Wiring Diagram

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Technical STEREO INTEGRATED AMPLIFIER

Manual RA-971
Table of Contents
Specification.....................................1
Wiring Diagram ................................2
Parts List ..........................................3,4
Adjustment.......................................4
PCB Assembly .................................5,6
Schematic Diagram..........................7,8

Specification
Rated power, rms. (20-20,000 Hz, 0.03%, 8 Ohms) 60Watts
(20-20,000 Hz, 0.03%, 4 Ohms) 90 watts
Total Harmonic Distortion, (THD) ≤ 0.03%
Intermodulation Distortion, (IMD) ≤ 0.03%
Signal to Noise ratio, all inputs > 95 dB IHF A
Frequency response 10-100,000 Hz, +1, -3 dB
Tone control response
Bass ± 6 dB @ 100 Hz
Treble ± 6 dB @ 10 kHz
Input overload level, all inputs ≥ 5 volts
Power Requirement 115 volts 60 Hz
230 volts 50 Hz
Power consumption 300 watts
Dimensions (W x H x D) 440 x 92 x 347 mm
17-3/8 x 3-5/8 x 13-11/16"
Weight (net) 6.5 kg, 14.3 lb.

Serial. NO.
BUNZAN-SHINSEN-BLD. 4F 10-10 SHINSEN-CHO, SHIBUYA-KU,
Begining
TOKYO 150-0045, JAPAN
Y-309A-98061M/S-S

2
Parts List Parts List

SYMBOL PARTS NO. DESCRIPTION SYMBOL PARTS NO. DESCRIPTION SYMBOL PARTS NO. DESCRIPTION SYMBOL PARTS NO. DESCRIPTION
E-1214 PCB ASSEMBLY HEAT SINKER ASSEMBLY
C501,502 041 50BGF10M CAP,ELEC.50V10UF R507,508 054 LTMK203K9FECZ R,METAL 1% 3.9K Q617,618 032 L2SD600K-EF TRANSISTOR 012 L4TQF-21 KNOB 33F WF
C503,504 044 LFSC160V470H CAP,STYROL 160V47PF R509,510 054 LTMK2100KFECZ R,METAL 1% 100K Q623,624 033 2SC3902-RS TRANSISTOR 012 4TQF-16 PUSH BUTTON 5X10
C505,506 041 50BGF10M CAP,ELEC.50V10UF R511,512 054 LTMK202K2FECZ R,METAL 1% 2.2K Q625,626 033 2SA1507-RS TRANSISTOR 014 C-4550A09 UPPER COVER
C507-512 044 50MSAN104J CAP,FILM 50V0.1UF R513,514 054 LTMK2002KFECZ R,METAL 1% 2K Q627-630 033 L2SD1047-DE POWER TRANSISTOR 014 L4TR-2797#2 ORNAMENT SIDE BOARD
C513,514 042 LTP50V472J CAP,MYLAR 50V4700PF R515,516 054 LTMK2022KFECZ R,METAL 1% 22K Q631-634 033 L2SB817-DE POWER TRANSISTOR 014 1TQF-5 BOTTOM BOARD

C515,516 042 LTP50V152J CAP,MYLAR 50V1500PF R517-520 054 LTMK201K5FECZ R,METAL 1% 1.5K 016 TX406111 SUB PCB 015 RP-347 REAR CHASSIS
C517,518 041 50BGF10M CAP,ELEC.50V10UF R521,522 054 LTMK2015KFECZ R,METAL 1% 15K 017 3TQF-6#1 HEAT SINKER BOARD 019 4TR-2807 PLASTIC FOOT CAP
C519,520 044 LFSC160V101H CAP,STYROL 160V100PF R523,524 054 LTMK2100KFECZ R,METAL 1% 100K 019 TO-220 INSULATION SHEET(S) 022 TT-311-UR POWER TRANSFORMER
C521,522 041 50BGF10M CAP,ELEC.50V10UF R525,526 054 LTMK2150RFECZ R,METAL 1% 150R 019 TO-3P INSULATION SHEET(L) 072 L4TR-670#4 AC CORD for STD
C523,524 041 ECEA1EFS221 CAP,ELEC.25V220UF R527,528 054 LTMK201K2FECZ R,METAL 1% 1.2K 072 LC-3763 AC CORD for AUSTRALIA
OTHERS
C527,528 041 ECEA1EFS221 CAP,ELEC.25V220UF R529,530 054 LTMK2002KFECZ R,METAL 1% 2K 011 FP-483 FRONT PANEL ASSY 072 C-4572A01 AC CORD for UK
C601,602 041 50BGF4R7M CAP,ELEC.50V4.7UF R531,532 054 LTMK2100KFECZ R,METAL 1% 100K 012 L4TQF-15 POWER BUTTON 14X14 072 L4TR-1037 AC CORD for CEE
C603,604 044 LFSC160V331H CAP,STYROL 160V330PF R533,534 054 LTMK2470RFECZ R,METAL 1% 470R 012 L4TQF-18 KNOB 13F 081 LTZ-183 STYROL SIDE MOULDING
C605,606 044 LFSC160V221H CAP,STYROL 160V220PF R601,602 054 LTMK2560RFECZ R,METAL 1% 560R 012 L4TQF-19 KNOB 24F 081 SB4-01A00 INSIDE CARTON
C607,608 041 25BGF100M CAP,ELEC.25V100UF R603,604 054 LTMK2047KFECZ R,METAL 1% 47K 012 L4TQF-20 KNOB 33F WR

