Marantz 2270 Manual PDF

The Marantz 2270 is a classic stereo receiver from the 1970s featuring 70 watts per channel, high-quality analog components, FM/AM tuner, phono inputs, tape monitoring, loudness control, and distinctive blue dial lighting. Below are key sections covering specifications, features, operation, connections, maintenance, and troubleshooting for this vintage audio equipment.

1. Features at a Glance 2. Installation & Setup 3. Specifications 4. Front Panel Controls 5. Rear Panel Connections 6. Operation Guide 7. Tuner Operation 8. Maintenance & Care 9. Technical Specifications 10. Troubleshooting

Features at a Glance

Key components: 70W RMS per channel stereo amplifier, FM/AM tuner, phono inputs, tape monitor, tone controls, and distinctive Marantz styling.

Feature	Description
Power Output	70 watts per channel RMS at 8 ohms
Tuner Section	FM stereo and AM reception
Phono Inputs	MM phono cartridge compatible
Tape Monitoring	Dual tape monitor circuits
Tone Controls	Bass, treble, and midrange adjustment
Loudness Control	Compensates for low volume listening
Headphone Jack	Front panel 1/4" headphone output
Filter Switches	High and low frequency filters
Speaker Selector	A/B speaker selection
Power Meter	Dual VU meters for power output display

Installation & Setup

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

Connect speakers: Use speaker wire to connect to A or B speaker terminals.
Connect audio sources: Turntable to PHONO inputs, CD player to AUX inputs.
Connect antenna: FM antenna to 300 ohm terminals, AM antenna to AM terminal.
Plug into AC power outlet.
Set impedance selector to match your speakers (4 or 8 ohms).

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

Specifications

Power Output: 70 watts per channel RMS at 8 ohms
Total Harmonic Distortion: 0.3% at rated power
Frequency Response: 10Hz to 50kHz (+0, -3dB)
Input Sensitivity: Phono: 2.5mV, Aux: 250mV
Signal-to-Noise Ratio: Phono: 70dB, Aux: 90dB
Tuner Section: FM stereo, AM reception
Dimensions: 17-3/4" W × 6" H × 15-1/2" D
Weight: 35 lbs
Power Requirements: 120V AC, 60Hz

Front Panel Controls

Left to right: Power switch, speaker selector, input selector, tone controls, balance, volume, tuning knob, function switches.

Detailed Controls: POWER ON/OFF, SPEAKERS A/B, INPUT SELECTOR (Phono, Aux, Tuner, Tape), BASS control, TREBLE control, BALANCE control, VOLUME control, TUNING knob, FUNCTION switches (Loudness, Mono, High Filter, Low Filter), HEADPHONE jack, TUNING meter, POWER meters.

Rear Panel Connections

Speaker terminals, input jacks, antenna connections, AC power cord.

Speaker Outputs: A and B speaker terminals (4-16 ohms)
Input Jacks: Phono, Aux, Tape Play/Record
Antenna Connections: FM 300 ohm, FM 75 ohm, AM antenna
AC Outlets: Switched and unswitched accessory outlets
Impedance Selector: 4 or 8 ohm speaker matching

Tip: Use proper gauge speaker wire and ensure secure connections.

Operation Guide

Basic operation steps for different audio sources.

Turn on power: Rotate volume to minimum before power on.
Select input: Choose Phono, Aux, or Tuner as needed.
Adjust volume: Start with low volume and increase gradually.
Use tone controls: Adjust bass and treble to preference.
Speaker selection: Choose A, B, or both speaker sets.
Tape monitoring: Use tape monitor for recording/playback.

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

Tuner Operation

FM and AM radio reception and tuning.

Select Tuner input on front panel.
Extend FM antenna for best reception.
Rotate tuning knob until station is centered on tuning meter.
For stereo FM, ensure stereo indicator is lit.
Use signal strength meter to optimize antenna position.
For weak stations, use mono mode to reduce noise.

Tip: Proper antenna positioning is crucial for good FM reception.

Maintenance & Care

Unplug before cleaning. Use soft, dry cloth for exterior. Clean controls with contact cleaner if noisy.

CAUTION! Do not use liquids or solvents on wood cabinet. Keep away from moisture and extreme temperatures.

Technical Specifications

Parameter	Specification
Power Output	70W/ch at 8Ω, 20Hz-20kHz
THD	0.3% at rated power
Damping Factor	55 at 8Ω
Input Impedance	Phono: 47kΩ, Aux: 100kΩ
Phono Overload	150mV at 1kHz
Capture Ratio	1.5dB
Selectivity	70dB
Image Rejection	80dB
IF Rejection	90dB

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound	Speaker connections/input selection	Check speaker wires; verify input selection; ensure volume up.
Distorted sound	Overload/incorrect settings	Reduce volume; check source level; verify impedance setting.
No FM reception	Antenna connection	Check FM antenna connection; reposition antenna.
Hum or noise	Grounding issues	Ensure proper grounding; check cable connections.
One channel dead	Connection/balance control	Check balance control; verify cable connections; test speakers.
Scratchy controls	Dirty potentiometers	Clean controls with contact cleaner; rotate controls fully.
Lights not working	Bulb failure	Replace dial lights and meter bulbs with correct replacements.

Service: For technical service, consult qualified Marantz technician. Original schematics available from authorized service centers.

Note: This vintage equipment may require capacitor replacement and other maintenance for optimal performance.