This document describes the Aiwa NSX-AJ70, NSX-SZ70, and NSX-SZ70E, which are compact disc stereo cassette receivers. These models are designed to provide a comprehensive audio experience, integrating multiple playback and recording functionalities.
Function Description
The devices serve as a central audio system, combining a compact disc player, a stereo cassette receiver, and an amplifier. They are equipped with an FM/AM tuner for radio reception and offer various input/output options for external audio components. The integrated amplifier drives a speaker system, providing a complete sound solution. The NSX-AJ70, NSX-SZ70, and NSX-SZ70E models cater to different regions, indicated by suffixes like U (for NSX-AJ70), HR, HS (for NSX-SZ70), and HA (for NSX-SZ70E), which may imply variations in power requirements and specific features tailored to those markets.
Important Technical Specifications
FM Tuner Section:
- Tuning Range: 87.5 MHz to 108 MHz
- Usable Sensitivity (IHF): 13.2 dBf
- Antenna Terminals: 75 ohms (unbalanced)
AM Tuner Section:
- Tuning Range: 530 kHz to 1710 kHz (10 kHz step) or 531 kHz to 1602 kHz (9 kHz step)
- Usable Sensitivity: 350 uV/m
- Antenna: Loop antenna
Amplifier Section:
- Mid-high frequency amplifier (HA, HR, HS models):
- Power Output (Rated): 32 W + 32 W (8 ohms, T.H.D. 1%, 1 kHz)
- Power Output (Reference): 40 W + 40 W (8 ohms, T.H.D. 10%, 1 kHz)
- Total Harmonic Distortion: 0.1% (15 W, 1 kHz, 8 ohms, DIN AUDIO)
- Mid-high frequency amplifier (U model):
- Power Output: 25 W + 25 W (200 Hz-20 kHz, THD less than 1%, 8 ohms)
- Total Harmonic Distortion: 0.1% (10 W, 1 kHz, 8 ohms, DIN AUDIO)
- Low frequency amplifier (HA, HR, HS models):
- Power Output (Rated): 96 W + 96 W (6 ohms, T.H.D. 1%, 135 Hz for HA; 6 ohms, T.H.D. 1%, 130 Hz for HR, HS)
- Power Output (Reference): 120 W + 120 W (6 ohms, T.H.D. 10%, 135 Hz for HA; 6 ohms, T.H.D. 10%, 130 Hz for HR, HS)
- Total Harmonic Distortion: 0.1% (45 W, 135 Hz, 6 ohms, DIN AUDIO for HA; 45 W, 130 Hz, 6 ohms, DIN AUDIO for HR, HS)
- Low frequency amplifier (U model):
- Power Output: 75 W + 75 W (50 Hz -200 Hz, THD less than 1%, 6 ohms)
- Total Harmonic Distortion: 0.1% (35 W, 135 Hz, 6 ohms, DIN AUDIO)
- Inputs:
- VIDEO/AUX: 316 mV (adjustable)
- MD: 316 mV (adjustable)
- MIC: 1.8 mV (10 kohms) for U, HA models; 1.0 mV (10 kohms) for HR, HS models
- Outputs:
- SPEAKERS HIGH FREQ: accepts speakers of 8 ohms or more
- SPEAKERS LOW FREQ: accepts speakers of 6 ohms or more
- SURROUND SPEAKERS: accepts speakers of 8 to 16 ohms
- LINE OUT: 210 mV
- PHONES (stereo jack): accepts headphones of 32 ohms or more
Cassette Deck Section:
- Track Format: 4 tracks, 2 channels stereo
- Frequency Response: CrO2 tape: 50 Hz – 16000 Hz; Normal tape: 50 Hz – 15000 Hz
- Recording System: AC bias
- Heads: Deck 1: Playback head x 1; Deck 2: Recording/Playback head x 1, erase head x 1
Compact Disc Player Section:
- Laser: Semiconductor laser (λ=780 nm)
- D-A Converter: 1 bit dual
- Signal-to-Noise Ratio: 85 dB (1 kHz, 0 dB)
- Harmonic Distortion: 0.05% (1 kHz, 0 dB)
- Wow and Flutter: Unmeasurable
Speaker System (SX-WNSZ70/WNAJ70):
- Speaker System: 3 way, Built-in subwoofer (magnetic shielded type)
- Speaker Units:
- Subwoofer: 160 mm (6 3/8 in.) cone type
- Full range: 100 mm (4 in.) cone type
- Super Tweeter: 20 mm (13/16 in.) ceramic type
- Impedance: 6 ohms/8 ohms
- Sensitivity: 87 dB/W/m
- Dimensions (W x H x D): 240 x 324 x 281 mm (9 1/2 x 12 3/4 x 11 1/4 in.)
