Carver M-1.5 - Service Manual

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Summary

CARVER M-1.5 Circuit Description

Introduction

Overview of the magnetic-field power amplifier design and its operational benefits.

Amplifier Card Circuit Description

Details on input stages, clipping eliminator, and driver circuits.

Primary Regulator Card

Explanation of the primary regulator circuit's functions and components.

Main Supply Board

Details on the main power supply board operation and voltage regulation.

Shutdown Protection Features

Description of active shutdown protection for various fault conditions.

Display Board Operation

Explanation of the LED display indicators for power and output levels.

CARVER M-1.5 Test Procedures

Equipment List

List of required instruments for testing the amplifier.

Presets

Steps for preparing the unit and setting up test parameters before testing.

DC Supply Level Checks

Procedure for verifying critical DC voltage outputs on the supply board.

Amp Cards Tests

Steps to test frequency response, output power, and commutator operation.

Protection Circuitry

Procedures to verify the functionality of various protection circuits.

CARVER M-1.5 Troubleshooting Guide

No Power (all LEDs fail to light)

Steps to diagnose and resolve no-power conditions and dead unit symptoms.

Fault LED lights when power is applied

Troubleshooting for fault LED activation and identifying the specific fault sensor.

DC-Offset

Diagnosing and rectifying DC offset and low-frequency differential problems.

Over-current, high frequency shutdown is activated

Troubleshooting for over-current and high-frequency protection trips.

Over-voltage sensor is activated

Troubleshooting for over-voltage protection activation and causes.

Excessive current draw before triac fires

Diagnosing excessive current draw before triac activation.

Excessive current draw after triac fires

Diagnosing excessive current draw after triac activation.

Early clipping on one side of waveform

Troubleshooting issues with clipping on one audio channel.

Clips early, both channels

Diagnosing clipping issues affecting both audio channels.

Clipping eliminator not working

Troubleshooting the clipping eliminator circuit functionality.

Excessive noise

Diagnosing and resolving excessive noise in the amplifier output.

Excessive turn-off thumps

Troubleshooting excessive turn-off thumps from the amplifier.

CARVER M-1.5 Schematics and Board Locators

Amp Card Schematics and Locators

Diagrams and component layout locators for amplifier circuit boards.

Power Supply Schematics and Locators

Diagrams and component layout locators for power supply and regulator boards.

Display Card Schematics and Locators

Diagrams and component layout locators for the display circuit board.

CARVER Service Bulletins

Bulletin M-1.5 t-1: Right Channel Buzz Correction

Procedure to fix excessive buzz on the right channel due to shorted inputs.

Bulletin M-1.5 t-2: Capacitor Replacement Procedure

Instructions for replacing unavailable dual capacitors with an assembly.

Carver M-1.5 Specifications

General

Frequency Response	20 Hz to 20 kHz
Input Sensitivity	1.5V
Signal to Noise Ratio	100 dB
Damping Factor	200
Dimensions	19 x 3.5 x 10.5 inches