Marantz 2285 Manual

The Marantz 2285 is a classic stereo receiver from the 1970s featuring 85 watts per channel RMS power, dual power meters, phono input for turntables, tuner section with AM/FM reception, multiple audio inputs, tone controls, loudness compensation, and speaker selector. Known for its warm sound signature and distinctive blue-lit tuning dial. 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. Troubleshooting

Features at a Glance

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

Feature	Description
Power Output	85 watts per channel RMS into 8 ohms
Tuner Section	AM/FM stereo with tuning meters
Phono Input	MM cartridge compatible with adjustable capacitance
Tone Controls	Bass, midrange, treble with defeat switch
Loudness Control	Compensates for low volume listening
Speaker Selector	A/B speaker switching
Headphone Jack	Front panel 1/4" stereo jack
Power Meters	Dual VU meters for power output display
Inputs	Phono, Aux, Tape 1, Tape 2
Outputs	Speaker terminals, tape outputs, preamp out

Installation

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

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

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

Operation

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

Select input: Choose Phono, Aux, Tape 1, Tape 2, or Tuner.
Adjust volume: Start at minimum volume when powering on.
Use tone controls: Adjust bass, midrange, treble to preference.
Tuner operation: Select AM/FM band and tune to stations.
Speaker selection: Choose A, B, or both speaker sets.

CAUTION! Avoid operating at maximum volume for extended periods to prevent damage.

Specifications

Power Output: 85 watts per channel RMS at 8 ohms
Total Harmonic Distortion: 0.15% at rated power
Frequency Response: 10Hz - 50kHz (+0, -1dB)
Input Sensitivity: Phono: 2.5mV, Aux: 250mV
Signal-to-Noise Ratio: Phono: 75dB, Aux: 90dB
Tuner Section: FM sensitivity 1.9uV, AM 30uV
Dimensions: 19-1/4" W x 6-3/4" H x 16" D
Weight: 42 lbs
Power Requirements: 120V AC, 60Hz, 450W

Controls and Functions

Front Panel: Power switch, input selector, volume, balance, tone controls, loudness, speaker selector, tuning knob, function switches.

Main Controls: Power, Volume, Balance, Bass, Midrange, Treble, Loudness, Input Selector, Speaker Selector, Tuning, Mode Selector.

Tone Controls: Bass ±10dB at 50Hz, Midrange ±6dB at 1kHz, Treble ±10dB at 15kHz. Function Switches: Mono/stereo, high filter, loudness contour, tape monitor. Tuner: Tuning meter, signal strength meter, FM muting.

Connecting Components

Speaker connections: A/B terminals. Source connections: Phono, Aux, Tape inputs. Antenna: FM 300 ohm terminals.

Turn off power before making connections.
Match cable types to appropriate inputs.
Use proper speaker wire gauge for distance.
Ensure secure connections to prevent shorts.

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

Tuner Operation

AM/FM stereo reception with tuning indicators.

Select FM or AM band using mode selector.
Rotate tuning knob until center meter indicates peak.
Use signal strength meter for best reception quality.
Engage FM muting to eliminate inter-station noise.
For stereo reception, ensure stereo indicator is lit.

WARNING! Use proper antenna for best reception; outdoor antenna recommended for weak signal areas.

Maintenance

Regular cleaning of controls with contact cleaner. Keep ventilation clear. Check connections periodically.

CAUTION! Unplug before cleaning. Do not use liquids on controls. Service by qualified technician only.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound	Speaker connections/power	Check speaker wires; verify power on; check input selection
Distorted sound	Overload/speaker impedance	Reduce volume; check speaker impedance matches requirements
Hum or noise	Grounding/cable placement	Check ground connections; separate signal and power cables
Poor FM reception	Antenna/tuning	Improve antenna connection; fine tune station
One channel dead	Balance control/cables	Check balance setting; verify source cable connections

Service: Consult qualified Marantz service technician for internal repairs.