Operating Instruction Manual

TOA POWERED MIXER

Model MX-104

TOA ELECTRIC CO., LTD.

KOBE, JAPAN

Contents

General Description

Features

Front Panel [Names of components & their usage]

Rear Panel [Names of components & their usage]

Connection Examples

Input Connections

Block and Level Diagrams

Specifications

Characteristics Diagrams

Appearance

Precautions

1. XLR Type Audio Connector

The connectors are wired as follows.

The pin 1 is ground [shield), the pin 2 cold (low, minus), the pin 3 hot (high, plus).

2. Description of components and functions on the MX-104.

Various descriptions are applied, depending on each manufacturer. In our

Operating and Instruction Manual explanation of components and functions is made according to our usage for them.

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— 1 —

General Description

The TOA MX-104 is a very compact, four channel self-powered mixer. It was designed to deliver maximum features and performance in a cost-effective portable

PA package.

The MX-104 features four input channels, one program output, and one Foldback output. The internal amplifier is rated at 100 watts into an 8 ohm load, and 150 watts into 4 ohms.

Each input channel has an electronically balanced XLR connector, and a highimpedance unbalanced 1/4" phone jack. In addition, each channel features two-band

EQ, a pre-EQ Foldback send, and post-EQ reverb send.

The master control section features a patchable 5-band graphic equalizer, a quality 3spring reverb, a full patch bay with 1/4" phone auxiliary and RCA tape inputs, and master volume controls for Program, Foldback, and Reverb return to both. The power amp protection circuitry and autocomp compressor, both with LED's, are also located in this section.

Features

1. Four input channels

2. 100 watts into 8 ohms, 150 watts into 4 ohms

3. Patchable 5-band graphic EQ

4. Auto Comp compression unit w/LED

5. Built-in spring reverb

6. Power amp protection circuitry w/LED

7. Full patch bay

8. Aux input w/level control, RCA jacks and parallel phone 1/4" jacks.

9. Reverb level to PGM and FB

10. Independent Foldback mix.

Each Channel

1. Input level control

2. Two band EQ

3. Pre-EQ Foldback send

4. Post-EQ Reverb send

5. Low-Z electronically balanced XLR input

6. Hi-Z unbalanced 1/4" input

— 2 —

Front Panel

High Equalizer Control

(HIGH)

The high EQ control alters the high frequency response of the input channel, providing ±13dB at 10kHz, and ±15dB at 20kHz of continuously variable active shelving equalization. The "0" detented position provides flat audio response.

Low Equalizer Control

(LOW)

The low EQ control provides

±13dB at 100Hz and ±15dB at

50Hz of continuously variable active shelving equalization.

The "0" detented position provides flat audio response.

Reverb to Foldback

Control (REV TO FB)

This control adjusts the amount of reverb signal that is returned to the foldback buss and thus the level of reverb contained in the on-stage monitor mix.

Reverb/Control

(REV)

This control determines the level of signal assigned to the reverb mixing buss. Rotating the control clockwise increases the amount of reverb in that channel.

Foldback Control (FB)

The Foldback control determines the level of signal assigned to the foldback mixing buss, thus setting the level of t h a t channel in the on-stage monitor mix.

Graphic Equalizer

(EQUALIZATION)

The graphic equalizer is 5 independent active bands ( f i l t e r s ) , providing 12dB of boost or cut at each center frequency. The "0" detented position provides f l a t audio response.

Foldback Master Control (FB)

The FB master control adjusts the overall combined signal level of the four independent channel foldback sends, and thus the level of the entire on-stage monitor mix.

Aux Level Control (AUX)

This control sets the overall level of the Aux input signal.

Power Amp Compression

Indicator

(COMP)

The Comp LED lights when the internal compressor is activated.

The compressor is provided to protect speaker systems by compressing the input signal level of the power amplifier when clipping occurs in the output stage.

Frequent flashing of the LED is not reason for alarm. However, a constant or steady light indicates that the MX-104 is being overdriven and that the internal power amplifier is possibly

"under powered" for that application. The output level of the MX-

104 should be decreased until the

LED only flashes intermittently.

Power Indicator LED

(POWER)

The indicator LED lights when the power switch is "on".

Input Level Control

(LEVEL)

The level control provides continuously variable adjustment of the channel output to the program mixing buss, thus determining the level of that channel in the main sound system mix. Since the reverb signal is "post" this control, an increase in the level of the channel's output will also result in a corresponding increase in the reverb effect of that channel.

