Marantz PMD660 Service Manual

The Marantz PMD660 is a professional portable solid-state recorder featuring built-in stereo microphones, XLR inputs with phantom power, CF card storage, USB connectivity, and multiple recording formats. This service manual covers technical specifications, disassembly procedures, circuit diagrams, troubleshooting, and maintenance guidelines for qualified service technicians.

1. Technical Specifications 2. Disassembly Procedures 3. Circuit Diagrams 4. Component Layout 5. Power Supply System 6. Audio Circuit Analysis 7. Troubleshooting Guide 8. Calibration Procedures 9. Parts List 10. Safety Precautions 11. Firmware Update

Technical Specifications

Key technical parameters and performance characteristics of the Marantz PMD660 recorder.

ParameterSpecification
Recording FormatMP3, WAV (16-bit/44.1kHz)
Storage MediaCompactFlash Card (Type I/II)
Input Connectors2 XLR/TRS combo, 1/4" stereo mini
Phantom Power+48V DC
Power Supply6x AA batteries or DC 9V
Frequency Response20Hz - 20kHz
Signal-to-Noise>80dB
Dimensions180 x 105 x 55 mm
Weight650g (without batteries)
Operating Temp0°C to 40°C

Disassembly Procedures

Step-by-step instructions for safely disassembling the PMD660 unit.

  1. Remove battery cover and batteries from compartment.
  2. Unscrew 8 Phillips screws from bottom case.
  3. Carefully separate top and bottom cases using plastic tool.
  4. Disconnect ribbon cables from main board to display.
  5. Remove CF card slot assembly and main PCB.
  6. Access individual components for service.

WARNING! Always discharge capacitors before handling internal components. Use anti-static precautions.

Circuit Diagrams

Complete schematic diagrams for all major circuit sections.

Component Layout

PCB component identification and placement diagrams.

Main Board: U1 - Main DSP, U2 - Flash Memory, U3 - SDRAM, U4 - USB Controller, U5 - Audio Codec, U6 - Power Regulator.

Input Board: J1 - XLR Inputs, J2 - Mini Input, IC1 - Mic Preamp, IC2 - Phantom Power Switch.

Reference designators and component values marked on silkscreen.

Power Supply System

Detailed analysis of power distribution and regulation circuits.

  1. Battery input: 6x AA (9V) or external DC 9V
  2. Primary regulation: Switching regulator to 5V and 3.3V
  3. Analog section: Clean 5V analog supply with filtering
  4. Digital section: 3.3V digital core voltage
  5. Phantom power: +48V generated from DC-DC converter

Tip: Check voltage rails in sequence when diagnosing power issues.

Audio Circuit Analysis

Signal flow and processing path from input to storage.

  1. Microphone/Line input selection via front panel switch
  2. XLR balanced inputs with +48V phantom power capability
  3. Preamplifier stage with gain control
  4. Anti-aliasing filters before ADC
  5. 24-bit analog-to-digital conversion
  6. Digital signal processing and compression
  7. CF card writing and verification

WARNING! High voltages present in phantom power circuit. Use caution during testing.

Troubleshooting Guide

SymptomPossible CauseCorrective Action
No powerBatteries/DC inputCheck battery polarity; test DC jack; verify fuse F1
No audio recordingInput selection/micsVerify input source; check mic connections; test preamp IC
CF card errorsCard/formattingReformat card; clean contacts; replace CF socket
USB not recognizedDriver/cableUpdate drivers; test with different cable; check USB IC
Distorted audioInput levels/ADCAdjust input gain; check ADC reference voltages

Reset: Hold STOP + PLAY during power-on for factory reset.

Calibration Procedures

Factory calibration and alignment specifications.

Input Level Calibration: Apply 1kHz sine wave at -20dB; adjust trimpot for proper recording levels.

ADC Alignment: Verify proper digital codes for reference voltages.

Clock Accuracy: Measure sample rate accuracy and adjust crystal load caps if needed.

Parts List

Replacement components and part numbers.

Part NumberDescriptionQty
PMD660-MBMain Board Assembly1
PMD660-DISPLCD Display Module1
PMD660-CASEMain Enclosure1
PMD660-KNOBControl Knob Assembly1
PMD660-BATTBattery Door1

Safety Precautions

Essential safety guidelines for service personnel.

Always disconnect power before servicing. Use grounded workstations. Handle CF cards with care to avoid static damage. Follow ESD protection procedures. Replace safety-critical components with exact specifications.

CAUTION! High voltages in power supply section. Capacitors may retain charge after power removal.

Firmware Update

Procedures for updating device firmware.

  1. Download latest firmware from Marantz support site
  2. Format CF card to FAT32 file system
  3. Copy firmware file to root directory of CF card
  4. Insert card into PMD660 and power on while holding MENU
  5. Follow on-screen prompts to complete update
  6. Do not power off during firmware installation

Service: Contact Marantz Professional Support for technical assistance and replacement parts.

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