C609,610 044 LFSC160V331H CAP,STYROL 160V330PF R605-612 054 LTMK201K5FECZ R,METAL 1% 1.5K
C611,612 041 50BGF10M CAP,ELEC.50V10UF R613-616 054 LTMK2220RFECZ R,METAL 1% 220R
C613-616 044 LFSC160V221H CAP,STYROL 160V220PF R617,618 054 LTMF1/4-5600F R,MRS25 560R
C617,618 044 MKT18-100V104K CAP,FILM 100V0.1UF R619,620 054 LTMK2047KFECZ R,METAL 1% 47K
C901-904 043 LTC500V103 CAP,CERA.500V0.01UF R621-624 054 LTMK2100RFECZ R,METAL 1% 100R

C905,906 041 ALC20S1044DG CAP,ELEC.50V10000UF R625,626 054 LTMF1/4-6801F R,MRS25 6.8K

C907,908 041 ECEA1EFS101 CAP,ELEC.25V100UF R627,628 054 LTMF1/4-1501F R,MRS25 1.5K Adjustment
C909,910 041 ECEA1EFS471 CAP,ELEC.25V470UF R629,630 054 LTMF1/4-3302F R,MRS25 33K
Instruments : DC milli–voltmeter
C911 041 UTSS1H100 CAP,ELEC.50V10UF R631,632 054 LTMK2001KFECZ R,METAL 1% 1K
C912 041 UTSS1E221-FB CAP,ELEC.25V220UF R633,634 054 LTMK2047RFECZ R,METAL 1% 47R Notes : Prior to Bias Adjustment, run about 5minutes with rated output(8ohms) and
warm up Power Transistor and Heat Sink. Set input off.
C913 044 DE7150F472M SPARK KILLER R635,636 054 LTMK2012KFECZ R,METAL 1% 12K
D601-608 034 LT1N4148-86 DIODE R637-644 054 TNIR2-0.22J R,METAL 2W 0.22R
D609-612 034 LT1N4003-TB DIODE R645,646 054 2WS10JF R,METAL 2W 10R Coupling
Step Location Adjust Adjust for
D901 034 LBR84 POWER DIODE R647-650 054 LTMK2680RFECZ R,METAL 1% 680R
Plus Lead Minus Lead
D902 034 LT1N4003-TB DIODE R651,652 054 LTMF3301 R,METAL 3.3K
1 TP 1 TP 3 X-1214 PCB VR601
D903,904 034 TRD16JST1 ZENER DIODE R901,902 054 LTMK203K3FECZ R,METAL 1% 3.3K DC milli–voltmeter reads 8mV
D905,906 034 LT1N4148-86 DIODE R904 053 CR14-564J-A R,CARBON 560K 2 TP 2 TP 4 X-1214 PCB VR602
F601,602 036 5ST6.3 MINI FUSE 250V6.3A R905 054 1WS5.6KJF R,METAL 1W 5.6K
F901,902 036 5ST6.3 MINI FUSE 250V6.3A R906 053 CR14-681J-A R,CARBON 680R
IC501 031 OPA2604AP IC R907 053 CR14-472J-A R,CARBON 4.7K

IC502 031 NJM2114D IC R908 054 1WS1KJF R,METAL 1W 1K

Q601-604 033 LT2SC2362KAA-FG TRANSISTOR RY901 063 EG2-24NU RELAY
Q605-610 033 LT2SA1016KAA-FG TRANSISTOR S301,302 062 4TR-2781 ROTALY SWITCH(FUNCTION)
Q611,612 033 LT2SC2362KAA-FG TRANSISTOR S501 062 4TR-2780 ROTALY SWITCH(TONE)
Q613,614 033 LT2SA1208AE-RST TRANSISTOR S601 061 4TR-3302 PUSH SWITCH(SPEAKER)

Q615,616 033 LT2SC2910AE-RST TRANSISTOR S901 061 LC-4176A01T POWER SWITCH

8
Q619,620 033 T2SC3478T-LKU TRANSISTOR TH901 034 TTC-503 THERMISTOR 7
6
1 5
Q621,622 033 T2SA1376T-LKU TRANSISTOR VR501 051 C-4170A17 VARIABLE RESISTOR(VOLUME) 2
3
Q901 033 L2SD600K-EF TRANSISTOR VR502,503 051 4TR-2774 VARIABLE RESISTOR(TONE) 4
E
C
Q902 033 L2SB631K-EF TRANSISTOR VR601,602 051 LVM6CKPV1S1K SEMI-FIXED RESISTOR B OPA2604AP
E B
C 2SB631K NJM2114D C
B E
Q903 032 LT2SC536KAA-FG TRANSISTOR 065 C-3399#1 PHONE JACK 2SD600K
2SAS1016K 2SB817
R301-304 054 LTMK2001KFECZ R,METAL 1% 1K 066 4TR-2408#1 4P PINJACK(AUX,TAPE) 2SA1507
2SC2362K 2SD1047
2SC3902
R501,502 054 LEE10-151 R,METAL 150R 066 4TR-2408#3 4P PINJACK(CD,TUNER) 2SA1208
R503,504 054 LEE10-104 R,METAL 100K 067 4TR-3090 SPEAKER TERMINAL 2SC2910
R505,506 054 LTMK2680RFECZ R,METAL 1% 680R 068 LC-3963#1 LED CONNECTOR 2SA1376
2SC3478

3 4
PCB Assembly

5 6
Schematic Diagram

7 8