SANSUI G-4700 AM/FM STEREO RECEIVER SERVICE MANUAL
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Specifications
| Audio section | |
| Power output | Min. RMS, both channels driven, from 20 to 20,000 Hz with no more than 0.05% total harmonic distortion. 50 watts per channel into 8 ohms |
| Load impedance | 8 ohms |
| Total harmonic distortion | less than 0.05% at or below rated min. RMS power output |
| Intermodulation distortion (70 Hz: 7 kHz = 4:1 SMPTE method) | less than 0.05% at or below rated min. RMS power output |
| Frequency response (at 1 watt) | Overall (from TAPE/AUX) 10 to 70,000 Hz +1.0 dB, -2.0 dB |
| RIAA curve deviation (PHONO, 30 Hz, to 15 kHz) | +0.5 dB, -0.5 dB |
| Damping factor (20 Hz to 20 kHz, both channels driven) | 30 into 8 ohms |
| Input sensitivity and impedance (at 1 kHz) | PHONO: 2.5 mV/47 kilohms (Max. Input capability: 200 mV at 1 kHz, less than 0.5% total harmonic distortion.) TAPE PLAY, TAPE/AUX: 150 mV/47 kilohms |
| Hum and noise (short-circuit, A-network) | PHONO: 76 dB TAPE PLAY, TAPE/AUX: 95 dB |
| Output level (at 1 kHz) | TAPE REC: 150 mV |
| Channel separation (at 1 kHz) | PHONO: 50 dB TAPE PLAY, TAPE/AUX: 50 dB |
| Controls | BASS: ±10 dB at 50 Hz TREBLE: ±10 dB at 10 kHz |
| SUBSONIC FILTER | -3 dB at 16 Hz (6 dB/oct) |
| LOUDNESS (VOLUME control: -30 dB position) | 9 dB at 50 Hz, 6 dB at 10 kHz |
| FM section | |
| Tuning range | 88 to 108 MHz |
| Usable sensitivity | Mono IHF: 10.8 dBf (1.9 μV) DIN: 1.2 μV Stereo IHF: 19 dBf |
| 50 dB quieting sensitivity | Mono: 15 dBf Stereo: 38 dBf |
| Signal to noise ratio (at 65 dBf) | Mono: 75 dB Stereo: 70 dB |
| Distortion (at 65 dBf) | Mono: less than 0.18% at 100 Hz, less than 0.15% at 1,000 Hz, less than 0.25% at 6,000 Hz. Stereo: less than 0.3% at 100 Hz, less than 0.25% at 1,000 Hz, less than 0.3% at 6,000 Hz. |
| Alternate channel selectivity (at 400 kHz) | 50 dB |
| Capture ratio | 1.0 dB |
| Image response ratio | 48 dB |
| Spurious response ratio | 70 dB |
| IF response ratio | 90 dB |
| Stereo separation | 30 dB at 100 Hz, 40 dB at 1,000 Hz, 28 dB at 10,000 Hz |
| Frequency response | 30 to 15,000 Hz +0.5 dB, -1.0 dB |
| Antenna input impedance | 300 ohms balanced, 75 ohms unbalanced |
| AM section | |
| Tuning range | 530 to 1,600 kHz |
| Usable sensitivity (bar antenna) | 50 dB/m (300 µV/m) |
| Selectivity | 33 dB |
| Signal to noise ratio | 46 dB |
| Distortion (at 30% Modulation, 80 dB/m) | less than 0.5% |
| Others | |
| Power requirements | For U.S.A, and Canada: 120 V (60 Hz) |
| Power voltage | 100, 120, 220, 240 V (50/60 Hz) |
| Power consumption | 160 watts 190 VA |
| Dimensions | 433 mm (17-1/16") W x 155 mm (6-1/8") H x 355 mm (14") D |
| Weight | 8.6 kg (19.0 lbs) net, 10.0 kg (22.0 lbs) packed |
| • Design and specifications subject to changes without notice for improvements. | |
A visual representation of the SANSUI G-4700 AM/FM Stereo Receiver is shown, featuring front panel controls and display.
