The Marantz 2230 is a classic stereo receiver from the 1970s featuring 30 watts per channel, high-quality analog components, and the distinctive Marantz blue dial. This service manual provides comprehensive technical information for repair, maintenance, and restoration. Below are key sections covering specifications, schematics, alignment procedures, troubleshooting, and component replacement.
Key technical parameters and performance characteristics of the Marantz 2230 receiver.
| Parameter | Specification |
|---|---|
| Power Output | 30 watts per channel (8 ohms, 20Hz-20kHz) |
| Total Harmonic Distortion | 0.3% at rated output |
| Frequency Response | 10Hz-50kHz (+1/-3 dB) |
| Input Sensitivity | Phono: 2.5mV; Aux: 250mV |
| Signal-to-Noise Ratio | Phono: 70dB; Aux: 85dB |
| Tuner Section | FM/AM with multiplex stereo |
| Dimensions | 17-1/2" W × 5-1/4" H × 14-1/2" D |
| Weight | 22 lbs (10 kg) |
| Power Requirements | 120V AC, 60Hz, 180W |
| Speaker Impedance | 4-16 ohms |
Functional block diagram showing signal flow and major circuit sections.
NOTE! Understanding signal flow is essential for effective troubleshooting.
Detailed schematic diagrams for all major circuit sections.
CAUTION! Always disconnect power before working on circuits.
Step-by-step alignment instructions for optimal performance.
Physical layout of components on main chassis and circuit boards.
Main Chassis: Power transformer location, heat sinks, large capacitors
Circuit Boards: P700 (main amp), P800 (power supply), P900 (tuner)
Front Panel: Input selector, volume control, tone controls, tuning dial
Rear Panel: Speaker terminals, input jacks, antenna connections
Common problems and their solutions for the Marantz 2230.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| No sound from both channels | Power supply failure | Check fuse F801, power transformer, rectifiers |
| One channel dead | Output transistors | Test output transistors Q701-Q704; check driver stages |
| Distorted audio | Bias adjustment | Adjust bias current VR701; check capacitor C701-C704 |
| Hum in audio | Filter capacitors | Replace main filter capacitors C801, C802 |
| No FM reception | Tuner alignment | Check FM front end; align IF transformers |
| Lights but no operation | Protection circuit | Check relay RL701; test DC offset at outputs |
Complete list of components with original part numbers.
Tip: Use exact replacements or modern equivalents with same specifications.
Key voltage test points throughout the receiver.
| Test Point | Expected Voltage | Tolerance |
|---|---|---|
| Power Supply Output | +35V DC | ±2V |
| Amplifier Rails | ±42V DC | ±3V |
| Phono Preamp | +24V DC | ±1V |
| Tuner Section | +13V DC | ±0.5V |
| Protection Circuit | +24V DC | ±2V |
WARNING! High voltages present - use proper safety precautions.
Routine maintenance procedures for long-term reliability.
CAUTION! Always unplug unit before performing maintenance.
Essential safety information for working on high-voltage equipment.
This receiver contains lethal voltages even when unplugged. Large filter capacitors can hold dangerous charge for extended periods. Always discharge power supply capacitors before working. Use isolation transformer when servicing live circuits. Work in dry environment with proper tools.
Resources for additional support and replacement parts.
Marantz Professional Support: Available through authorized service centers. Online Forums: Audiokarma, DIYAudio for community support. Parts Suppliers: Mouser, Digikey for components. This service manual is provided free for educational and repair purposes.
Disclaimer: Service should be performed by qualified technicians only.