ALLEN & HEATH WZ312M User manual

ALLEN&HEATH WZ312M AP6770 Issue 1 Page - 1 - of 10
WZ
3
12M
ALLEN&HEATH
SERVICE MANUAL
Copyright © 2007 Allen & Heath Limited. All rights reserved
Allen & Heath Limited
Kernick Industrial Estate, Penryn, Cornwall, TR10 9LU, UK
http://www.allen-heath.com

ALLEN&HEATH WZ312M AP6770 Issue 1 Page - 2 - of 10
Release notes for this issue
Limited One Year Warranty
This product is warranted to be free from defects in materials or workmanship for period of
one year from the date of purchase by the original owner. To ensure a high level of
performance and reliability for which this equipment has been designed and manufactured,
read this User Guide before operating. In the event of a failure, notify and return the
defective unit to ALLEN & HEATH Limited or its authorised agent as soon as possible for
repair under warranty subject to the following conditions
Conditions of Warranty
The equipment has been installed and operated in accordance with the instructions in this
User Guide. The equipment has not been subject to misuse either intended or accidental,
neglect, or alteration other than as described in the User Guide or Service Manual, or
approved by ALLEN & HEATH. Any necessary adjustment, alteration or repair has been
carried out by ALLEN & HEATH or its authorised agent. This warranty does not cover fader
wear and tear. The defective unit is to be returned carriage prepaid to ALLEN & HEATH or its
authorised agent with proof of purchase. Units returned should be packed to avoid transit
damage. In certain territories the terms may vary. Check with your ALLEN & HEATH agent
for any additional warranty which may apply.
For further assistance please contact our distributor or your territory.
http://www.allen-heath.com/UK/distributors.asp

ALLEN&HEATH WZ312M AP6770 Issue 1 Page - 3 - of 10
CONTENTS
DEVELOPMENT CHANGES
SERVICING PRECAUTIONS AND GENERAL NOTES
PARTS IDENTIFICATION
•How to order parts
•Exterior parts
•Interior parts
SOFTWARE & FIRMWARE
SPECIFICATION

ALLEN&HEATH WZ312M AP6770 Issue 1 Page - 4 - of 10
DEVELOPMENT CHANGES
NOTE: These changes have been implemented at the factory as part of our ongoing
development policy.
They are not critical to the basic function of the unit.
It is for the owner / service engineer to decide to update a unit with development changes.

ALLEN&HEATH WZ312M AP6770 Issue 1 Page - 5 - of 10
Servicing Precautions – General Notes
Service personnel:
Service work should be carried out by technically qualified service personnel only.
Mains power is dangerous and can kill. Do not attempt to work on a linear or switched
mode power supply if you are not suitably qualified to do so. Do not attempt to repair
surface mount circuit assemblies unless you are suitably qualified and have the
necessary facilities to do so. Replacement circuit assemblies can be ordered.
Service facilities:
Ensure a suitably sized work surface is available. Ensure this is clear of dirt, debris and
obstructions which may damage the equipment surfaces. Ensure adequate lighting.
Use the correct tools for the job and ensure they are in good working order. Ensure all
workshop safety requirements are adhered to.
Service information:
Check that you have all the information you need before starting the service job. Refer
to the Allen & Heath web site or contact Allen & Heath technical support for details on
the latest information. Full technical information can be downloaded from the web site
Distributor Zone (password required).
Mains power:
Connect the equipment to mains power only of the type described in the user guide and
marked on the rear panel. The power source must provide a good ground connection.
Ensure you always use an isolation transformer when working on any mains power
supply unit.
Mains cord and fuse:
Use the correct power cord as supplied with the equipment. Do not remove or tamper
with the ground connection in the power cord. Heed the Important Mains Plug Wiring
Instructions printed in the user guide if it is necessary to rewire the mains cord. Always
replace the equipment mains fuse with the correct type and rating as described in the
user guide and marked on the equipment panel.
Opening the unit:
Switch off and remove the mains power cord before opening the equipment. Ensure all
power supply covers and safety shields are in place before applying power with the unit
open for diagnostic fault finding.
Closing the unit:
Before finishing, check the quality and accuracy of the service work carried out.
Remove any dirt or debris as this may cause equipment failure in the future. Ensure all
assemblies, harnesses and connectors are correctly aligned and plugged in. Ensure
that jumper settings and control configurations are correctly set according to the
requirements of the customer.
Continued -

ALLEN&HEATH WZ312M AP6770 Issue 1 Page - 6 - of 10
Testing the unit:
Before operating the equipment, read and adhere to the Important Safety Instructions
printed in the user guide. Test that the service work has been successfully carried out.
Shipping the unit:
Use adequate packing such as the original packaging or purpose designed flight case if
you need to ship the unit. To avoid injury to yourself or damage to the equipment take
care when lifting, moving or carrying the equipment.
Operation:
To test the console make sure it is connected as described in the user guide. Check
that the voltage setting marked on the rear panel is correct for the local mains supply.
Fault finding:
For effective fault diagnosis trace the signal flow through the circuit path. Refer to the
system block diagram. Replacement circuit assemblies are available from Allen &
Heath.

