marantz model 2270 manual

The Marantz Model 2270 is a classic stereo receiver from the 1970s featuring 70 watts per channel RMS power, high and low filters, loudness contour, tape monitor circuits, and exceptional build quality. Known for its distinctive blue-lit tuning dial and wood cabinet, this receiver delivers warm, rich sound reproduction. Below are key sections covering specifications, operation, connections, maintenance, and troubleshooting.

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 controls, tuning section, input/output terminals, and protection circuitry.

Feature	Description
Power Output	70 watts per channel RMS (8 ohms)
Tuning Section	FM/AM tuner with signal strength meter
Input Selector	Phono, Aux, Tape 1, Tape 2
Filters	High and low frequency filters
Loudness Control	Compensates for low volume listening
Tape Monitor	Dual tape monitor circuits
Headphone Jack	Front panel 1/4" stereo headphone output
Speaker Selector	A/B speaker selection
Power Switch	Main power on/off with indicator light
Volume/Balance	Dual concentric controls

Installation

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

Connect speakers: Use speaker terminals A and/or B for 4-16 ohm speakers.
Connect audio sources: Phono for turntable, Aux for CD player, Tape for recorders.
Connect antenna: FM 300 ohm terminals for dipole antenna.
Plug into AC power outlet (120V 60Hz).

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

First-Time Setup

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

Select input source: Turn selector to Phono, Aux, or Tape position.
Adjust volume: Start at minimum, gradually increase to desired level.
Set tone controls: Bass and treble at center position for flat response.
Tune FM station: Use tuning knob and signal meter for best reception.

CAUTION! Always turn volume to minimum before powering on or changing sources.

Specifications

Power Output: 70 watts per channel RMS at 8 ohms
Frequency Response: 10Hz - 50kHz (+0 -1dB)
Total Harmonic Distortion: 0.15% at rated power
Input Sensitivity: Phono: 2.5mV, Aux: 250mV
Signal-to-Noise Ratio: Phono: 75dB, Aux: 90dB
Tuning Range: FM 88-108MHz, AM 530-1600kHz
Dimensions: 18-3/4" W x 6-1/4" H x 15-3/4" D
Weight: 38 lbs
Power Requirements: 120V AC, 60Hz, 400 watts max

Controls and Settings

Front Panel: Power switch, input selector, volume/balance, bass, treble, loudness, filters, tuning knob, signal meter.

Rear Panel: Speaker terminals, input jacks, antenna terminals, AC outlet, fuse holder.

Tone Controls: Bass ±10dB at 50Hz, Treble ±10dB at 10kHz. Filters: High cut 7kHz, Low cut 50Hz. Loudness: Compensates for Fletcher-Munson curve. Balance: Adjusts left/right channel balance.

Connecting Components

Speaker Connections: A/B terminals for 4-16 ohm speakers. Inputs: Phono (MM cartridge), Aux (line level), Tape 1/2.

Turn off power before making connections.
Connect turntable to Phono inputs (ground wire to ground terminal).
Connect CD player to Aux inputs.
Connect tape deck to Tape inputs/outputs.
Connect FM antenna to 300 ohm terminals.

Tip: Use high-quality cables and ensure secure connections.

Operation Guide

Basic operation procedures for optimal performance.

Power On: Switch to ON position; wait for protection circuit to engage.
Source Selection: Choose Phono, Aux, or Tape position.
Volume Control: Adjust gradually; use loudness for low-level listening.
Tone Adjustment: Set bass and treble to taste.
FM Tuning: Rotate knob until signal meter peaks and center meter zeros.
Speaker Selection: Choose A, B, or both for multiple speaker pairs.
Tape Monitoring: Engage for recording or playback monitoring.

WARNING! Do not operate without proper load on speaker terminals.

Maintenance

Regular maintenance ensures long-term reliability.

Cleaning: Use soft, dry cloth for exterior; wood cabinet use appropriate cleaner.
Ventilation: Keep vents clear of obstruction.
Fuse Replacement: Use only specified 5A 250V fuse.
Deoxit: Clean controls periodically with contact cleaner if scratchy.

CAUTION! Unplug before cleaning or servicing. No user-serviceable parts inside.

Regulatory Information

FCC Part 15: Class B computing device compliance. Manufactured by Marantz Company, Inc. under Superscope, Inc. Original manufacture 1974-1977. For historical reference and service information, consult authorized Marantz service centers. This product may contain materials regulated for disposal.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound	Protection mode/speakers	Check speaker connections; ensure proper impedance; wait for protection reset.
Distorted sound	Overload/connections	Reduce volume; check input levels; verify proper grounding.
FM reception poor	Antenna/alignment	Reposition antenna; check connections; use outdoor antenna for weak areas.
Scratchy controls	Oxidation	Clean controls with contact cleaner; rotate knobs through full range.
Lights not working	Bulbs/power	Replace dial lamps; check fuse; verify AC power.

Service: Consult qualified technician for internal repairs.

Note: Original tubes and components may require replacement due to age.