1 2 3 4

-20 -10

-6

-30+3 +6

Output Level

Master

Threshold

Master

Level

Gain

1

Gain

2

Gain

3

Gain

4

Power

AUTOM ATIC MICROPHONE MIXER

AT- MX

341b

Selected Channel

AT-MX341b Front Panel

Power switch.

1.

Power “on” indicator.

2.

Input Gain controls.

3.
operating conditions.

Selected Channel LED indicators.

4.

Output Level LED meter.

5.
factory calibrated for an output of +4 dBm into 600 ohms (Master Level control fully
clockwise). Can be set for peak output level indication via internal switch (see page 8).

Priority Pre-select switches.

6.
channel priority over the other channels. A priority channel can not be locked out by
other channels. Any combination of priority/non-priority selections is allowed.

Master Level control.

7.
mixer’s output is necessary, carefully turn the control counter-clockwise as needed with
a small screwdriver. Once set as desired, the control may be protected from unauthorized
adjustment by covering the panel hole with a sticker provided with the security caps.
(This control does not affect the meter indication.)

Master Threshold / Manual control.

8.
for a microphone to be considered “in use.” Adjust to keep background noise level from
triggering microphones. “Manual” setting bypasses all of the SmartMixer’s automatic
functions.

Adjust inputs for microphone sensitivities and/or

Indicate which channels are “on” or “active.”

Indicates RMS output level of the mixer. “Zero” (0) level is

A switch in the “up” position assigns the respective

Normal setting is fully clockwise (full output). If reducing the

Sets the reference level that must be exceeded

➋

Lockout LED indicator.

9.
Master Threshold.

➊

Shows when lockout bus is active. Also aids in setting

➌

➎

➑

➏➍➐➒

Figure 1. Front panel

4