Sansui AU-9900A/11000A Integrated Stereo Amplifier Service Manual

Introduction

This document serves as a comprehensive service manual for the Sansui AU-9900A and AU-11000A Integrated Stereo Amplifiers. It contains essential technical data, component information, and repair guidance for qualified service personnel.

2. Specifications

Parameter	Details
Power Output (Min. RMS, both channels driven, 20-20,000Hz, <0.05% THD)	AU-9900A: 80W/ch (8Ω), 80W/ch (4Ω) AU-11000A: 110W/ch (8Ω), 110W/ch (4Ω)
Power Output (Min. RMS, both channels driven, 1,000Hz, <0.05% THD)	AU-9900A: 80W/ch (8Ω), 80W/ch (4Ω) AU-11000A: 110W/ch (8Ω), 110W/ch (4Ω)
Load Impedance	4-8Ω (SYSTEM-A or B), 8Ω (SYSTEM A+B)
Power Bandwidth	20-20,000 Hz at or below rated min. RMS power output and total harmonic distortion
Total Harmonic Distortion	Less than 0.05% at or below rated min. RMS power output
Intermodulation Distortion (70Hz:7kHz 4:1 SAMPTE method)	Less than 0.05%
Frequency Response (at 1 watt)	5 to 80,000 Hz ±1.5dB
Damping Factor	Approximately 70 at 8 ohm load
RIAA Curve Deviation (PHONO)	+0.2dB, -0.2dB (30 Hz to 15 kHz)
Input Sensitivity and Impedance (1 kHz, for rated power output)	PHONO-1: 2, 4, 8 mV/30, 50, 100 kΩ (Max. input capability: 1,000 mV at 1 kHz, <0.1% THD, PHONO-1 SENSITIVITY switch at 8 mV) PHONO-2: 2 mV/50 kΩ (Max. input capability: 250 mV at 1 kHz, <0.1% THD) TAPE-1, 2 REC (pin jacks): 150 mV/560 Ω AUX-1, 2: 150 mV/50 kΩ
Output Level (1,000 Hz)	TAPE-1, 2 REC (pin jacks): 150 mV/560 Ω PRE OUT: 1 V/560 Ω
Channel Separation (1 kHz, at rated power output)	PHONO-1, 2: better than 60dB AUX-1, 2: better than 60dB
Hum and Noise (short-circuit, A-network)	PHONO-1: 75dB (PHONO-1 SENSITIVITY Switch at 4 mV) AUX-1, 2: better than 90 dB
Controls	BASS: ±10dB (30 Hz) MIDRANGE: ±5dB (1 kHz) TREBLE: ±10dB (20 kHz) Tone selector (turnover frequency): 2, 4, 8 kHz LOW FILTER: -3dB (20, 60 Hz), 12dB/oct. HIGH FILTER: -3dB (7 kHz), 6dB/oct. MUTING: -20dB (12 kHz), 12dB/oct.
Power Requirements	100, 120, 220, 240V (50/60Hz)
Power Voltage	120V (Usable 110-130V) 60Hz (for U.S.A. & Canada only)
Power Consumption	Maximum: AU-9900A: 665 watts, AU-11000A: 915 watts Rated: AU-9900A: 340 watts 435 VA, AU-11000A: 480 watts 605 VA
Dimensions	460 mm (18 1/8") W x 176 mm (6 15/16") H x 407 mm (16 1/16") D
Weight	AU-9900A: 17.6 kg (38.8 lbs) net, 19.7 kg (43.4 lbs) packed AU-11000A: 19.2 kg (42.3 lbs) net, 21.3 kg (47.0 lbs) packed

* Design and specifications subject to change without notice for improvements.

* Illustrations may differ from originals for simplification.

1. Block Diagram

The block diagram illustrates the signal flow and main functional units of the Sansui AU-9900A/11000A integrated amplifier. It shows how input signals are processed through various stages, including the Input Selector, Tone & Filter controls, Play Mode controls (Balance, Muting), Tape Play circuits, and the Pre-Amplifier and Power Amplifier sections, before outputting to the speakers. Key protection circuits like the Power Amp. Protector and Thermal Sensor are also indicated, along with the Power Supply and Transformer.

