EasyManua.ls Logo

Marantz 125 Service Manual

Marantz 125
32 pages
To Next Page IconTo Next Page
To Next Page IconTo Next Page
Page #1 background imageLoading...
Page #1 background image
Question and Answer IconNeed help?

Do you have a question about the Marantz 125 and is the answer not in the manual?

Marantz 125 Specifications

General IconGeneral
Tuning BandsFM, MW
FM Tuning Range88 to 108 MHz
Distortion (FM)0.3%
Selectivity (MW)30 dB
Output Level775 mV
Weight8.2 kg
Tuning ScaleAnalog
Sensitivity (FM)1.8 µV
Signal to Noise Ratio (MW)50 dB
Selectivity (FM)60dB (FM)
Frequency Response (FM)30 Hz to 15 kHz
Capture Ratio (FM)1.5 dB
Power Supply120V, 60Hz

Summary

Introduction

AM TUNER

AM TUNER TROUBLESHOOTING

Guides on diagnosing and fixing issues within the AM tuner section.

AM ALIGNMENT PROCEDURES

Step-by-step instructions for aligning the AM tuner section, including IF and frequency range.

FM TUNER

MULTIPLEX STEREO DECODING CIRCUIT

Details the MPX stereo decoding circuit, including the Phase Locked Loop (PLL) IC.

AUDIO MUTING AND STEREO MODE AUTO-SELECTION CIRCUITS

Explains the audio muting and stereo mode auto-selection circuits.

TEST EQUIPMENT REQUIRED FOR SERVICING

SYMPTOM: TOTAL OR PARTIAL LOSS OF STEREO SEPARATION

SEPARATION ADJUSTMENT

Procedure for adjusting stereo separation on the tuner.

SYMPTOM: POOR FM SENSITIVITY

SYMPTOM: EXCESSIVE DISTORTION

SENSITIVITY AND DISTORTION FRONT END ALIGNMENT

Alignment procedure for the FM front end to optimize sensitivity and reduce distortion.

DISTORTION – DISCRIMINATOR ALIGNMENT

Procedure for aligning the discriminator stage to minimize distortion.

NO FM OUTPUT

MISCELLANEOUS ADJUSTMENTS

SIGNAL STRENGTH METER ADJUSTMENT

Procedure to calibrate the signal strength meter.

MUTING LEVEL/STEREO THRESHOLD LEVEL ADJUSTMENT

Steps for adjusting muting and stereo threshold levels.

FM DOLBY LEVEL ADJUSTMENT

Procedure for adjusting the FM Dolby level.

Parts List

TECHNICAL SPECIFICATIONS

FM SECTION

Performance specifications for the FM tuner section of the unit.

AM SECTION

Performance specifications for the AM tuner section of the unit.

GENERAL

General specifications including power, dimensions, and weight.

SERVICE INFORMATION FOR EUROPEAN MODEL

VOLTAGE CONVERSION

FTZ REGULATION

Related product manuals