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Table Of Contents

Table of Contents

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Power Amplifier Part

3-1 Setting Conditions

Setting conditions are as follows unless otherwise specified.

Input terminal:

POWER AMP switch:

Output terminal:

Output Load:

INPUT CH1 - 4, CH6

LEVEL control:

3-2 Power ON Muting

The muting relay should be released 2.5 +/- 1 seconds after the power switch is turned on.

3-3 Speaker Terminal DC Voltage

When input terminals are grounded, confirm that each output terminal voltage is 0 +/- 100 mV.

3-4 Gain

Check that +22 ± 2.0dBs output voltage is obtained when a -26dBs signal is input to the input terminal. Perform

the same check under the setting conditions of POWER AMP switch at MAIN-MAIN and the output terminals at

POWER AMP 1G and POWER AMP 2B.

3-5 Frequency Response

L 13942296513

Apply a -26dBs signal to the input terminal and check that the output voltage when the signal frequency is 20Hz

and 20kHz is within +1 and -3dB ranges respectively, using the output voltage at 1kHz as reference.

3-6 Harmonic Distortion

Apply a 1 kHz sine wave signal to the input; the output level should be 300 W/4 ohms (33.0 dBs/ch); the distortion

ratio should be less than 0.5 %.

Apply a sine wave signal of 20 Hz, 1 kHz and 20 kHz separately to the input; the output level should be 150 W/4 ohms

(30.0 dBs); the distortion ratio should be less than 0.5 %.

Do this inspection within 30 seconds.

3-7 Residual Noise

Set the MASTER level controls (MONITOR and MAIN) at minimum; the residual noise at the output terminal should be

less than -65 dBs.

Note: Use DIN-AUDIO filter.

3-8 Stability

Apply a 10 kHz -26 dBs rectangular signal to the input and connect a capacitor (10 pF to 0.47 µF) parallel to the 4

ohm load resistor, or connect an inductor (10 µH to 0.47 H) serial to the 4 ohms load resistor. Confirm that the output

signal is as illustrated below.

Overshoot:

Ringing:

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Next, only connect a capacitor (10 pF to 0.47µF) to the SPEAKERS terminal as a load, and confirm that the output

is as follows:

Overshoot:

Ringing: