Marantz 2245 Receiver Manual

The Marantz 2245 is a classic stereo receiver from the 1970s featuring 45 watts per channel, high-quality analog tuning, phono inputs for turntables, multiple audio inputs, tone controls, loudness compensation, and the distinctive Marantz blue dial display. Below are key sections for features, installation, operation, specifications, and maintenance.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Components 7. Operation Guide 8. Maintenance 9. Regulatory Information 10. Troubleshooting

Features at a Glance

Key components: Power amplifier section, preamplifier with phono stage, FM/AM tuner, front panel controls, rear input/output terminals.

Feature	Description
Power Output	45 watts per channel into 8 ohms
Tuner Section	FM stereo and AM reception
Phono Input	MM cartridge compatible with adjustable capacitance
Tone Controls	Bass and treble adjustment
Loudness Control	Compensates for low volume listening
Headphone Jack	Front panel 1/4" stereo headphone output
Input Selector	Phono, Aux, Tuner, Tape Monitor
Speaker Selector	A/B speaker switching
Power Meter	VU-style power output indicators
Wood Cabinet	Optional wood enclosure

Installation

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

Connect speakers: Use speaker wire to connect to A and/or B speaker terminals.
Connect turntable: Use phono input for magnetic cartridge turntables.
Connect other sources: Use Aux input for CD players, tape decks, etc.
Connect antenna: FM antenna to 300 ohm terminals, AM antenna to AM terminal.
Plug into AC power outlet.

WARNING! Ensure proper ventilation; do not block ventilation openings. Use correct speaker impedance (8 ohms minimum).

First-Time Setup

Power on receiver; allow warm-up time for optimal performance.

Set input selector to desired source (Phono, Aux, Tuner).
Adjust volume to minimum before playing audio.
Tune FM/AM: Use tuning dial and signal strength meter for best reception.
Set tone controls to flat position initially.
Test speaker outputs with both A and B selector positions.

CAUTION! Always turn volume to minimum when switching sources or powering on.

Specifications

Power Output: 45 watts per channel (8 ohms, 20Hz-20kHz)
Total Harmonic Distortion: 0.3% at rated power
Frequency Response: 10Hz-50kHz (+0, -3dB)
Input Sensitivity: Phono: 2.5mV, Aux: 250mV
Signal-to-Noise Ratio: Phono: 70dB, Aux: 85dB
Tone Controls: Bass: ±10dB at 50Hz, Treble: ±10dB at 15kHz
FM Sensitivity: 2.0μV (IHF)
Power Requirements: 120V AC, 60Hz, 280 watts max
Dimensions: 17-3/8" W × 5-7/8" H × 14-3/4" D
Weight: 24.2 lbs

Controls and Settings

Front Panel: Power switch, input selector, volume, balance, bass, treble, loudness, speaker selector, tuning dial, function switches.

Rear Panel: Speaker terminals, phono/aux inputs, tape monitor loops, antenna connections, AC power cord.

Input Selection: Phono (turntable), Aux (CD/tuner/tape), Tuner (internal tuner). Tone Controls: Bass and treble adjustment with center detent. Loudness: Compensates for Fletcher-Munson curve at low volumes. Speaker Selector: A, B, or A+B speaker outputs. Balance: Adjusts left/right channel balance.

Connecting Components

Speaker Connections: Use 16-gauge or larger speaker wire. Phono Connection: Ground wire from turntable to ground terminal. Auxiliary Inputs: For CD players, streaming devices, tape decks.

Turn off receiver before making connections.
Connect turntable ground wire to prevent hum.
Use high-quality interconnects for best performance.
Ensure proper polarity on speaker connections.
Connect FM antenna for optimal reception.

Tip: Keep signal cables away from power cords to minimize interference.

Operation Guide

Daily operation procedures for optimal performance.

Power On: Switch power button; allow 30-second warm-up.
Source Selection: Rotate input selector to desired source.
Volume Control: Start at minimum, increase gradually.
Tuning: Use tuning dial and signal meter for FM stations.
Tone Adjustment: Adjust bass/treble to personal preference.
Loudness: Engage for low-volume listening enhancement.
Speaker Selection: Choose A, B, or both speaker sets.
Headphone Use: Plug into front panel jack; speakers mute automatically.

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

Maintenance

Regular maintenance ensures long-term reliability.

Cleaning: Use soft, dry cloth for exterior. Avoid chemicals.
Ventilation: Keep vents clear of obstructions.
Connections: Periodically check and clean terminals.
Dust Removal: Use compressed air for internal cleaning (qualified personnel only).
Lamp Replacement: Professional service required for dial lamps.

CAUTION! Unplug unit before cleaning. Internal service by qualified technicians only.

Regulatory Information

FCC Part 15: Class B computing device compliance. UL listed for safety. Manufactured to meet industry standards for audio equipment. Copyright © 1970s Marantz Company. For historical reference and collector information. Vintage electronics may require service for optimal performance.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound from speakers	Speaker selector, volume control	Check speaker selector position; ensure volume turned up; verify speaker connections.
Hum from speakers	Ground connection, source equipment	Check turntable ground wire; separate audio and power cables; try different outlet.
Poor FM reception	Antenna, location	Improve FM antenna placement; rotate antenna for best signal; check connections.
One channel not working	Balance control, cables	Check balance control position; swap L/R cables to isolate issue; clean controls.
Distorted sound	Overload, speaker impedance	Reduce volume; check speaker impedance (8 ohms minimum); verify source level.
Lights not working	Bulb failure, power	Professional service required for dial lamp replacement; check power connection.

Service: Consult qualified vintage audio technician for repairs. Original schematics available from Marantz archives.