Allen heath gr1 mixer service manual

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ALLEN & HEATH 2 R1SM1 INTRODUCTION The information presented in this manual is intended for competent technical personnel to carry out service and product support for the GR1. We assume that the reader is familiar with the related electronic theory and audio terminology, and is able to carry out basic servicing, fault-finding and repair of audio equipment of this type. Service personnel should also be familiar with audio systems, mains earthing and power requirements, as well as handling precautions. For further information on the operation and application of the GR1 please refer to the USER GUIDE publication AP2057 supplied with each unit. Whilst we believe the information in this manual to be reliable we do not assume responsibility for inaccuracies. We also reserve the right to make changes in the interest of further product development. SERVICE AND TECHNICAL SUPPORT Under normal conditions the GR1 does not require user maintenance or internal calibration. Any service work required should be carried out by qualified technical personnel only. We are able to offer further product support through our worldwide distribution network. To help us provide the most efficient service please would you quote the console serial number in any communication regarding this product. copyright © 2002 ALLEN & HEATH Ltd. All rights reservedPublication......................AP2059 Issue 2 This manual is printed in three sections: SECTION A is a reprint of the USER GUIDE for quick reference.This may also assist the service agent in dealing with user related problems. From our experiences with customer problems, most are due to incorrect use or installation of the console and/or connected equipment. This is often due to the customer not reading or misinterpreting the instructions in the user guide. SECTION B provides technical descriptions, service procedures, and how to order spare parts. The contents of the standard service agent spares kits are also listed. SECTION C provides a complete set of circuit diagrams, printed circuit and assembly drawings. SAFETY WARNING ! Mains electricity is dangerous and can kill. Mains voltage is present within the GR1. Do not remove the top cover with mains connected. Do not carry out any work within the unit while it is powered except for installation calibration. High voltage components are insulated for safety but should not be touched with power applied. The mains voltage setting is factory wired and marked on the rear panel. Check that this matches your local mains supply. Check your mains wiring and earthing before switching on. DO NOT REMOVE THE MAINS EARTH CONNECTION! The chassis is always connected to mains earth regardless of any settings of the Ground (earth) Lift option links.

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ALLEN & HEATH 3 R1SM1 CONTENTS SECTION A INTRODUCTION................................................................................................................ 1 SERVICE & TECHNICAL SUPPORT................................................................................. 1 PRECAUTIONS .................................................................................................................. 1 INTERCONNECTIONS ....................................................................................................... 2 ADJUSTING THE LEVELS ................................................................................................. 2 SPECIFICATION................................................................................................................ 3 CONNECTIONS................................................................................................................. 3 INSTALLATION.................................................................................................................. 4 CONNECTING POWER..................................................................................................... 4 FRONT PANEL CONTROLS .............................................................................................. 5 CONFIGURATION.............................................................................................................. 6 EARTHING THE AUDIO SYSTEM..................................................................................... 7 MIC INPUTS....................................................................................................................... 7 LINE INPUTS...................................................................................................................... 8 CHANNEL DIRECT OUTPUTS.......................................................................................... 8 ROUTING THE CHANNELS............................................................................................... 9 L,R,M SYS-LINK INPUT/OUTPUT..................................................................................... 9 MAIN OUTPUTS................................................................................................................. 9 PRIORITY DUCKING SYSTEM.......................................................................................... 10 COMPRESSOR/LIMITERS................................................................................................ 10 REMOTE CONTROL .......................................................................................................... 11 ALARM OVERRIDE............................................................................................................ 12 INPUT EXPANSION WITH SYS-LINK ............................................................................... 13 OUTPUT EXPANSION WITH SYS-LINK........................................................................... 14 BLOCK DIAGRAM.............................................................................................................. 15 SECTION B TECHNICAL DESCRIPTION.............................................................................................. 2 WHEN A FAULT IS SUSPECTED...................................................................................... 3 REMOVING THE PCB........................................................................................................ 4 VCA CALIBRATION............................................................................................................ 5 ORDERING SPARE PARTS .............................................................................................. 6-7 SECTION C TECHNICAL BULLETINS................................................................................................... 2 FRONT & REAR PANEL LAYOUT..................................................................................... 3 BLOCK DIAGRAM.............................................................................................................. 4 INTERNAL LAYOUT........................................................................................................... 5 PCB COMPONENT IDENT................................................................................................ 6 PCB COMPONENT VALUES............................................................................................. 7 CIRCUIT DIAGRAMS (11 pages) .......................................................................................8-18 AC MAINS VOLTAGE......................................................................................................... 19