- Weight: 5.0 kg (11 lbs) for U, HA models; 5.2 kg for HR, HS models
General:
- Power Requirements:
- U model: 120 V AC, 60 Hz
- HA, HR models: 120 V/220-230 V/240 V AC switchable, 50/60Hz
- HS model: 220 V AC, 50/60 Hz
- Power Consumption: 135 W for U model; 200W for HA, HR, HS models
- Power Consumption (Standby Mode):
- ECO OFF: 21W for HA model; 22 W for U model; 26 W for HR, HS models
- ECO ON or ECO AUTO: 0.9 W
- Dimensions (W x H x D): 260 x 330 x 360 mm (10 1/4 x 13 x 14 1/4 in.) for U model; 260 x 330 x 395 mm for HA, HR models
- Weight: 8.4 kg (18 lbs 8 oz.) for U model; 9.5 kg for HA, HR, HS models
Usage Features
The Aiwa NSX series offers a versatile audio experience. Users can enjoy music from compact discs, listen to radio broadcasts on both FM and AM bands, and play or record audio cassettes. The dual cassette deck allows for tape-to-tape dubbing. Multiple input options, including VIDEO/AUX and MD, enable connection to external audio sources such as televisions, VCRs, or MiniDisc players, expanding the system's utility. A microphone input is also available for karaoke or voice recording. The system supports various speaker configurations, including high-frequency, low-frequency, and surround speakers, allowing for a customized sound setup. A remote controller (RC-ZAS01) is included for convenient operation. The power requirements vary by model and region, ensuring compatibility with local electrical standards. The system also features an ECO mode for reduced power consumption in standby.
Maintenance Features
The manual provides crucial information for maintenance and repair, particularly concerning the internal components.
- Laser Safety: The device uses a laser, and strict precautions are outlined to prevent eye exposure during servicing. Technicians are advised to maintain a distance of more than 30cm from the objective lens of the optical pick-up block when confirming laser beam emission. Warnings about invisible laser radiation when open and interlocks defeated are highlighted.
- Capacitor Discharge Procedure: Before any repair work on the power supply block, a forced discharge procedure for electrolytic capacitors (C101, C102) is mandatory to prevent secondary defects. This involves removing the AC power cord and using a discharging resistor to reduce voltage across the capacitors to 1V or less.
- Microcomputer Checks: Detailed steps are provided for checking the microcomputer before replacement. This includes verifying the HOLD terminal's voltage level and performing a forced-reset procedure if the microcomputer is not functioning correctly despite re-insertion or software reset. The forced-reset involves shorting the electrolytic capacitor C113 connected to the VDD of the microcomputer with tweezers after removing the AC power cord, then reconnecting the power.
- Optical Block Replacement: Specific precautions are given for replacing the optical block (KSS-213F), emphasizing the need to ground the body and workbench to prevent electrostatic discharge from damaging the laser diode. After connection, a solder point must be removed.
- Parts List: A comprehensive electrical main parts list is included, detailing reference numbers, part numbers, Kanri numbers, and descriptions for various components like ICs, transistors, diodes, capacitors, coils, switches, and connectors. This list is essential for identifying and ordering correct replacement parts.
- Revision Publishing: This service manual is a "Revision Publishing," indicating that it replaces previous "Simple Manuals" for the NSX-AJ70, NSX-SZ70/SZ70E<HR, HA>, and NSX-SZ70 models, ensuring that technicians have the most up-to-date repair information.
- CD Mechanism Information: For detailed information on the CD mechanism (AZG-1), technicians are directed to a separate Service Manual of AZG-1.
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