[Block diagram illustrating signal path and main components of the integrated amplifier]

3. Parts Location & Parts List

This section details the physical layout and component identification for various circuit boards within the amplifier. Each subsection focuses on a specific circuit board (e.g., F-2569 Input Terminal & Switch Board, F-2660 Level Volume Circuit Board, F-2691 Equalizer Circuit Board, etc.), providing a conductor-side view with numbered components and a corresponding parts list with part numbers, stock numbers, descriptions, and positions.

3-1. F-2569 Input Terminal & Switch Circuit Board

This board handles input selection and various switching functions. Components include input selector switches, sensitivity switches, and pin/DIN jacks.

Parts No.	Stock No.	Description	Position
R07,08	0231202	2.0kΩ M.R.	A
S01	1190260	Input Selector Switch	A, B
S02	1110310	Pick-up Load Switch	A
S03	1110310	Sensitivity Switch	A
J01	2090030	5P DIN Socket	B
J01	2410780	6P Pin Ass'y (Type C)	B
J01	2430260	IP Jack (White)
J01	2430270	IP Jack (Red)

3-2. F-2660 Level Volume Circuit Board

This board contains the volume and tone control circuitry.

Parts No.	Stock No.	Description	Position
TR01,02	0306270.1	2SC1708 (F, GI	1 A, 1. 2B
TR03, 04	0306360.1	2SC1951 (1.2)	1A, 2B
TR05, 06	0300470.1	2SA726W (F, G))	2 A
TR07,08	0306360.1	2SC1951 (1.21	2 A
IC01,02	0360370.1	2SA798 (F, G	1A, 1. 2B
C01, 02	0602109	1F 100V М.С.	1 A, 1. B
VR01	1090220	100k Ωx4 Detent Volume	1.2 A
S01	1190290	Tone & Filter Switch	1. 2 A

3-3. F-2691 Equalizer Circuit Board

This board implements the equalizer (phono preamplifier) stage.

Parts No.	Stock No.	Description	Position
TR01,02	0306070.1	2SC1313 (F. G)	1 B, C
TR03,04	0306270.1	2SC1708 (F,G)	1 B,2B
TR05,06	0306270.1	2SC1708 (F,G) Transistor	1B,2B
TR07,08	0300710.1	2SA847 (F. G)	1 B,2B
TR09, 10	0306270.1	2SC1708 (F,G)	1B,2B
IC01,02	0360370,1	2SA798 (F, G Transistor	1C,2C
D01, 02	0311160	Diode	1C,2C
D01, 02	0311180	152473D	1C,2C
C03,04	0602229	2.2µF 100WV M.C.	1D,2D
C19, 20	0625562	5600pF	1 B,2B
C21, 22	0620101	100pF 50V P.C.	1B,2B
C23, 24	0625122	1200pF	1 B, 2 B
C25, 26	0620391	390pF 50V P.C.	1A,2A
R15, 16	0231332	3.3kΩ
R31, 32	0231223	2kΩ W M.R.
R33, 34	0231564	560kΩ
R51,52	0231102	1kΩ
2410590	4P Pin Ass'y (Type D)
2410600	6P Pin Ass'y (Type D)
2410910	2P Pin Ass'y (Type E)

3-4. F-2573 Filter Accessory Circuit Board

This board contains filter circuits.

Parts No.	Stock No.	Description	Position
TR01,02	0306270,1	2SC1708 (F, G)	2 B
TR03, 04	0300760,1	2SA917 (1.2)	2 B
C15, 16	0620821	820pF 50V P.C.
VR01	1015170,1	250kΩ (M.N) Balance Volume	1 A
S01	1190250	Mode Switch	1.2 A
S02	1170770	Muting Switch
S03	1170950	Low Filter Switch	1 C
S04	1170950	High Filter Switch	1 C
2410590	4P Pin Ass'y (Type D)
2410920	3P Pin Ass'y (Type E)

3-5. F-2577 Treble Tone Selector Circuit Board

This board handles treble tone selection.

