Nikko alpha 230 pwr sm

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ALPHA 230

ALPHA 230$

STEREO POWER AMPLIFIER

TYPE AND VOLTAGE

W-TYPE: UL and CSA type 120V AC

E -TYPE: NKESTD type 220V AC

e SERVICEMANUAL

CONTENTS
SPECIFICATIONS ........................................................... I
BLOCK DIAGRAM .......................................................... 2
DISASSEMBLY ............................................................. 3
CIRCUIT DESCRIPTION .................................................. 4~ 6
PARTS LOCATION ......................................................... 7
SCHEMATIC DIAGRAM .................................................. 8, 9
P C. BOARD .......................................................... 10,11
ALIGNMENT ........................................................... 12,13
POWER TRANSISTORS MOUNTING ASSEMBLY ............................... 14
PARTS LIST ........................................................... 15~17
SEMICONDUCTOR DATA,
TRANSISTORS ....................................................... 17
FIELD EFFECT TRANSISTOR ........................................... 17
DIODES, LED'S ...................................................... 18
ZENER DIODES ...................................................... 18

INTEGRATED CIRCUITS

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I ALPHA 230

SPECIFICATIONS

AMPLIFIER SECTION

Continuous Power Output per Channel:

20 ~ 20000 Hz (8 ohms) ..... more than 120 Watts
20 ~ 20000 Hz (4 ohms) ..... more than 130 Watts
1000 Hz (8 ohms) .......... more than 120 Watts
1000 Hz (4 ohms) .......... more than 130 Watts

T. H. Distortion, 8 ohms:
at Continuous Power Output . . no more than 0.008%

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

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: ........ 5 ~ 70000Hz
Damping Factor at 1000 Hz, 8 ohms: . . . . more than 60
GENERAL

Power Requirement:

W-TYPE ................... AC 120V, 60Hz

AC 220V, 50Hz

B-TYPE ................... AC 240V, 50Hz
Power Consumption: .............. 480 W (620 VA)
Ambient Temperature during Operation: . . -10 ~ 30°C

Specifications are subject to change without notice.

Frequency Response, NORMAL" input, Bohms:
at 1 Watt power Output. . . 10 ~100000Hz +0, -1dB

Input Sensitivity for 120 Watts Power Output:
MAIN IN ....................... 1V : 2dB

Signal to Noise Ratio, IHF "A" Network:
MAIN (NORMAL, DIRECT) . . . . better than 105dB

Signal to Noise Ratio, DIN Filter:
MAIN IN (NORMAL, DIRECT) . . betterthan QOdB

Channel Balance: ............... no more than 1dB

Residual Hum and Noise, 8 ohms: . . no more than 0.5mV

Idling Current: .................... 40 ~ 120mA
Midpoint Voltage: ................... 0 i 20mV
Muting Delay Time: ................ 3 ~ 7 seconds
Dimensions:
Width ................ 482 mm (19 inches)
Height ............... 138 mm (5 1/3 inches)
Depth ................ 344 mm (13 1/2 inches)
Weight, without package: ......... 13.5 kg (29.7 lbs)