The nominal level of the input level control is at the "10" position.

High Impedance Connectors

(HIGH Z)

These connectors are unbalanced, standard 1/4" phone jacks with an input impedance of 27k ohms, and an input level of

-35dB. When a plug is inserted into the high - Z input, the corresponding XLR connector is automatically switched out of the input circuitry.

Low Impedance Connectors

(LOW Z)

The XLR connectors are low impedance, electronically balanced inputs with an input impedance of 1k ohms.

Reverb to Program Contro1

(REV TO PGM)

This control adjusts the amount of reverb signal that is returned to the program buss and thus the level of reverb contained in the main sound system.

Program Master Control

(PGM)

The PGM control adjusts the overall combined signal level of the four independent channel level controls, and thus the level of the main sound system.

Aux Input Jacks

(AUX IN)

The phone jack and RCA pin jacks are wired in parallel, w i t h an input level of -20dB. When a plug is inserted into the phone j a c k , the RCA pin jacks are automatically switched out of the AUX circuitry.

Foldback Output Jack

(FB OUT)

This jack is for connection to external power amplifiers and/ or equalizers for the on-stage monitoring system. N o m i n a l o u t p u t level is +4dB w i t h an impedance of 600 ohms. If t h e internal power amp and equalizer are to be used for the onstage monitor system, t h e FB o u t p u t should be connected to t h e GEQ i n p u t j a c k .

Program Output Jack

(PGM OUT)

The PGM Out jack is provided for connection to external equalizers and/or power amps, deriving its signal prior to the i n t e r n a l

GEQ and power amp. Nominal o u t p u t level is +4dB with an impedance of 600 ohms.

Graphic Equalizer Input Jack -

(GEQ IN)

The GEQ i n p u t jack allows t h e graphic equalizer to be used ind e p e n d e n t l y of t h e MX-104 w i t h other e x t e r n a l e q u i p m e n t , or t h e i n t e r n a l power amplifier and t h e graphic equalizer w i t h e x t e r n a l e q u i p m e n t . When a plug is inserted, the main mix from t h e program buss is d i s c o n n e c t e d from t h e graphic equalizer and the power a m p l i f i e r . The nominal input level is +4dB w i t h an i n p u t impedance of 50k ohms.

— 3 —

Graphic Equalizer Output Jack

(GEQ OUT)

This j a c k allows t h e MX-104 and t h e i n t e r n a l g r a p h i c e q u a l izer to be used w i t h an e x t e r n a l power a m p l i f i e r , or in c o n j u n c t i o n w i t h t h e GEQ in j a c k , t o be used i n d e p e n d e n t l y of all o t h e r

MX-104 c i r c u i t r y . N o m i n a l o u t p u t level is +4dB w i t h an i m p e d a n c e of 600 o h m s .

Power Amp Protection

Indicator (PROTECT)

The indicator LED lights if the power amplifier o u t p u t is shorted, if the t e m p e r a t u r e of the unit rises above acceptable levels, or if DC is drifted to the speaker outputs. If the LED should light, speaker wiring and ambient t e m p e r a t u r e of the MX-104 should be checked. If the LED remains lighted, the unit should be referred to qualified service personnel for repair.

Note:

The MX-104 p r o t e c t i o n circuitry will (1) d e t e c t ' f a u l t y conditions' within the power amplifier, (2) give a visual indication, and (3) automatically shut down until the f a u l t condition is alleviated.

This special circuitry ensures maximum reliability and virtually eliminates equipment damage due to u n s a f e or f a u l t conditions. Please refer to f a u l t p r o t e c t i o n table on page 4 for f u l l explanation of this imp o r t a n t f e a t u r e .

Power Amplifier Input Jack

(PWR IN)

The PWR Amp i n p u t jack allows the i n t e r n a l power a m p l i f i e r to be used w i t h e x t e r n a l equipm e n t . When a plug is i n s e r t e d , t h e power amp is a u t o m a t i c a l l y disconnected f r o m t h e MX-104 m i xe r section. The n o m i n a l inp u t level is +4dB w i t h an i n p u t i m p e d a n c e of 10k ohms.

Rear Panel

Power Switch (POWER)

The power switch is a threeposition type with the middle position being the "off position.

The MX-104 should be operated in the switch position which produces the lowest amount of system hum.

