YORKVILLE Audiopro 3400 Service Manual

SERVICE MANUAL
3
400
HIGH EFFICIENCY STEREO POWER AMPLIFIER
U.S.A.
Yorkville Sound Inc.
4625 Witmer Industrial Estate
Niagara Falls, New York
14305 USA
Voice: (716) 297-2920
Fax: (716) 297-3689
WORLD HEADQUARTERS
CANADA
Yorkville Sound
550 Granite Court
Pickering, Ontario
L1W-3Y8 CANADA
Voice: (905) 837-8481
Fax: (905) 837-8746
Quality and Innovation Since 1963
Printed in Canada

YORKVILLE Audiopro 3400 Specifications

General

Channels	2
Input Impedance (Balanced/Unbalanced)	20k Ohms / 10k Ohms
Frequency Response	20Hz-20kHz
Signal-to-Noise Ratio	>100dB
Input Connectors	XLR and 1/4" TRS
Output Connectors	Binding posts
THD	<0.1%
Slew Rate	>20V/uS
Protection	Thermal, short circuit, DC protection
Controls	Level controls, mode switch (stereo/bridge)
Indicators	Power, Protect, Signal, Clip

Summary

Important Safety Instructions

General Safety Precautions and Servicing

Covers essential safety warnings, including not opening the unit, referring to qualified service personnel, and general operating precautions.

M1012A 'The Input Board'

M1011A 'Voltage Amplifiers and System Control'

M1002A 'Current Amplifier Board'

DC Protection Circuitry

EMS Circuit

Fan Circuitry

Thermal Shutdown Circuit

Specifications

Output Power Ratings

Details power output for one channel, both channels, and bridged modes across different loads and conditions.

Distortion and Frequency Response

Provides THD distortion figures and frequency response characteristics.

Identifying Defective Boards

Visual Inspection (Front Panel & Fan)

Guide for checking front panel indicators and fan behavior for initial fault diagnosis.

Visual Inspection (Internal Chassis)

Procedure for inspecting internal components for signs of damage like charring or burnt parts.

Power Up Procedure (Without M1002 Boards)

Safe power-up sequence for testing the M1011 board before connecting other modules.

Dismantling and Reassembly Precautions

Important safety and handling guidelines for disassembling and reassembling the unit.

Testing Repaired Circuit Board

Post-Repair Testing Procedure

Steps for powering up and testing repaired M1002/M1002A boards using test connectors and oscilloscopes.

Quick Fix for M1002 and M1002A

Component Replacement Procedure

Detailed steps for replacing transistors, diodes, and resistors as part of the Quick Fix kit.