SoundCraft MH3 User manual

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MH3 User Guide Preliminary Issue
MH3 User GuideMH3 User Guide
MH3 User GuideMH3 User Guide
MH3 User Guide

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© Harman International Industries Ltd. 2003
All rights reserved
Parts of the design of this product may be protected by worldwide patents.
Part No. ZM0278
Issue: Preliminary 8/1/03
Soundcraft is a trading division of Harman International Industries Ltd. Information in this manual
is subject to change without notice and does not represent a commitment on the part of the
vendor. Soundcraft shall not be liable for any loss or damage whatsoever arising from the use
of information or any error contained in this manual.
No part of this manual may be reproduced, stored in a retrieval system, or transmitted, in any
form or by any means, electronic, electrical, mechanical, optical, chemical, including
photocopying and recording, for any purpose without the express written permission of Soundcraft.
Harman International Industries Limited
Cranborne House
Cranborne Road
POTTERS BAR
Hertfordshire
EN6 3JN
UK
Tel: [phone]
Fax: [phone]
http://www.soundcraft.com
IMPORTANT
Please read this manual carefully before using
your mixer for the first time.

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MH3 User Guide Preliminary Issue
IntrIntr
IntrIntr
Introductionoduction
oductionoduction
oduction

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Key FeaturKey Featur
Key FeaturKey Featur
Key Featureses
eses
es
· Versatile design allows FOH, Monitors, or Monitors from FOH
· Semi-modular for flexible layouts and easy serviceability
· Frame sizes 24 mono/4 stereo, 32 mono/4 stereo, 40 mono/4 stereo, 48 mono/4
stereo, 56 mono/4 stereo
· Flexible Auxiliary Bus structure with 2 stereo sends for in-ear monitoring
· 8 group busses and 12 aux busses in FOH mode
· 12 monitor busses (8 mono, 2 stereo) in Monitor mode
· Swap mode allows fader control of Aux outputs in Monitor mode
· Integral 12x4 matrix, can be expanded to 12x8 with optional matrix module
· 3-band EQ on FX returns 1-8, can be flipped into output fader path
· New Mic Amp design with high headroom and outstanding CMRR
· New EQ design with focused response
· LCR panning on inputs
· 8 VCA groups and 8 Mute groups with snapshot automation and MIDI control
· Integrated control of BSS Audio Varicurve™ and dbx DriveRack™
· Integral LED bargraph metering for all inputs and outputs
· Optional VU output meterbridge

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WW
WW
Warar
arar
arrantyranty
rantyranty
ranty
1 Soundcraft is a trading division of Harman International Industries Ltd.
End User means the person who first puts the equipment into regular operation.
Dealer means the person other than Soundcraft (if any) from whom the End User
purchased the Equipment, provided such a person is authorised for this purpose by
Soundcraft or its accredited Distributor.
Equipment means the equipment supplied with this manual.
2 If within the period of twelve months from the date of delivery of the Equipment to
the End User it shall prove defective by reason only of faulty materials and/or
workmanship to such an extent that the effectiveness and/or usability thereof is
materially affected the Equipment or the defective component should be returned to
the Dealer or to Soundcraft and subject to the following conditions the Dealer or
Soundcraft will repair or replace the defective components. Any components
replaced will become the property of Soundcraft.
3 Any Equipment or component returned will be at the risk of the End User whilst in
transit (both to and from the Dealer or Soundcraft) and postage must be prepaid.
4 This warranty shall only be available if:
a) the Equipment has been properly installed in accordance with instructions
contained in Soundcraft's manual; and
b) the End User has notified Soundcraft or the Dealer within 14 days of the defect
appearing; and
c) no persons other than authorised representatives of Soundcraft or the Dealer have
effected any replacement of parts maintenance adjustments or repairs to the
Equipment; and
d) the End User has used the Equipment only for such purposes as Soundcraft
recommends, with only such operating supplies as meet Soundcraft's specifications
and otherwise in all respects in accordance Soundcraft's recommendations.
5 Defects arising as a result of the following are not covered by this Warranty: faulty or
negligent handling, chemical or electro-chemical or electrical influences, accidental
damage, Acts of God, neglect, deficiency in electrical power, air-conditioning or
humidity control.
6. The benefit of this Warranty may not be assigned by the End User.
7. End Users who are consumers should note their rights under this Warranty are in
addition to and do not affect any other rights to which they may be entitled against
the seller of the Equipment.

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InstallationInstallation
InstallationInstallation
Installation

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Dimensions and ConfigurationsDimensions and Configurations
Dimensions and ConfigurationsDimensions and Configurations
Dimensions and Configurations

