Marantz PM11S2 Service Manual

The Marantz PM11S2 is a high-end integrated amplifier featuring dual monaural construction, HDAM modules, current feedback amplification, symmetrical layout, and premium components. This service manual covers technical specifications, circuit diagrams, adjustment procedures, troubleshooting, and maintenance guidelines for qualified service technicians.

1. Technical Specifications 2. Block Diagrams 3. Circuit Description 4. Adjustment Procedures 5. Disassembly Instructions 6. PCB Layouts 7. Parts List 8. Test Points 9. Troubleshooting Guide 10. Safety Precautions 11. Schematics

Technical Specifications

Detailed technical specifications for the Marantz PM11S2 integrated amplifier.

Parameter	Specification
Power Output	100W + 100W (8Ω), 200W + 200W (4Ω)
Frequency Response	5Hz - 100kHz (+0/-3dB)
Total Harmonic Distortion	0.005% (20Hz-20kHz, 8Ω)
Input Sensitivity	200mV (LINE), 1.2mV (MC), 0.16mV (MM)
Signal-to-Noise Ratio	100dB (LINE), 74dB (MC), 87dB (MM)
Input Impedance	47kΩ (LINE), 100Ω (MC), 47kΩ (MM)
Damping Factor	200 (8Ω, 1kHz)
Power Consumption	490W (max), 65W (no signal), 0.5W (standby)
Dimensions	440 × 463 × 179mm (W×D×H)
Weight	28.5kg

Block Diagrams

System block diagrams showing signal flow and power supply distribution.

Main System Block Diagram: Shows overall signal path from inputs to outputs
Power Supply Block Diagram: Illustrates dual mono power supply configuration
Pre-amplifier Section: Detailed block diagram of preamp circuitry
Power Amplifier Section: Block diagram of final amplification stage
Control System: Microprocessor control and interface block diagram

WARNING! High voltages present - discharge power supply capacitors before servicing.

Circuit Description

Detailed circuit analysis of major sections.

Power Supply Circuit: Dual mono design with separate transformers
Input Selector Circuit: Relay-based input switching system
Phono Stage: Discrete MM/MC phono equalizer with HDAM
Volume Control: Precision resistor ladder network
Power Amplifier: Current feedback topology with HDAM modules
Protection Circuit: DC detection, thermal protection, and relay delay

CAUTION! Use only specified replacement components to maintain performance.

Adjustment Procedures

DC Offset Adjustment: Adjust VR801/VR802 for 0mV ±5mV
Bias Current Adjustment: Set VR803/VR804 for 20mA ±2mA
Phono Gain Adjustment: Calibrate MM/MC input levels
Protection Circuit Test: Verify DC protection and relay timing
Temperature Sensor Check: Confirm thermal protection operation
Power Supply Voltages: Verify ±65V, ±12V, +5V supplies
Input Selector Function: Test all input switching operations

Disassembly Instructions

Step-by-step disassembly procedure for service access.

Tools Required: Phillips screwdrivers, hex keys, anti-static equipment

Remove top cover: 8 screws on rear and sides
Remove front panel: 4 screws at top and bottom
Remove main board: Disconnect all connectors and remove mounting screws
Access power supply: Remove transformer mounting bolts
Remove heat sinks: Carefully detach after removing power transistors

Tip: Document cable positions and take photos during disassembly.

PCB Layouts

Printed circuit board layouts and component locations.

Main Amplifier Board: Component side and solder side views
Power Supply Board: Layout with high voltage sections marked
Input/Selector Board: Front end circuitry layout
Control Board: Microprocessor and display circuitry
Protection Board: Relay and protection circuit layout

WARNING! High current traces identified - observe proper soldering techniques.

Parts List

Complete component listing with manufacturer part numbers.

Reference	Description	Part Number	Value/Rating
Q701-Q704	Output Transistor	2SC6011/2SA2151	200V, 15A, 130W
C701,C702	Main Filter Capacitor	15,000μF/80V	85°C
IC701,IC702	HDAM Module	HDAM-SA2	Proprietary
F701,F702	Main Fuse	T6.3A/250V	Slow Blow
RY701,RY702	Speaker Relay	OMRON G4W	30A/250VAC

Test Points

Designated test points for service measurements.

TP1, TP2: Left/Right Channel Output for DC offset measurement
TP3, TP4: Bias current measurement points
TP5, TP6: ±65V power supply test points
TP7, TP8: ±12V regulated supply test points
TP9: +5V microprocessor supply test point
TP10, TP11: Protection circuit monitoring points

CAUTION! Use proper grounding and observe polarity when testing.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
No power	Fuse, power switch, transformer	Check F701/F702; verify primary voltage; test power switch
No sound	Protection circuit, relays	Check RY701/RY702 operation; measure DC offset; test protection IC
Distortion	Bias current, output transistors	Adjust bias current; test output devices; check driver stage
Hum/buzz	Grounding, filter capacitors	Verify ground connections; test C701/C702; check input shielding
Input selection failure	Relays, control circuit	Test input relays; check microprocessor signals; verify power to control board

Reset: Power cycle to reset protection circuits.

Service: Authorized Marantz service centers only.

Safety Precautions

Essential safety procedures for service technicians.

WARNING! Lethal voltages present - always disconnect power and discharge capacitors.

Use isolation transformer when testing live circuits
Discharge main filter capacitors before working on power supply
Use anti-static precautions when handling semiconductors
Verify proper grounding of chassis and circuits
Test with current-limited power supply when troubleshooting

Schematics

Complete circuit schematics for all sections.

Main Amplifier Schematic: Complete power amplifier circuit
Power Supply Schematic: Dual mono power supply design
Pre-amplifier Schematic: Input stages and volume control
Phono Stage Schematic: MM/MC phono equalizer circuit
Control System Schematic: Microprocessor and interface circuits
Protection Circuit Schematic: Speaker protection and thermal control

Note: Schematics are proprietary Marantz documents for authorized service use only.