Parts No.	Stock No.	Description
C01,02	0620331	330 pF 50V P.C.
C03, 04	0620911	910 pF
S01	1131150	Treble Tone Push Switch

3-6. F-2578 Bass Tone Selector Circuit Board

This board handles bass tone selection.

Parts No.	Stock No.	Description
S01	1131140	Bass Tone Push Switch

3-7. F-2571 Tape Copy & Tuner Signal Switching Circuit Board

This board manages tape copy and tuner signal switching.

Parts No.	Stock No.	Description
S01	1170870	Lever Switch, tuner
S02	1190280	Tape Copy Switch

3-8. F-2572 Tape Play Circuit Board

This board is for tape playback functions.

Parts No.	Stock No.	Description
S01	1190270	Tape Play switch
2410760	6P Pin Ass'y (Type C)
2410780	6P Pin Ass'y (Type C)

3-9. F-2575 Midrange Tone Control Circuit Board

This board controls midrange tone.

Parts No.	Stock No.	Description	Position
TR01,02	0306270.1	2SC1708 (F. G) Transistor	2A,2B
IC01,02	0360290,1	2SA798 (F,G) IC	2A,2B
VR01	1090150.1	50kΩ (B) 2 Midrange Volume	1 B
2410700	6P Pin Ass'y (Type F)

3-10. F-2579 Pre-Main Switch Circuit Board

This board contains the pre-main switch logic.

Parts No.	Stock No.	Description
RL01	1150320	Relay Switch
2430260	Female Pin Jack (White)
2430270	Female Pin Jack (Red)
S01	1110320	PRE Main Switch

3-11. F-2576 Bass & Treble Tone Control Circuit Board

This board handles bass and treble tone control.

Parts No.	Stock No.	Description	Position
TR01,02	0306270,1	2SC1708 (F. G) Transistor	2C,2A
IC01,02	0360290,1	2SA798 (F. G) IC	2C,2A
C01,02	0620301	300pF 50V P.C.	1 C
VR01	1090150.1	50kΩ (B) 2 Treble Volume	1 A
VR02	1090150.1	50kΩ (B) 2 Bass Volume	1 C
2410680	4P Pin Ass'y (Type F)

3-12. F-2581 Final Stage Circuit Board

This board contains the final output stage components.

Parts No.	Stock No.	Description	Position
TR01	0306451.2	2SC1403A (O, Y)
TR02	0306451,2	2SC1403A (O, Y)
TR01	0300831,2	2SA745A (O. Y)	Transistor
TR02	0300831,2	2SA745A (O. Y)	Transistor
R01,02	0192829	8.2Ω W F.R.
R03, 04	0135338	0.33Ω 5 W Ce.R.
2030040	Transistor Socket
2030040	Transistor Socket
2410910	2P Pin Ass'y Type E

3-13. F-2661 Driver Circuit Board

This board serves as the driver stage for the power amplifier.