ALLEN&HEATH WZ312M AP6770 Issue 2Page - 7 - of 10
How to order parts
Parts must be ordered from our distributor in your territory. A list of international
distributors can be viewed at http://www.allen-heath.com/UK/distributors.asp
UK parts must be ordered through an appointed A&H dealer or service centre. A list of UK
service centres can be viewed at http://www.allen-heath.com/UK/service_centres.asp
PARTS IDENTIFICATION
EXTERIOR PARTS
AJ6278
AJ2961
AJ2864
AJ2074A
AJ2077A
AJ2076A
AJ2078A
AJ3503
AJ2075A
AJ2079A
AJ2962
AJ3955
AJ3503
AJ6237
AJ6691
AJ8079
AJ8080
AB0215
Fader
screw
003-282JIT
AL5903 AL5323
AI8004
EQ
boost/cut
AI3838
Gain
AI8005
EQ
frequency
sweep
AI3838
Channel
level
Aux
1,3,5,7,9,11
AI8006
Aux
2,4,6,8,10,
12
AI6718
003-672JIT Fader
AI8007

ALLEN&HEATH WZ312M AP6770 Issue 1 Page - 8 - of 10
Side moulding
Left AA5463-L
Side moulding
Right AA5463-R
AB2810
XLR screw AJ8071
AJ2887
AC. Black
switch cap

ALLEN&HEATH WZ312M AP6770 Issue 1 Page - 9 - of 10
INTERIOR PARTS
003-171JIT
PSU PCB
003-647JIT
Rear
connector
PCB
Feet AK0102
003-644JIT
Mono input PCB
003-645JIT
Mix master 8/12
PCB
003-646JIT
Mix master 7/11
PCB
003-665JIT
Mix master 6/10
PCB
003-667JIT
Mix master 5/9
PCB
003-668JIT
Master meter
LED PCB
003-669JIT
MASTER
Distribution PCB
003-850JIT
Headphone
PCB
003-669JIT
MONO Distribution
PCB

ALLEN&HEATH WZ312M AP6770 Issue 1 Page - 10 - of 10
SPECIFICATION
Performance
Maximum output level
XLR +26dBu into 600 ohms max load
Jack +21dBu into 2k ohm max load
Internal headroom Channels +21dB
Mix +23dB
Meters 3 colour LED, quasi peak response
Sensitivity 0VU = +4dBu at XLR output
Master meters 12 segment -30 to +16dB
Channel meters 2 segment -12, +16dB (5dB before clip)
Frequency response 20Hz to 50kHz +/-0.5dB
THD+n at +10dBu 1kHz Channel to mix out < 0.004%
Crosstalk at 1kHz Fader shutoff >90dB
Channel mute >95dB
Inter channel >90dB
Noise, rms 22Hz to 22kHz Mic EIN -128dB
Residual output noise < -92dBu (-96dB S/N)
LR unity fader mix noise < -80dBu (-84dB S/N)
Channel HPF 12dB/octave below 80Hz
Mono EQ HF Shelving, +/-15dB, 12kHz
HM Peak/dip, +/-15dB, 500Hz to 15kHz, Q=1.8
LM Peak/dip, +/-15dB, 35Hz to 1kHz, Q=1.8
LF Shelving, +/-15dB, 80Hz
Stereo EQ HF Shelving, +/-15dB, 12kHz
HM Peak/dip, +/-15dB, 2.5kHz, Q=1.8
LM Peak/dip, +/-15dB, 250Hz, Q=1.8
LF Shelving, +/-15dB, 80Hz
Power supply Internal 100-240V, 50/60Hz auto sensing, IEC input
External Input for optional MPS12 backup supply
Power consumption 45W max
Mains fuse T630mA L 20mm
Mechanical
Free standing dimensions W 507 (20”) x D 530 (20.9”) x H 194 (7.7”)
Rack mounted W 483 (19”) x D 122 (4.8”) x H 444 (17.5”) 10U
Underside connectors
Rack mounted W 483 (19”) x D 193 (7.6”) x H 497 (19.6”) 11.2U
Rear connectors
Weight 12kg (27lbs)
Connections
Mono channel XLR balanced pin 2 hot Sensitivity -60 to +10dBu
Pad in Sensitivity -40 to +10dBu
Pad out 2k ohm
Pad in >10k ohm, -20dB
Max input level +30dBu
XLR phantom power +48V, on/off
Ext Input TRS unbalanced >5k ohm, 0dBu
Inserts Channel TRS, tip send, ring return, 0dBu
Output TRS, tip send, ring return, -2dBu
Mix outputs XLR balanced pin 2 hot <75 ohm, +4dBu, +26dBu max
Monitor output TRS impedance balanced <75 ohm, -2dBu, +21dBu max
XLR balanced pin 2 hot <75 ohm, +4dBu, +26dBu max
Headphones TRS, tip L, ring R, 30 to 600 ohm headphones recommended
Lamp 4-pin XLR max 12V 5W lamp