Marantz Monoblock MA500 Manual

The Marantz Monoblock MA500 is a high-performance single-channel power amplifier designed for audiophile-grade audio systems. Featuring 100 watts RMS power output at 8 ohms, 20Hz-20kHz frequency response, 0.05% THD, and 100dB signal-to-noise ratio. The amplifier includes balanced XLR and unbalanced RCA inputs, speaker output terminals, AC power input, and front panel power switch with LED indicator. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Connections 6. Connecting Audio Sources 7. Operation Guidelines 8. Protection Features 9. Care & Maintenance 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: High-current power transformer, toroidal power supply, gold-plated input connectors, heavy-duty speaker terminals, aluminum chassis.

Feature	Description
Power Output	100 watts RMS at 8 ohms, 20Hz-20kHz
Input Connectors	Balanced XLR and unbalanced RCA inputs
Speaker Terminals	Heavy-duty binding posts for secure connection
Power Supply	Toroidal transformer with high-current capability
Front Panel	Power switch with LED status indicator
Protection Circuitry	DC offset, thermal, and short-circuit protection
Frequency Response	20Hz-20kHz (±0.1dB)
THD	0.05% at rated power
Signal-to-Noise	100dB (A-weighted)
Damping Factor	200 at 8 ohms

Installation

Unpack and inspect contents. Place on stable, level surface with adequate ventilation.

Position amplifier: Allow minimum 4 inches clearance on all sides for proper ventilation.
Connect audio source: Use balanced XLR or unbalanced RCA cables from preamplifier.
Connect speakers: Use heavy-gauge speaker wire to binding posts.
Connect power: Plug into dedicated AC outlet; ensure proper voltage (120V/230V).

WARNING! Amplifier generates heat during operation; ensure adequate ventilation. Use proper lifting technique due to weight.

First-Time Setup

Power on amplifier following proper sequence.

Connect all cables before powering on.
Turn volume to minimum on preamplifier.
Power on amplifier: Switch on rear panel; LED should illuminate.
Power on source components and preamplifier.
Gradually increase volume to desired listening level.

CAUTION! Always power on amplifier last and power off first to prevent speaker damage from turn-on/off transients.

Specifications

Power Output: 100 watts RMS at 8 ohms (20Hz-20kHz)
Dynamic Power: 130 watts at 8 ohms, 200 watts at 4 ohms
THD: 0.05% at rated power
Frequency Response: 20Hz-20kHz (±0.1dB)
Input Sensitivity: 1.2V for rated output
Input Impedance: 47k ohms (RCA), 20k ohms (XLR)
Signal-to-Noise: 100dB (A-weighted)
Damping Factor: 200 at 8 ohms
Power Requirements: 120V/60Hz or 230V/50Hz
Dimensions: 17.1" W × 5.9" H × 15.7" D
Weight: 28.7 lbs (13 kg)

Controls and Connections

Rear Panel: AC power input, balanced XLR input, unbalanced RCA input, speaker output terminals, ground terminal.

Front Panel: Power switch with LED indicator (red = standby, blue = operational).

Input Selection: Automatically detects balanced/unbalanced input. Speaker Connections: Heavy-duty binding posts accept bare wire, spade lugs, or banana plugs. Power: Rocker switch with IEC power connector.

Connecting Audio Sources

Balanced XLR: For professional audio systems and long cable runs. Unbalanced RCA: For standard home audio systems.

Turn off all components before making connections.
Select appropriate input: XLR for balanced, RCA for unbalanced.
Connect speaker wires: Ensure proper polarity (+ to +, - to -).
Secure all connections firmly.

Tip: Use high-quality cables and keep signal cables away from power cords to minimize interference.

Operation Guidelines

Designed for continuous high-performance operation.

Power sequence: Always power on amplifier last, power off first.
Volume control: Use preamplifier volume control; amplifier has fixed gain.
Monitoring: LED indicates operational status; red = protection mode.
Thermal management: Ensure adequate ventilation during extended use.
Load matching: Compatible with 4-16 ohm speakers.

WARNING! Do not operate without proper load connected. Avoid shorting speaker terminals.

Protection Features

DC Offset Protection: Automatically shuts down if DC detected at output. Thermal Protection: Activates if internal temperature exceeds safe limits. Short-Circuit Protection: Protects against speaker wire shorts. Overcurrent Protection: Limits current during demanding passages.

Care & Maintenance

Unplug before cleaning. Use soft, dry cloth for exterior. Keep ventilation openings clear of dust.

CAUTION! Do not use liquid cleaners or aerosols. Internal service should be performed by qualified technician only.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits for residential use. CE compliant for European markets. Copyright © 2006 Marantz; trademarks of Marantz America, Inc. For support, visit www.marantz.com or contact 1-800-270-2744.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound output	Power/connections	Check power connection; verify input source selection; check speaker connections.
Protection mode (red LED)	Overheating/short circuit	Allow to cool; check for shorted speaker wires; ensure proper ventilation.
Hum or noise	Ground loop/cables	Check ground connections; separate signal and power cables; use balanced connections.
Intermittent operation	Loose connections	Verify all cable connections are secure; check input sources.
Distorted sound	Overload/damaged speakers	Reduce volume; check speaker impedance compatibility; inspect speakers.

Reset: Power cycle amplifier; if problem persists, consult service.

Service: 1-800-270-2744; www.marantz.com