Parts No.	Stock No.	Description	Position
TR01, 02	0300760,1	2SA917 (1,2)	1A,1C
TR03, 04	0306290,1	2SC1400 (1) U, E	1A,1C
TR05,06	0306290.1	2SC1400 (1) U. E	1A,1C
TR07,08	0300770.1	2SA896-1 (1,2)	2A.1B
TR09, 10	0306260.1	2SC1628 Ο. Υ	2 A. 1.2C
TR11, 12	0306350.1	2SC1811-1 (1,2)	2A.2B
TR13, 14	0306401,2	2SC1904 B. V	3A.3B
TR15, 16	0305640.1	2SC735 O, Y	2A.2C
TR17, 18	0300220,1	2SA562 Ο. Υ	2A.2C
TR19, 20	0306350.1	2SC1811-1 (1.2)	2A.2C
TR21, 22	0300700.1	2SA818 Ο. Υ	2A.2B
TR23, 24	0308441,2	2SD382 (M,L)	3A.3C
TR25, 26	0303271,2	2SB537 (M.L.) Transistor	3A.3B
IC01,02	0360370,1	2SA798 (F. G) IC	1A.1C
D01, 02	0340120	VD1212 Varistor	1A.1C
D03, 04	0340120	VD1212	1A. 18, C
D05, 06	0311160	1S2473D	2A.2C
D07, 08	0311180	151588	Diode	2A.2B
D09, 10	0311160	1S2473D	2A.2C
D11, 12	0311180	151588	Diode	2A.2B
C13, 14	0602108	0.1µF 100WV M.C.	1A.1B
C41, 42	0602108	0.1µF 100V M.C.	3B.3C
C43, 44	0602108	0.1µF	3A.3B
C45, 46	0669002	3.9pF 50V C.C.	2A.2B
C47, 48	0549301	470µF 80V E.C.	1, 2B. 2 C
C49, 50	0549301	470µF	2B.2C
C51, 52	0602108	0.1µF 100WV M.С.	1B.1C
C53, 54	0602108	0.1µF	2B.2C
R51, 52	0191471	470Ω	2B.2C
R53, 54	0191471	470Ω W F.R.	2A.2B
R59, 60	0192680	68Ω	2A.2C
R61, 62	0192680	68Ω W F.R.	2 A. 2B, C
R63, 64	0192680	68Ω	2. 3B. 2 C
R65, 66	0192680	68Ω	2. 3B. 2 C
R75, 76	0203100	10Ω 3 W N.I.R.	2A.2C
VR01,02	1035050	470Ω Β	1A.1B
2410590	4P Pin Ass'y TYPE D
2410680	4P Pin Ass'y TYPE F
2410920	3P Pin Ass'y TYPE E

3-14. F-2629 Power Supply Circuit Board

This board is the main power supply unit.

Parts No.	Stock No.	Description	Position
D01	0311310	Diode	1 C
D01	0311540	SS-5	1 A
D02	0311310	Diode	1 C
D02	0311540	SS-5	1 A
D03	0311320	Diode	1 A
D03	0311550	SS-5R
D04	0311320	Diode	1 C
D04	0311550	SS-5R
C01,02	0602109	1µF 100WV M.С.	2 A, 2 C
C03, 04	0602109	1µF	2 A, 2 C
C05,06	0605477	0.047µF 250V M.C.	1A,1C
R01,02	0202332	3.3kΩ 2 W N.I.R.	1A,1C
R03,04	0202332	3.3kΩ 2 W N.I.R.	1A,1C
F01-04	0432500	AC Fuse 7A 125V	1.2 B

3-15. F-2630 Power Supply Circuit Board for Driver Stage

This board provides power to the driver stage.