SANSUI ELECTRIC CO., LTD. logo and name.
Block Diagrams
1. Block Diagram
The main block diagram illustrates the signal flow of the SANSUI G-4700. The AM and FM antennas connect to the Tuner Section. The Tuner Section includes IC03 (LA1240 AM Tuner IC), IC04 (BA658), MSM5540 (D/A Converter, Level Meter, Counter Driver), and IC01 (µPC1167C Quadratur Detector IC) and IC02 (µPC1161C MPX IC). The Tuner Section processes AM/FM signals, including IF OFFSET and MUTING functions, and outputs to the Amp Section. The Amp Section receives signals from PHONO, TAPE/AUX, and TAPE REC inputs. It includes EQ, S04, S03, S02, and S01 stages, along with controls for MASTER, BALANCE, and TONE. The signal then proceeds to the output stages (L-ch and R-ch).
2. Interior Block Diagram of IC
µPC1167C (Quadratur Detector IC)
This IC integrates circuits for MUTE, S Meter, Level Detection, Quadratur Detection, and AUDIO MUTE, along with various amplifier stages (1st IF AMP, 2nd IF AMP, 3rd IF AMP, AUDIO AMP).
µPC1161C (MPX IC)
This IC handles stereo decoding and multiplex functions. It includes circuits for PILOT, STEREO PHASE LOCK DETECTOR, PRESENCE DETECTOR, SWITCH, LAMP DRIVER, and stereo demodulation for L-CH and R-CH outputs.
LA-1240 (AM Tuner IC)
This IC is designed for AM tuning, incorporating RF AMP, MIX, OSC, AGC DRIVE, and SM DRIVE functionalities.
3. Adjustments
FM Adjustment
1. FM IF, RF Adjustment and Dial Calibration
This section details the procedure for adjusting the FM IF, RF circuits, and calibrating the dial. It involves connecting test equipment like a Genescope, VTVM, and Scope to specific test points (TP) and adjusting various coils (IF COIL, Discriminator Coil, RF Adj.) and potentiometers (VR03, VR01) using specified feed signals and measurement outputs. Remarks include achieving maximum output, steep linearity of S-curve, symmetrical S-curve, mini distortion, and ensuring the signal indicator lamp lights up.
2. FM STEREO Adjustment
This subsection outlines the adjustments for FM stereo reception, focusing on PLL VCO Adj. and Separation. It requires specific feed signals (e.g., 19 kHz pilot tone) and measurement outputs (e.g., L-ch REC OUT). Adjustments are made using VR02 and VR01 to achieve a center position for the lighting range and a specific output value (-40 dB) for separation confirmation.
AM IF Adjustment & Dial Calibration
This section provides steps for adjusting the AM IF Coil, Dial Calibration for 600 kHz and 1400 kHz, and AM RF adjustments. It involves using an AM SSG and connecting test equipment to specific points on the circuit boards (e.g., VC4 on FM Pack, TP15, T03, L01, TC2, TC1). The goal is to achieve maximum output and proper dial indication.
Driver Circuit Board Adjustments
This section covers adjustments for the Driver Circuit Board, including DC OV Adj. (L-ch and R-ch) and Bias Current Adj. (L-ch and R-ch). It requires a DC Volt Meter and refers to Figure 3-1 for adjustment points. The target values are 0V for DC Offset and 4.5 mV (15 mA) for Bias Current.
Figure 3-1: Bias Current Adj. Point: Illustrates the locations of transistors (TR01-TR04) and resistors (R01) on the circuit board where bias current adjustments are made using a voltmeter.
Intermediate frequency of AM Section (Figs. 3-2 & 3-3): Notes that both 450 kHz and 455 kHz IF filter types are adaptable. It provides stock numbers for IF filters and specifies the insertion positions for jumper wires and diodes when replacing components, referencing component views.
4. Threading of Dial Cord
This section provides instructions for replacing the dial cord if it is cut or slips. The unit uses a 0.5 mm cord, approximately 160 cm (65.3 inches) in length. The procedure involves threading the cord in numerical order (1 to 11) as shown in Figure 1, after opening the variable capacitor completely.
