Marantz SM-8 Service Manual

MARANTZ
MODEL
Sm-8
STEREO
POWER
AMPLIFIER
wenan eran cul.
INTRODUCTION
This service manual was prepared for use by Authorized
Warranty Staions and contains service information for the
Marantz Model Sm-8 Stereo Power Amplifier.
Servicing information and voltage data included in this
manual are intended for use by knowledgeable and ex-
perienced personnel only. All instructions should be read
carefully. No attempt should be made to proceed without a
good understanding of circuitry operation.
The parts list furnishes complete ordering information. Most
replacement parts should be ordered from the Marantz
Company. However, a simple description is included for
parts which can be obtained locally.
1. SHOCK, FIRE HAZARD SERVICE TEST
CAUTION: After servicing this appliance and prior to
returning to customer, measure the resistance between either
primary AC cord connector pins (with unit NOT connected
to AC mains and its Power switch ON), and the face or front
Panel of product and controls and chassis bottom.
Any resistance measurement less than 1 Megohms should
cause unit to be repaired or corrected before AC power is
applied, and verfied before return to user/customer.
Ref. UL Standard No. 1270. Para. 66. 3. D (Mandatory Test
after servicing Electrical Appliances, effective 7-1-83).
2. FEATURES
@ High power — 120W x 2 of dynamic “Marantz” sound
From the line input, the audio signal passes to the dual
FETs in the buffer amp and then to the first stage which
is a differential amplifier using dual transistors. One
side of this differential output is phase inverted, while
the output of the buffer amp passes to a pure push-pull
amplifier which drives the final output stage. The power
amplifier stage uses newly developed super high fT power
transistors in parallel three-stage Darlington connection.
This makes possible handling high currents with sufficient
heat radiating capacity.

Marantz SM-8 Specifications

General

Brand	Marantz
Model	SM-8
Category	Amplifier
Language	English