marantz sr 66u manual

The Marantz SR 66U is a high-performance stereo receiver featuring AM/FM tuner, phono input, tape monitor, loudness control, and advanced audio circuitry. With 50 watts per channel RMS power output, gold-plated connectors, and walnut veneer cabinet, this receiver delivers exceptional sound quality for audiophiles. Below are key sections for operation, features, connections, specifications, and maintenance.

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

Features at a Glance

Key components: Stereo amplifier, AM/FM tuner, Phono input, Tape monitor, Loudness control, Speaker outputs.

Feature	Description
Power Output	50 watts per channel RMS (8 ohms)
Tuner Section	AM/FM stereo with quartz PLL synthesis
Phono Input	MM cartridge compatible
Tape Monitor	Dual tape decks capability
Loudness Control	Compensates for low volume listening
Tone Controls	Bass and treble adjustment
Input Selector	Phono, Tuner, Aux, Tape 1, Tape 2
Speaker Selector	A/B speaker switching
Headphone Jack	Front panel 1/4" stereo jack
Power Switch	Main power and speaker protection

Installation

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

Connect speakers: Use speaker wire to connect to A/B speaker terminals.
Connect turntable: Use phono input for magnetic cartridges.
Connect tape decks: Use tape 1/2 inputs and outputs.
Connect antenna: AM loop and FM dipole antennas included.
Plug into AC power outlet.

WARNING! Ensure proper ventilation; do not block heat sinks. Use correct speaker impedance.

First-Time Setup

Power on receiver; set initial controls to neutral positions.

Set input selector to desired source (Phono, Tuner, Aux).
Adjust volume to minimum before powering on.
Set tone controls to flat position (12 o'clock).
Tune FM stations using tuning knob and signal meter.
Adjust balance control for centered soundstage.

CAUTION! Always turn volume down before switching inputs or powering off.

Specifications

Power Output: 50W + 50W RMS (8 ohms, 20Hz-20kHz)
Total Harmonic Distortion: 0.02% (at rated power)
Frequency Response: 10Hz-50kHz (+0/-3dB)
Input Sensitivity: Phono: 2.5mV, Aux: 150mV
Signal-to-Noise Ratio: Phono: 76dB, Aux: 90dB
Tuner Section: FM sensitivity: 1.8uV, AM sensitivity: 300uV/m
Dimensions: 440mm W x 130mm H x 310mm D
Weight: 8.5 kg
Power Requirements: 120V AC, 60Hz, 250W

Controls and Settings

Front Panel: Power switch, Input selector, Volume, Balance, Bass, Treble, Loudness, Tape monitor, Speaker selector.

Rear Panel: Speaker terminals, Phono input, Aux input, Tape inputs/outputs, Antenna terminals, AC cord.

Input Selection: Phono (turntable), Tuner (built-in), Aux (CD player), Tape 1/2. Tone Controls: Bass ±10dB at 100Hz, Treble ±10dB at 10kHz. Loudness: Compensates for Fletcher-Munson curves. Speaker Selection: A, B, or A+B speakers.

Connecting Devices

Turntable: Phono input (ground wire to terminal). Tape Decks: Tape 1/2 inputs and outputs. CD Player: Aux input. Speakers: A/B terminals (observe polarity).

Turn off power before making connections.
Use quality shielded cables for audio connections.
Ensure proper grounding for phono input.
Match speaker impedance (4-16 ohms recommended).

Tip: Use banana plugs or spade connectors for secure speaker connections.

Tuner Operation

AM/FM stereo tuner with quartz-controlled frequency synthesis.

Select Tuner on input selector.
Extend FM dipole antenna fully.
Rotate tuning knob while watching signal meter.
Fine-tune for strongest signal and minimum distortion.
Use stereo indicator to verify FM stereo reception.
For AM, rotate receiver for best reception.

Note: FM antenna orientation affects reception quality significantly.

Audio Features

Loudness Control: Engages bass/treble boost at low volumes. Tone Controls: Independent bass and treble adjustment. Tape Monitoring: Allows recording and playback monitoring. Phono Stage: RIAA equalized for magnetic cartridges.

Care & Maintenance

Keep unit clean and dust-free. Use soft dry cloth for cleaning. Avoid liquid cleaners. Ensure proper ventilation around heat sinks.

CAUTION! Unplug before cleaning. Do not use abrasive cleaners. Keep away from moisture.

Regulatory Information

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound from speakers	Speaker selector/connections	Check speaker selector position; verify speaker connections; ensure volume up.
Hum from phono input	Grounding issue	Connect turntable ground wire; check cable shielding.
Poor FM reception	Antenna placement	Reposition FM antenna; ensure proper extension; check connections.
Distortion at high volume	Overload/clipping	Reduce volume; check source level; verify speaker impedance.
One channel silent	Balance/cable issue	Check balance control; swap cables to isolate problem.

Service: Contact authorized Marantz service center for internal repairs.