Speaker Jacks (SPEAKERS)

The speaker o u t p u t s are standard 1/4" phone jacks wired in parallel. Speaker cables (recommend at least #18 gauge wire) should be connected between the MX-104 and the speaker systems prior to applying power to the unit.

Caution - The MX-104 should never be operated into less t h a n a 4 ohm speaker load.

Earth Terminal (GND)

AC Power Cord

The power cord is the three-wire type with proper grounding facilities.

Caution - The ground pin should not be removed under any circumstances. If the MX-104 must be used without proper grounding facilities, a suitable grounding adapter should be utilized.

Operation of the MX-104 with proper grounding techniques will result in less system noise and greatly reduced shock hazard.

Cord Wrap

The cord wrap is provided for convenient storage of the power cord when t h e MX-104 is not in use.

Caution - The power cord should always be completely removed from the cord wrap prior to operation of the u n i t . This will insure maximum cooling of the

MX-104. For the same reason, adequate clearance should be maintained between the rear panel and any other surface (4-6 inches should do). The vents on t h e b o t t o m and top of the MX-

104 are also provided for convection cooling. These vents should be kept clear and open. Failure to do so may cause thermal shutdown of the unit.

Warning - To avoid possible equipment damage and/or personnel i n j u r y , the fuse should always be replaced with same type and rating. Using improper fuses will also void the warranty. The MX-104 should always be disconnected from AC outlet prior to changing fuses. If fuse repeatedly fails, the unit should be referred to qualified service personnel for repair.

Fault Protection Table

Fault

Excessive current due to overloads.

Short circuits

(less than 0.4-ohm)

Temperature rise of heat sink

(more than 105°C)

DC drift

Protection

Current limiter activates at less than 2 ohm.

Indication

Compressor

LED illuminates.

Current limiter activates, input signal is lowered, unit shuts down,

Input signal is lowered.

Unit shuts down.

Amp protection

LED illuminates.

Amp protection

LED illuminates.

Input signal is lowered.

Unit shuts down.

Amp protection

LED illuminates.

Action

Remove excessive loads.

Minimum speaker loads

4 ohm.

Check speaker lines/systems for shorts.

Check for adequate ventilation.

Refer to qualified service personnel.

Restoration

Automatic restoration after normal loads are obtained.

Turn o f f power switch.

Turn on into operational loads.

Automatic restoration after temperature lowers ( t o 75° - 95° C)

Automatic restoration after normal bias is regained.

— 4 —

Connection Examples

MAIN SPEAKER SYSTEM

SPEAKER SYSTEM for foldback

(Self powered speakers

TOA model SM-25A)

From Speaker jack on Rear Panel

Low Z input should be connected with low impedance (50 ohm ~ 600 ohm) microphones

— 5 —

KEYBOARD

CASSETTE TAPE DECK

for playback

MUSICAL INSTRUMENT

Input Connections

Generally speaking, there are two rules to follow when connecting equipment outputs to the inputs of other equipment.

1. Properly match the impedances of the outputs and inputs.

2. Connect low impedance outputs to high impedance inputs.

It goes without saying that not only input and output impedance matching, but also level matching should be taken into consideration. Each input channel of the MX-104 is provided with an Input Level Control that includes a negative feedback (NF) circuitry, so the usable signal level range is wide. Input impedances and levels are shown in the following table.

CONNECTION

CH1

CH4

A U X

GEQ

PWR/AMP

INPUT

LOW Z

HIGH Z

ACTUAL

LOAD

IMPEDANCE

INPUT SPECIFICATIONS

FOR USE

WITH

NOMINAL

SENSITIVITY*

(PGM OUTPUT

LEVEL +4dB)

OPEN -60dB (0.78mV) MICRO-

PHONES

LOWER IMP

LINES

LOWER IMP,

LINES

LOWER IMP,

LINES

-35dB (13.8m V)

-20dB (77.5mV)

+4dB (1.23V)

LOWER IMP,

LINES

+4dB (1.23V)

CONNECTOR

XLR TYPE NC3F

PHONE JACK

RCA PIN JACK

PHONE JACK

PHONE JACK

PHONE JACK

*Sensitivity is the level required to produce a program out level of +4dB.

*0dB is referenced to 0.775V RMS.

All XLR Type connectors are electronic balanced. Phone jack is unbalanced.