Parts No.	Stock No.	Description	Position
TR601	0300721.2	2SA850 (D. E)	1 A, B
TR602	0306281.2	2SC1735 (D. E)	1A, B
TR603	0300720,1	2SA850 (C, D)	1A, B
TR604	0306280.1	2SC1735 (C, D)	1A. B
TR605	0308441.2	2SD382 (L, M)	1 B
TR606	0303271,2	2SB537 (L, M)	1 B
TR607	0308450.1	2SD356 (C. D)	1 B
TR608	0308611.2	2SD357 (D. E)	1 B
TR609	0303441.2	2SB527 (D. E)	1 B
TR610	0303280,1	2SB526 (C. D)	1 B
TR611	0306281.2	2SC1735 (D. E)	2 C
TR612	0300720.1	2SA850 (C. D)	1 B
TR613	0306290,1	2SC1400 (E. U)	1 B
TR614	0306290.1	2SC1400 (E. U)	2 C
TR615	0300470.1	2SA726W (F. G)	1 B
TR616	0300470,1	2SA726 (F. G)	1 B
TR617	0300511.2	2SA733 (Q.R)	2.3 C
TR618	0306131.2	2SC1364 (6.7)	2.3 C
TR619	0306131.2	2SC1364 (6.7)	2 C
TR620	0306131.2	2SC1364 (6.7)	2 C
D01,02	0311160	1S2473D	1 C
D01,02	0311180	151588	Diode	1 C
D603	0310350	10D2	2 A
D604	0310350	10D2	2 A
D605	0310340	10D1	3 B
D606	0310340	10D1	3 B
D607	0340120	VD1212	1 A
D608	0340120	VD1212	1 A
D609	0310490	SV-02	3C
D610	0311160	1S2473D	3C
D611	0311180	151588	Diode	2 C
D612	0311160	1S2473D	2 C
D613	0311180	151588	Diode	2 D
D614	0311160	1S2473D	1 D
D615	0311180	151588	Diode	2 D
D616	0311160	1S2473D
D617-619	0310340	10D1	1 D
C601	0549301	470µF 80V E.C.	1 A
C602	0549301	470µF	1.2 A
C611,612	0655472	4700 pF
C628	0655103	10000 pF 500V C.C.
C629	0655472	4700 pF	2 A
R01,02	0104479	4.7Ω 1 W C.R.	2C,2D
R03, 04	0203100	10Ω 3W N.I.R.	3 C
R09, 10	0135221	220Ω 5W Ce.R.	1A,2A
R603-606	0191471	470Ω 4W F.R.
R607,608	0202151	150Ω 2 W N.I.R.
R619-622	0191100	100Ω W F.R.	1 B
R644	0211471	470Ω 1 W N.I.R.	2C. D
R646	0202151	150Ω 2 W N.I.R.
R647	0183471	470Ω 3 W Ce.R.	2 C
R651	0211391	390Ω 1 W N.I.R.	3 C
L01,02	4210290	Filter Coil 1.5H	2 D
RL01	1150370	Relay	2 D
RL02	1150360	Relay	1 D
F601,604	0432240	2A 250V A.C. Fuse	3A, B

[Circuit diagram for the AU-9900A Power Supply Section, EU. BS MODEL ONLY]

[Circuit diagram for the AU-11000A Power Supply Section, EU. BS MODEL ONLY]

4. Other Parts

4-1. Top & Bottom View

These views show the internal component layout from the top and bottom of the amplifier chassis, identifying major boards and components like the Power Transformer (PT), Power Cord, Voltage Selector, and various circuit boards (F-2569, F-2661, F-2630, etc.).

[Top view of the amplifier chassis showing internal component placement]

[Bottom view of the amplifier chassis showing internal component placement]

4-2. Exploded View

This exploded view provides a visual breakdown of the amplifier's physical components, allowing for identification and location of parts for assembly and disassembly.

Parts No.	Stock No.	Description	Parts No.	Stock No.	Description
2	5006660	Bonnet (Al	30	6906480	Spling, Push Knob
3	5006521	Bonnet (B)	31	5326531	Push Knob
4	5288640	Output Terminal Base	32	1101700,1	Rotary Switch, Speakers Switch
5	5304081	Side Bonnet L-CH	33	1090150.1	50kΩ x 2, Trable Volume
6	5304091	Side Bonnet R-CH	34	1170510	Lever Switch, Power
7	5287411	Input Terminel Base	35	5047470	Masking, Lever Switch
9	7726140	LED Ass'y. Protector Indicator	36	2430190	Headphone Jack
10	5318262	C-6 Type Knob. Speaker Switch	37	1090150,1	50kΩ x 2, Midrange Volume
11	5318253	B-6 Type Knob. Treble Volume	38	1090150.1	50kΩ x 2, Bass Volume
12	5326510	E-2 Type Knob. Power Switch	39	1131150	Push Switch, Tone Selector (Treble)
13	5318253	B-6 Type Knob. Midrange Volume	40	1131140	Push Switch, Tone Selector (Bass)
14	5318253	B-6 Type Knob, Bass Volume	41	1190290	Tone & Filter Switch
15	5318262	C-6 Type Knob. Tone & Filter Switch	42	1170950	Low Filter Switch
16	5326520	E-3 Type Knob. Filter & Muting Switch	43	1170950	High Filter Switch
17	5318800	G-7 Type Knob. Volume	44	1170770	Lever Switch. Muting
19	5318271	D-6 Type Knob. Balance Bolume	45	5047821	Masking, Lever Switch
20	5318371	H-6 Type Knob, Tape Play Switch	46	1090220	100kΩ x 4. Volume
21	5318281	F-6 Type Knob. Mode Switch	47	1015170,1	250kΩ, Balance Volume
22	5318371	H-6 Type Knob, Input Selector	48	1190270	Tape Play Switch
23	5318281	F-6 Type Knob, Tape Copy Switch	49	1190250	Mode Switch
24	5326510	E-2 Type Knob. Tuner Switch	50	1190260	Input Selector
25	5286731	Lever Guide (1)	51	1190280	Tape Copy Switch
26	5286721	Knob Guide	52	1170870	Lever Switch, Tuner
27	5286741	Lever Guide (2)	54	5517050	Leg
28	5336581	Sansui Mark	56	5058492	Bottom Plate
29	7007482	Panel Ass'y (AU-9900A)
	7007472	Panel Ass'y (AU-11000A)

