Marantz 2015 User Manual

INTRODUCTION
This service manual was prepared for use by Authorized Warranty Stations and contains service
information for Marantz Model 2015 Stereophonic Receiver.
Servicing information and voltage data included in this manual are intended for use by the
knowledgeable and experienced technician only. All instruction should be read carefully. No
attempt should be made to proceed without a good understanding of the operation in the
receiver.
The parts list furnish information by which replacement part may be ordered from the
Marantz Company. A simple description is included for parts which can be usually be obtained
through local suppliers.
1. Service Notes
As can be seen from the circuit diagram, the chassis of Model 2015 consists of the following
units. Each unit mounted on a printed circuit board is described within the square enclosed by a
bold dotted line on the circuit diagram.
1 EM/AM TUNeT idee ce ot on dee Pe dict swe bi had ou nesas mounted on P. W. Board P100
2. MPX Stereo Indicator .... 0... ccc cee ee ees mounted on P. W. Board P200
3. Phono Amplifier ..... 0.0.0... ccc cee ee eee eee mounted on P. W. Board P300
4. Tape Mon, Mono, Loudness and Muting Switch Unit ....... mounted on P. W. Board P400
5. Tone Amplifier .... 0... cc ce eee ee eee e eee e nes mounted on P. W. Board P500
6. Power Amplifier ....... 00.0... ccc eee eee sea aha mounted on P. W. Board P600
7. Temperature Compensation unit ........... 0.020 e ees mounted on P. W. Board P700
8. Power Supply ....... 00. cc eee eee eee eee ete eens mounted on P. W. Board P800
2. AM Tuner
All components except ferrite bar antenna are mounted on a printed circuit board P100.
The AM signals induced in a ferrite bar antenna are applied to the base of converter transistor
H113 through a capacitor of C171, while the local oscillator voltage is injected to the emitter of
H1i13 through a capacitor C172. Both AM signals and oscillating voltage are mixed at the
base-emitter junction and converted into 455KHz intermediate frequency. The resulting IF signal
is applied to the first IF transformer L116 consisting of one ceramic filter and two tuned circuits.
The output of L116 is led to the transistor H104 which in turn apply its output to the
transistor of next stage H105. The fully amplified [IF output is then applied to the diode H123 to
detect audible signa! through the detector transformer L117. The detected audio signa! is filtered
and the final audio output is obtained from the pin terminal J118 and applied to the func-
tion switch.
The DC component of the detected IF signal is used as a AGC voltage to control emitter
current of H104 through the resistor R185. A part of IF signal output is also applied to the diode
H124 through a capacitor C180 and rectified to obtain DC current for energizing the AM signal
strength meter M001.
2.1 Suggestions for AM Tuner trouble shooting
Check for broken AM bar antenna, next try to tune station by rotating fly-wheel tuning knob
slowly and observe the AM signal strength meter whether it deflects or not. If the signal strength
meter gives a deflection at several frequencies received, no failure may exist in the stages at least
preceding final IF transformer L117. Next connect a oscilloscope to the pin terminal J118 and
check for audio signals with the tuning meter deflected. If the signal strength meter does not
deflect, check the local oscillator circuit. Normal oscillating voltage at the hot end of the
oscillator tuning capacitor is about 2 or 3 volts, varying with tuning capacitor position. When
measuring oscillating voltage use a RF VTVM, no circuit tester gives correct indication. If the
local oscillator voltage is normal, check all voltage distribution in the AM circuits by using a DC
VTVM and compare the measured values with those given in the schematic diagram.

Marantz 2015 Specifications

General

Power Output	15 watts per channel into 8Ω (stereo)
Frequency Response	20Hz to 20kHz
Total Harmonic Distortion	0.8%
Input Sensitivity	2.2mV (MM), 180mV (line)
Tuning Range	FM, MW
Speaker Load Impedance	4Ω to 16Ω
Output	Headphones