If the line going from one piece of equipment to another is long (more than 5m), we recommend that balanced outputs be connected to balanced inputs.

As is described in the beginning of the Operating Instructions Manual, the connectors of the MX-104 are wired as follows: Pin 1 is ground (shield). Pin 2 is cold (low, minus).

Pin 3 is hot (high, plus).

— 6 —

Block and Level Diagrams

BLOCK DIAGRAMS

LEVEL DIAGRAM

— 7 —

Specifications

MIXER SECTION

Frequency Response

+0, -3dB 60Hz~20kHz (input LEVEL at "5" position)

Total Harmonic Distortion

0.05% +4dB* at 1kHz.

Hum and Noise (Open)

Equivalent Input Noise

Equivalent Input Noise

-130dB* (20Hz ~ 20kHz)

-133dB* (IHF A)

All level Controls Minimum -110dB* (IHF A)

PGM Master at MAX and all input level controls minimum -90dB* (IHF A)

PGM Master at MAX and one input level control at MAX -70dB* (IHF A)

Maximum Voltage Gain

INPUT to PGM out

INPUT to FB out

INPUT to GEQ out

AUX to PGM out

Input EQ

50Hz ±15dB Shelving

20kHz ±15dB Shelving

64dB

64dB

64dB

24dB

Equalization

63Hz ±12dB Peaking

250kHz ±12dB Peaking

1kHz ±12dB Peaking

2kHz ±12dB Peaking

8kHz ±12dB Peaking

CONNECTION

CH1

CH4

AUX

GEQ

PWR/AMP

INPUT

LOW Z

HIGH Z

ACTUAL

LOAD

IMPEDANCE

INPUT SPECIFICATIONS

FOR USE

WITH

NOMINAL

SENSITIVITY*

(PGM OUTPUT

LEVEL +4dB)

OPEN -60dB(0.78mV) MICRO-

PHONES

LOWER IMP

LINES

LOWER IMP,

LINES

LOWER IMP,

LINES

LOWER IMP,

LINES

-35dB (13.8m V)

-20dB (77.5mV)

+4dB (1.23V)

+4dB (1.23V)

CONNECTOR

XLR TYPE NC3F

PHONE JACK

RCA PIN JACK

PHONE JACK

PHONE JACK

PHONE JACK

CONNECTION

PGM

GEQ

FB

ACTUAL

SOURCE

IMPEDANCE

OUTPUT SPECIFICATIONS

FOR USE WITH

NOMINAL

NOMINAL

OUTPUT LEVEL*

MAX. BEFORE

CLIP

+4dB [1.23V]

+20dB (7.75V)

+4dB (1.23V)

+4dB (1.23V)

+20dB (7.75V)

+20dB (7.75V)

CONNECTOR

PHONE JACK

PHONE JACK

PHONE JACK

POWER AMPLIFIER SECTION

Frequency Response

+0, -1dB 15Hz to 30kHz (150W RMS

Rated Power & Load

150W RMS

HOW RMS

Power Output at Clipping

1% THD, 1kHz

160W RMS 115W RMS

Total Harmonic Distortion

Less t h a n 0.1% (200mW ~ 150W RMS, 20Hz~20kHz, 4

Typically below 0.05%

Compresser Dynamic Range

Greater t h a n 26dB

Hum and Noise

At least 105dB S/N r a t i o , 20H/~20kHz

At least 109dB S/N r a t i o IHF-A weighted

Damping Factor

Greater t h a n 200

Input Sensitivity

+4dB* (1.23V)

Input Impedance

Output Connector

Phone Jack x2

Power Requirement

294 W 120V AC 60Hz

Dimensions

494(W) X 184(H) X 304(D) (19.44 X 7.24 X 11.97) ins.

Weight

1 0 k g ( 2 2 l b s )

*0dB is referenced to 0.775V RMS.

* Specifications are subject to change without notice.

— 8 —

Characteristics Diagrams

LOW Z HIGH Z IN & INPUT EQ (LEVEL Control)

HIGH Z IN. & INPUT EQ (se t at "5")

GEQ

POWER AMP POWER BAND WIDTH POWER AM P T.H.D. vs POWER OUTPUT

POWER AM P COMPRESSOR

REVERBERATION FREQUENCY RESPONSE

Appearance

— 9 —

TOA ELECTRIC CO., LTD.

KOBE, JAPAN

Printed in Japan

133-02-690-80