[Exploded view of the Sansui AU-9900A/11000A amplifier showing all external and internal parts]

5. Adjustments

5-1. Bias Current Adjustment

This procedure details how to adjust the bias current for optimal performance and protection against thermal issues. It requires specific conditions and measurements using an oscilloscope, distortion meter, VTVM, or a DC Milliammeter.

Conditions:

Room Temperature: 18°C~28°C (65°F~83°F)
Output Load (Speaker): 8 ohms
A.C. Supply Voltage: Rated Voltage ±2%
Turn down the volumes, VR01, VR02 on F-2661 till minimum (counterclockwise).
Level Volume: Maximum
Unit must be run for more than 3 minutes after turning on the power switch for adjustment.

Steps:

Distortion factors & Switching distortion adjustment: At 50kHz, set the amplifier output to 15V on both channels by adjusting the O.S.C. output level. Use the oscilloscope and distortion meter to find the minimum point of distortion factors and switching distortion. Adjust VR01 (L-CH) and VR02 (R-CH) on F-2661.
Bias Current confirmation (no input signal): Confirm the bias current to be within 50mA. Adjust VR01 (L-CH) and VR02 (R-CH) on F-2661.

Note: After Step 1, allow a 5-10 minute cooling-off period before confirming bias current. If a distortion meter is unavailable, complete adjustment by Step 2 to achieve 50mA bias current. Complete adjustments quickly to avoid temperature rise.

[Diagram showing connections for bias current adjustment using a milliammeter]

[Diagram showing front panel controls (VR01, VR02) on F-2661 for bias adjustment]

6. Schematic Diagram

This section provides detailed schematic diagrams for various sections of the AU-9900A/11000A amplifier. These diagrams illustrate the electronic circuit designs and component interconnections.

6-1. AU-9900A/11000A Pre AMP. Section Schematic Diagram

This diagram details the circuit layout for the pre-amplifier stage, including input selection, tone controls, and filtering.

[Schematic diagram for the Pre-Amplifier section]

6-2. AU-9900A Power AMP. Section Schematic Diagram

This diagram illustrates the circuit design for the AU-9900A's power amplifier stage.

[Schematic diagram for the AU-9900A Power Amplifier section]

6-3. AU-11000A Power AMP. Section Schematic Diagram

This diagram illustrates the circuit design for the AU-11000A's power amplifier stage.

[Schematic diagram for the AU-11000A Power Amplifier section]

6-4. AU-9900A Power Supply Section Schematic Diagram

This diagram shows the power supply circuitry for the AU-9900A model, including fuse and voltage regulation.

[Schematic diagram for the AU-9900A Power Supply section (EU. BS MODEL ONLY)]

6-5. AU-11000A Power Supply Section Schematic Diagram

This diagram shows the power supply circuitry for the AU-11000A model, including fuse and voltage regulation.

[Schematic diagram for the AU-11000A Power Supply section (EU. BS MODEL ONLY)]

7. Packing List

This section would typically list items included with the product, such as accessories or documentation. (Content not detailed in provided OCR).

8. Accessory Parts List

This section lists available accessory parts for the amplifier. (Content not detailed in provided OCR).

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