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POWERED MIXER

Supplementary Manual for Inspection

This manual describes the inspection procedures for PA unit.

Perform adjustment and inspection described in this manual before performing inspection described in the service manua

PA 011791 .

PA

PA 011791 PA

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EMX512SC/EMX312SC

2

+B Voltage

O

Model

EMX512SC

EMX312SC

+BL Voltage

O

O

-BL Voltage

O

O

-B Voltage

O

PA UNIT INSPECTION

1. Measuring Conditions

1-1 Environment

Normal temperature: 10 to 35 degree

Normal humidity: 45 to 85 %

1-2 Power Source

Supply the power to PA unit via the PS circuit board.

1-3 Measuring Instruments

Use the reliable measuring device capable of measuring the specification values indicated in this document precisely.

1-4 Input Impedance of Measuring Instruments

Input impedance of measuring instrument should be more than 1 Mohms.

2. Inspection

2-1 Preparation

Load resistance: 4 ohms 1 %

Turn the variable resistor VR101-VR104 counterclockwise completely before supplying the power.

Unless otherwise specified, only single channel set for drive.

Unless otherwise specified, the input signal should be high quality sine wave.

For details on connection of measuring circuit, see Fig. 3-1 on page 8.

2-2 Input and Output Input of channel A : The voltage between pin 4 of CN101 and GND (pin 5 of CN101).

Input of channel B : The voltage between pin 8 of CN101 and GND (pin 9 of CN101).

Output of channel A : The voltage between W102 and GND (W103).

Output of channel B : The voltage between W101 and GND (W103).

2-3 Inspection and Adjustment

Parts related to inspection and adjustment are shown as follows. (Fig. 2-3-1)

Fig. 2-3-1

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2-8 Distortion Factor

Input the 20 kHz, 20 Hz, +7.0 dBu sine wave to channel A or channel B and check that the distortion of output is less than 0.8 %.

Note:

Finish this inspection within 30 seconds.

2-9 DC Protection

Input the 1 kHz, +2.0 dBu sine wave to channel A or channel B and check that the obtained voltage of Test Point DC (voltagebetween pin 11 and pin 2 of CN101) is within the range specified in the table 2-9-1.

Table 2-9-1

Voltage of Test Point DC

(Voltage between pin 11 and pin 2 of CN101) *

8.6 2.0 dBu

6.3 2.0 dBu

Model

EMX512SC

EMX312SC

* Measure the AC voltage.

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EMX512SC/EMX31

+B

O

EMX512SC

EMX312SC

+BL

O

O

-BL

O

O

-B

O

PA

1.

1-1

1035

4585 %

1-2

PSPA

1-3

1-4

1 M

2.

2-1

4 1

VR101VR104

3-18

2-2 A CN101 4GNDCN101 5

B CN101 8GNDCN101 9

A W102GNDW103

B W101GNDW103

2-3

2-3-1

PA Unit Top View

2-3-1

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EMX512SC/EMX31

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AB20 kHz20 Hz+7.0 dBu

0.8 %

30

2-9 DCAB1 kHz+2.0 dBuTest Point DCCN101 11

2 2-9-1

2-9-1

Test Point DC

CN101 112*

8.62.0 dBu

6.32.0 dBu

EMX512SC

EMX312SC

* AC

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3. Measuring Circuit

* Use the load resistor with tolerance within the range of 5 %.

* 5%

Fig. 3-1 3-1

Ou

tpu

tTerm

ina

l

channe

lA

Ou

tpu

tTerm

ina

l

channe

lB

Load

2200pF 22

1.5uH

4.7/3W

0.1uF/100W

0.1uF/100W

4.7/3W

4

Load

4

GND

CN301

CN303

CN302

W305

1.5uH

4.7/3W

0.1uF/100W

0.1uF/100W

4.7/3W

222200pF

PA UNITVR104

CN103

W102

W105

VR102

W107

W103

W104

W106

CN102

VR103

VR101

CN101

NCTH_pFAN_pDCCLP_BSGSIG_BMUTECLP_ASGSIG_A-15VGND+15V

SignalInput

channelA

SignalInput

channelB

100uF/50V

47k

30k

TestPoint

DC

100uF/50V

47k

47k

47k

10k/30W

5k/3W

CN415

CN405

CN406

CN407

CN408

CN409

1 2 314

10k/30W

5k/3W

+B

+BL

+GND

-BL -B

+15V

GND

-15V

POWER

LINE FILTERAC

W101

OUT

PS

SW

OUT