Marantz 3800 - Section 1 GENERAL INFORMATION AND OPERATING PRINCIPLES; Manual Purpose and Scope; Model 3800 Overview and Features; Description and Operation of Model 3800

Section 1
GENERAL
INFORMATION
AND
OPERATING
PRINCIPLES
|
1. INTRODUCTION
This manual was prepared for service technicians
in factory-authorized warranty repair stations and
other equally-qualified and equipped service cen-
ters. The service information contained herein is
applicable to the Model 3800 Stereo Control
Console, a stereo preamplifier manufactured by
the Marantz Company, Inc., a subsidiary of
Superscope
Incorporated,
Chatsworth,
California
91311.
2. GENERAL
Section 1 describes physically and functionally the
Model 3800 Stereo Control Console,a professional,
state-of-the-art stereo preamplifier with the Dolby
noise reduction (NR) circuit. Use, application,
performance and design features are also described.
Mechanical parts are high-quality, selections for
reliability and economy. Electronic components
in the Model 3800 circuits are precision devices
selected for their long operating life. The Model
3800 is thereby assured of providing continuous
high-quality performance.
System, functional, and detail descriptions include
the major mechanical functions and control
electronics. Specifications and capabilities are
both technical and performance related.
3. DESCRIPTION AND
OPERATION
This section is included to assist the service tech-
nician in understanding the operation of the
Model 3800. The technical data describe the basic
system functions and circuit theory of operation.
A.FUNCTIONAL DESCRIPTION
F igure 1-1 is a Functional Block Diagram of the
Model 3800 left audio channel, showing the
principal circuit elements and signal flow paths.
Additional functional and detailed reference
support data are illustrated on Figures 1-2
through 1-4: Wiring, and Dolby NR Circuit
Signal Processing Diagrams, respectively.
B. OPERATING PRECAUTIONS
WARNING:
TO
PREVENT
FIRE
OR
SHOCK
HAZARD,
DO
NOT
EXPOSE
THIS
INST
RU-
MENT
TO
RAIN
OR
MOISTURE.
CAUTION: ENSURE THAT THE TOTAL
POWER OUTPUT CONNECTED TO THE
SPEAKER SWITCHING INPUTS DOES NOT
EXCEED 250 WATTS RMS PER CHANNEL,
CONTINUOUS POWER.
CAUTION: DO NOT EXCEED THE MAXI-
MUM TOTAL POWER RATINGS OF THE
AC OUTLETS. THE POWER SWITCH AND
OTHER CIRCUITRY IN THE MODEL 3800
MAY BE DAMAGED IF SUBJECTED TO
EXCESSIVE CURRENT.
CAUTION: TURN VOLUME CONTROL CCW
TO MINIMUM BEFORE SWITCHING SPE AkK-
ER UNITS TO PREVENT POSSIBLE DAM.-
AGE TO YOUR LOUDSPEAKERS.
C. SYSTEM OPERATION
High- and low-level inputs (program sources) are
selected by the Program Selector Pushswitches
and applied in accordance with signal level.
When low-level sources are selected (PHONO or
MIC), the Program Selector Pushswitch applies
the input signal to the Phono/Mic Amp) fier
circuit and selects the proper equalization,
RIAA or Mic. The output of the Phono/Mic
Amplifier
is
then
returned
to
the
Prog-am
Selector Pushswitches where it is handle# as
another high-level input.
High-level input signals TUNER, AUX, TAPE 1,
TAPE 2 or the output of the Phono/Mic An pii-
fier are applied to the Dolby encoder/dec) der
4-1