Marantz 1180DC Manual

The Marantz 1180DC is a high-performance stereo receiver featuring Dolby noise reduction, DC power amplifier circuitry, 80 watts per channel RMS power output, multiple audio inputs/outputs, phono input for turntables, tape monitoring, loudness compensation, and advanced tone controls. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: DC power amplifier, Dolby noise reduction system, multiple input/output terminals, precision tone controls, and advanced protection circuitry.

Feature	Description
Power Output	80 watts per channel RMS (8 ohms)
Dolby NR	Built-in Dolby B noise reduction for tape decks
Inputs	Phono, Tuner, Aux, Tape 1, Tape 2
Outputs	Speaker A/B, Headphone, Tape Rec
Tone Controls	Bass, Treble, Midrange with turnover controls
Loudness	Loudness compensation switch
Protection	DC protection circuit, thermal protection
Power Requirements	120V AC, 60Hz
Dimensions	Standard component width (17-inch)
Weight	Approximately 25 lbs

Installation

Unpack and inspect contents. Place on stable, well-ventilated surface.

1. Connect speakers: Use speaker terminals for A/B speaker systems.
2. Connect audio sources: Use appropriate inputs (Phono, Tuner, Aux, Tape).
3. Connect tape decks: Use Tape 1/Tape 2 inputs and outputs for recording.
4. Plug into AC power outlet.
5. Connect antenna to tuner input for radio reception.

WARNING! Ensure proper ventilation; do not block cooling vents. Use correct speaker impedance.

First-Time Setup

Power on receiver; follow initial setup procedure.

1. Speaker selection: Choose A/B speakers using front panel switches.
2. Input selection: Rotate input selector to desired source.
3. Volume control: Set to minimum before power on.
4. Tone controls: Set to flat position for initial listening.
5. Loudness: Engage for low-volume listening if desired.

CAUTION! Always turn volume to minimum before powering on to prevent speaker damage.

Specifications

• Power Output: 80 watts per channel RMS at 8 ohms
• Frequency Response: 10Hz - 50kHz (+0, -1dB)
• Total Harmonic Distortion: 0.02% at rated power
• Input Sensitivity: Phono: 2.5mV, Aux/Tape: 150mV
• Signal-to-Noise Ratio: Phono: 76dB, Aux: 90dB
• Tone Controls: Bass ±10dB at 100Hz, Treble ±10dB at 10kHz
• Damping Factor: 60 at 8 ohms
• Power Consumption: 280 watts maximum
• Dimensions: 17" W × 5.5" H × 14" D

Controls and Settings

Front Panel: Power switch, Input selector, Volume, Balance, Tone controls, Loudness, Speaker selectors, Tape monitor, Dolby NR.

Rear Panel: AC power cord, Speaker terminals, Input/output jacks, Antenna terminals, Phono ground.

Tone Controls: Bass, Treble with turnover frequency selection. Filter: High and low filters for noise reduction. Mode: Stereo/Mono selection. Meters: Power output level indicators. Protection: Automatic DC protection circuit.

Connecting Devices

Speakers: Use A/B terminals. Audio Sources: Phono for turntables, Aux for CD players, Tuner for radio. Tape Decks: Tape 1/Tape 2 inputs/outputs.

1. Turn off power before making connections.
2. Match cable types to inputs (RCA for line level, special cables for phono).
3. Connect phono ground wire to reduce hum.
4. Use proper speaker wire gauge for distance.

Tip: Keep signal cables away from power cords to prevent hum.

Operation Guide

Basic operation procedures for optimal performance.

1. Power on: Switch power on, wait for protection circuit to engage.
2. Source selection: Rotate input selector to desired source.
3. Volume adjustment: Increase volume gradually to desired level.
4. Tone adjustment: Use tone controls to suit listening preference.
5. Tape monitoring: Use tape monitor for recording/playback.
6. Dolby NR: Engage when playing Dolby-encoded tapes.
7. Speaker selection: Choose A, B, or both speaker systems.

WARNING! Do not operate with covers removed. Avoid excessive volume levels.

Audio Features

Dolby Noise Reduction: Reduces tape hiss on Dolby-encoded recordings. Loudness Compensation: Boosts bass and treble at low volumes. Tone Controls: Independent bass, midrange, and treble adjustment. Filters: High and low cut filters for noise reduction. Mono/Stereo: Switch between stereo and mono modes.

Care & Maintenance

Unplug before cleaning. Use soft, dry cloth for exterior. Clean controls with contact cleaner if needed. Keep vents clear of dust.

CAUTION! Do not use liquids or aerosols near controls. Service by qualified technician only.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits for residential use. Copyright © Marantz; all rights reserved. For technical support and service, contact authorized Marantz service centers. Manufactured to meet industry standards for audio performance and safety.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound	Protection mode/speakers	Check protection circuit; verify speaker connections; reduce volume.
Hum or noise	Grounding/cables	Connect phono ground; check cable routing; verify connections.
Distorted sound	Overload/settings	Reduce volume; check input levels; verify source quality.
One channel silent	Balance/connections	Adjust balance control; check cable connections; test source.
Protection engaged	Overload/short circuit	Check speaker wires for shorts; allow unit to cool; reduce volume.

Reset: Power cycle unit if protection engages repeatedly.

Service: Contact authorized Marantz service center for internal repairs.