Figure 1: Dial Cord Threading: A diagram showing the path of the dial cord around pulleys and guides on the front panel mechanism of the G-4700.
Parts Lists and Circuit Board Layouts
This section details the components and their locations on various circuit boards of the SANSUI G-4700.
5-1. F-3062 AM/FM Tuner & FM MPX Circuit Board (Stock No. 7522271)
Conductor Side: Shows the layout of components on the F-3062 board, labeled A, B, C. A parts list details transistors, ICs, diodes, capacitors, resistors, and coils with their respective part numbers, stock numbers, descriptions, and positions on the board. Note: Some capacitors and resistors are omitted and should be referenced from the Common Parts List.
5-2. F-3066 Main Amp & Power Supply Circuit Board (Stock No. 7503421)
Conductor Side: Depicts the component layout on the F-3066 board, labeled A, B, C. A comprehensive parts list includes transistors, FETs, diodes, Zener diodes, capacitors, resistors, and other components with their stock numbers, descriptions, and positions.
5-3. F-3000 Digitally Display Circuit Board (Stock No. 7597971)
Conductor Side: Illustrates the component layout on the F-3000 board, labeled A, B, C, D. A parts list covers transistors, diodes, ICs, FETs, and trimmer capacitors with their stock numbers, descriptions, and positions.
5-4. F-3010 Pre Scaler Circuit Board (Stock No. 7597981)
Conductor Side: Shows the component layout on the F-3010 board, labeled A, B. A parts list includes transistors, ICs, diodes, and choke coils with their stock numbers, descriptions, and positions.
5-5. F-3063 Stereo & Quartz Lock Indicator Circuit Board
Conductor Side: Details the components on the F-3063 board. A parts list includes LEDs and a diode holder.
5-6. F-3064 Input Terminal Board
Conductor Side: Details the components on the F-3064 board. A parts list includes a 2P Input Terminal.
5-7. F-3065 Balance Volume Circuit Board
Conductor Side: Details the components on the F-3065 board. A parts list includes a 250kΩ B Balance Volume and a Push Switch.
5-8. F-3091 Voltage Regulator Circuit Board
Conductor Side: Details the components on the F-3091 board. A parts list includes transistors, diodes, Zener diodes, resistors, and a lamp.
5-9. F-2716 Voltage Selector Circuit Board
Conductor Side: Details the components on the F-2716 board. Includes a caution for fuse replacement and a diagram showing voltage selection. A parts list includes fuses and a capacitor cover.
5-10. F-3092 Power Indicator Circuit Board
Conductor Side: Details the components on the F-3092 board. A parts list includes transistors and LEDs.
Abbreviations: A list of abbreviations used in the manual for component types (e.g., C.R., E.L., Ta.C.) and their descriptions.
6. Other Parts
6-1. Front View
A diagram shows the front view of the G-4700 with numbered components. A parts list details items like the Dial Scale, Headphone Jack, Knobs, Volume controls, Balance Volume, Push Switch, Tuning Unit, Dial Pointer, and LED indicators.
6-2. Top View
A diagram shows the top view of the G-4700 with numbered components. A parts list details items like the Wood Bonnet, Leg, Power Cord, Strain Relief, AC Outlet, Power Transformer, Input Terminal, Lamp, Tension Unit, and Display Unit.
8. Packing List
| Parts No. | Stock No. | Description |
| 1 | 9116780 | Vinyl Cover |
| 2 | 9028090 | Styrofoam Packing |
| 3 | 9001941 | Carton Case |
9. Accessory Parts List
| Stock No. | Description |
| 9205040 | Operating Instructions |
| 9238230 | Schematic Diagram |
| 3820100 | FM Antenna |
Company Information
Contact information for SANSUI ELECTRONICS CORPORATION in the USA, SANSUI AUDIO EUROPE N.V. and SANSUI AUDIO EUROPE S.A. in Europe, and SANSUI ELECTRIC COMPANY LTD. in Japan.
