marantz 2250 manual

The Marantz 2250 is a classic stereo receiver from the 1970s featuring 50 watts per channel RMS power, high-quality amplification, FM/AM tuner with quartz PLL synthesizer tuning, multiple audio inputs, tape monitoring, loudness contour, and sophisticated tone controls. Below are key sections for features, installation, operation, specifications, and maintenance.

1. Features at a Glance 2. Installation 3. Operation 4. Specifications 5. Controls and Functions 6. Connecting Components 7. Tuner Operation 8. Maintenance 9. Technical Information 10. Troubleshooting

Features at a Glance

Key components: Power amplifier section, FM/AM tuner, Front panel controls, Speaker terminals, Multiple input/output jacks.

Feature	Description
Power Output	50 watts per channel RMS (8 ohms)
Tuner Section	FM/AM with quartz PLL synthesizer
Inputs	Phono, Aux, Tape 1, Tape 2
Speaker Terminals	Main and Remote speaker outputs
Tone Controls	Bass, Treble, Midrange with turnover switches
Loudness Contour	Compensates for low volume listening
Filter Switches	High and Low filters
Muting	FM muting for weak signal rejection
Headphone Jack	Front panel 1/4" stereo jack
Power Switch	Main power on/off with indicator light

Installation

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

Connect speakers: Use speaker terminals for Main and Remote speakers, observing proper polarity.
Connect audio sources: Phono for turntable, Aux for CD player, Tape for tape decks.
Connect antenna: FM 300-ohm terminals for dipole antenna, AM terminal for AM antenna.
Plug into AC power outlet.

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

Operation

Power on receiver; allow 30 seconds for warm-up.

Select input source: Choose Phono, Aux, Tape 1, Tape 2, or Tuner.
Adjust volume: Start at minimum, gradually increase to desired level.
Use tone controls: Adjust Bass, Treble, Midrange to preference.
Speaker selection: Choose Main, Remote, or both speaker systems.
Tuner operation: Select FM or AM band, tune stations manually or use memory presets.

CAUTION! Do not operate at maximum volume for extended periods to avoid damage.

Specifications

Power Output: 50 watts per channel RMS at 8 ohms
Total Harmonic Distortion: 0.1% or less at rated output
Frequency Response: 10Hz - 50kHz (+0, -1dB)
Input Sensitivity: Phono: 2.5mV, Aux: 150mV
Signal-to-Noise Ratio: Phono: 75dB, Aux: 90dB
Tuner Section: FM/AM with quartz PLL synthesizer
FM Sensitivity: 1.8μV (IHF)
Power Requirements: 120V AC, 60Hz, 280 watts
Dimensions: 18-3/4" W × 5-3/4" H × 14-1/2" D
Weight: 28.5 lbs

Controls and Functions

Front Panel: Power Switch, Input Selector, Volume, Balance, Tone Controls, Filter Switches, Loudness, Speaker Selectors.

Tuner Section: FM/AM Selector, Tuning Knob, Signal Strength Meter, Stereo Indicator, FM Muting, Memory Presets.

Tone Controls: Bass (±10dB at 50Hz), Treble (±10dB at 20kHz), Midrange (±6dB at 1kHz). Filters: High Cut (8kHz, -6dB/oct), Low Cut (50Hz, -6dB/oct). Loudness: Compensates for Fletcher-Munson curves at low volumes.

Connecting Components

Speaker Connections: Main and Remote speaker terminals. Audio Inputs: Phono, Aux, Tape 1, Tape 2. Antenna Connections: FM 300-ohm, AM antenna.

Turn off power before making connections.
Connect speakers observing correct polarity (red to red, black to black).
Use shielded cables for audio connections to minimize noise.
Connect FM dipole antenna for best reception.
Select proper input source after connections complete.

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

Tuner Operation

FM/AM tuner with quartz PLL synthesizer for stable reception.

Select FM or AM band using selector switch.
Tune manually using tuning knob; observe signal strength meter.
For FM stereo, stereo indicator will illuminate when stereo broadcast detected.
Use FM muting to eliminate noise between stations.
Memory presets: Store up to 5 stations per band (consult separate memory operation section).
Fine tuning: Adjust for optimal reception on weak stations.

WARNING! Use proper antenna for best reception. Outdoor antennas may require lightning protection.

Maintenance

Keep unit clean and dust-free. Use soft, dry cloth for cleaning.

CAUTION! Unplug before cleaning. Do not use liquid cleaners or aerosols. Service by qualified technician only.

Technical Information

FCC Part 15: Class B computing device; complies with interference limits. Manufactured to Marantz quality standards. Incorporates advanced circuitry for superior audio performance. For technical service, consult authorized Marantz service centers.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound from speakers	Speaker connections/selector	Check speaker wires; verify speaker selector position; check volume setting.
Hum or noise	Grounding/cables	Check ground connections; ensure proper cable routing; verify phono ground.
Poor FM reception	Antenna/position	Check antenna connections; reposition antenna; use outdoor antenna for weak areas.
One channel dead	Balance control/cables	Check balance control; verify input cables; test with different source.
Overheating	Ventilation/impedance	Ensure adequate ventilation; check speaker impedance; reduce volume if necessary.

Service: Consult authorized Marantz service center for internal repairs.

Note: This classic equipment may require specialized service by technicians familiar with vintage audio gear.