Nikko alpha 440 pwr sm

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ALPHA440

STEREO POWER AMPLIFIER

TYPE AND VOLTAGE

T
W-TYPE: UL and CSA type I 120V AC

E ~TYPE: NK~STD type 220V AC

SERVICE MANUAL

CONTENTS
SPECIFICATIONS ................................................................... 1
BLOCK DIAGRAM .................................................................. 2
DISASSEMBLY ..................................................................... 3
CIRCUIT DESCRIPTION .......................................................... 4 ~ 6
ALIGNMENT .................................................................... 7 ~ 9
SCHEMATIC DIAGRAM ......................................................... IO, 11
RC. BOARD .................................................................. 12~15
PARTS LOCATION ............................................................... . 16
POWER TRANSISTORS MOUNTING ASSEMBLY ....................................... . 17
PARTS LIST ................................................................. 18~ 20
SEMICONDUCTOR DATA,
TRANSISTORS .............................................................. . 21
FIELD EFFECT TRANSISTORS .................................................. . 2I
DIODES, LED'S ............................................................. . 21
ZENER DIODES ............................................................. . 21

INTEGRATED CIRCUITS .................................................... 22, 23

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3 ALPHA 44ol

SPECIFICATIONS

AMPLIFIER SECTION

Continuous Power Output per Channel:

20 N 20000 Hz (8 ohms) ..... more than 220 Watts
20 ~20000 Hz (4 ohms) ..... more than 240 Watts
1000 HZ (8 ohms) .......... more than 240 Watts
1000 Hz (4 ohms) .......... more than 240 Watts

T. H. Distortion, 8 ohms:
. no more than 0.008%

at 1 Watt Power Output ....... no more than 0.02%

at Continuous Power Output

T. H. Distortion, 4 ohms:

at Continuous Power Output . . no more than 0.02%

l. M. Distortion, 8 ohms:

at Continuous Power Output . . no more than 0.01%

at 1 Watt Power Output ....... no more than 0.02%
IHF Power Bandwidth, 8 ohms: ....... 10 ~ 70000Hz
Damping Factor at 1000 Hz, 8 ohms: . . . . more than 80
GENERAL

Power Requirement:

W-TYPE ................. AC 120V, GOHZ
E-TYPE .................. AC 220V, 50HZ
B-TYPEI ................... AC 240V, 50Hz
Power Consumption: ........... 800 W (1.25 KVAI

Ambient Temperature during Operation: . . -10 ~ 30°C

Specifications are subject to change without notice.

Frequency Response, NORMAL input, 8 ohms:

at 1 Watt Power Output . , 20 ~100000HZ +0, -1dB

Input Sensitivity for 300 Watts Power Output:
MAIN IN ....................... 1V : 2dB

Signal to Noise Ratio, IHF "A" Network:
MAIN (NORMAL, DIRECT). . . . better than 115dB

Signal to Noise Ratio, DIN Filter:
MAIN IN (NORMAL, DIRECT) . . better than 90:13

Channel Balance: ............... no more than IdB

Residual Hum and Noise, 8 ohms: . . no more than 0.4 mV

Idling Current: ................... 50 ~ 150mA
Midpoint Voltage: ................... 0 i SOmV
Muting Delay Time: ............... 2 ~ 7 seconds
Dimensions:
Width ................ 482 mm (19 inches)
Height ............. 182 mm (7 1/4 inches)
Depth ................ 460 mm (18 1/8 inch es)
Weight, without package: ......... 21.5 kg (47.3I b5)