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PrPr
PrPr
Precautions and Safety Instrecautions and Safety Instr
ecautions and Safety Instrecautions and Safety Instr
ecautions and Safety Instructionsuctions
uctionsuctions
uctions
General Precautions
Avoid storing or using the mixing console in conditions of excessive heat or cold, or in positions
where it is likely to be subject to vibration, dust or moisture. Do not use any liquids to clean the
fascia of the unit: a soft dry brush is ideal. Use only water or ethyl alcohol to clean the trim and
scribble strips. Other solvents may cause damage to paint or plastic parts.
Avoid using the console close to strong sources of electromagnetic radiation (e.g. video monitors,
high-power electric cabling): this may cause degradation of the audio quality due to induced
voltages in connecting leads and chassis. For the same reason, always site the power supply
away from the unit.
Caution! In all cases, refer servicing to qualified personnel.
Handling and Transport
The console is supplied in a strong carton. If it is necessary to move it any distance after
installation it is recommended that this packing is used to protect it. Be sure to disconnect all
cabling before moving. If the console is to be regularly moved we recommend that it is installed
in a foam lined flightcase. At all times avoid applying excessive force to any knobs, switches or
connectors.
Power Supplies & Cables
Always use the power supply and cable supplied with the mixer: the use of alternative supplies
may cause damage and voids the warranty; the extension of power cables may result in
malfunction of the mixing console.
W a r n i n g ! Always switch the power supply off before
connecting or disconnecting the mixer power cable, removing
or installing modules, and servicing. In the event of an
electrical storm, or large mains voltage fluctuations,
immediately switch off the PSU and unplug from the mains.
W a r n I n g ! Always ensure that you use the correct PSU
(CPS800) for your mixer.
Signal Levels
It is important to supply the correct input levels to the console, otherwise signal to noise ratio or
distortion performance may be degraded; and in extreme cases, damage to the internal) circuitry
may result. Likewise, on all balanced inputs avoid sources with large common mode DC, AC or
RF voltages, as these will reduce the available signal range on the inputs. Note that OdBu
=0.775V RMS.
Refer to the Specifications section for details of input and output levels.

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Mains InstallationMains Installation
Mains InstallationMains Installation
Mains Installation
General Wiring Procedures
To take full advantage of the excellent signal to noise ratio and low distortion of Soundcraft
consoles, care must be taken to ensure that incorrect installation and wiring does not degrade
the performance of the desk. Hum, buzz, instability and Radio Frequency interference can
usually be traced to earth loops and inferior earthing systems. In some areas, especially heavily
industrial areas, the incoming mains earth will not be adequate and a separate technical earth
for all the audio equipment must be supplied. However, check with your local electricity supply
company to ensure that safety regulations are not infringed or negated.
The successful, hum free, installation of a system requires forethought, and the establishment
of a set of ground rules, which must be consistently adhered to at all stages of installation.
Initial Wiring Considerations
For optimum performance, it is essential for the earthing system to be clean and noise free, as
all signals are referenced to this earth. A central point should be decided on for the main earth
point system, and all earths should be 'star fed' from this point. It is common electrical practice
to `daisy chain' the earths to all electrical outlets but this method is unsuitable for audio
installations. The preferred method is to run an individual earth wire from each outlet, back to
the system star point to provide a safety earth screen reference for each piece of equipment.A
separate earth wire should also be run from each equipment rack and area, to the star point.
This may or may not be used depending on circumstances, but it is easier to install in the first
place, than later when problems arise.The location of the star point should be a convenient,
easily accessible place, preferably at the rear of the console or in the main equipment rack.
Install separate 'clean' and 'dirty' mains outlets, wired individually back to the incoming mains
distribution box. Use the 'clean' supply for all audio equipment and the `dirty' supply for all
lighting, etc. Never mix the two systems.
If necessary, to provide sufficient isolation from mains borne interference, install an isolating
transformer. This should be provided with a Faraday Shield which must be connected with
earth.
Never locate the incoming mains distribution box near audio equipment, especially tape recorders,
which are very sensitive to electro-magnetic fields.
Ensure that all equipment racks are connected to earth, via a separate wire back to the star
point.
Equipment which has unbalanced inputs and outputs may need to be isolated from the rack to
prevent earth loops.
Audio Wiring
Having provided all equipment with power and earthing connections, consideration must be
given to the method of providing audio interconnection and adequate screening of those
interconnections. This must be done in a logical sequence to avoid problems and assist in the
localisation of problem equipment.
Connect the FOH or Monitor system to the console and check for any hum, buzz, or RFI. Only
when you are satisfied with the quietness of the console and the PA system should you proceed
with the next step.
Connect stereo or multitracktape recorders, FX and foldback sends one at a time, checking and
isolating any connection which degrades performance.
Connect all other peripheral devices.
Connect all microphone lines.

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By following this sequence much time and future trouble will be saved, and the result will be a
quiet, stable system.
Shielding
Audio equipment is supplied with a variety of input and output configurations, which must be
taken into consideration when deciding where the screen connections should be made. There
are three sources of unwanted signal being impressed on the screen, which are as follows:
Extraneous electrostatic or electromagnetic fields.
Noise and interference on the earth line.
Capacitive coupling between the screen and signal wires.
To minimise the adverse affects of the unwanted coupling to the signal wires, it is important
that the screen is connected at one end only, i.e. the screen must not carry any signal) current.
Any signal) on the wires within the screen will be capacitively coupled to the screen. This
current will ultimately be returned to the source of the signal, either directly, if the screen is
connected at the signal source end, or indirectly via the earthing system, if the signal is connected
at the signal destination end. The indirect connection will cause an increase in high frequency
cross-talk, and should be avoided wherever possible.
Therefore, in general, always connect the shield only at the signal source end. In high RF areas,
the screen can also be connected to earth via a 0.01 mF capacitor. This will present a short
circuit at RF frequencies, thus lowering the effective shield impedance to ground. However, at
low audio frequencies the reactance of the capacitor will be sufficiently high not to cause an
earth loop problem.
Points to Remember
In all cases, use good quality twin screened audio cable. Check for instability at the output.
Always connect both conductors at both ends, and ensure that the screen is only connected at
one end.
Do not disconnect the mains earth from each piece of equipment. This is needed to provide
both safety and screen returns to the system star point.
Equipment which has balanced inputs and outputs may need to be electrically isolated from
the equipment rack and/or other equipment, to avoid earth loops.
It is important to remember that all equipment which is connected to the mains is a potential
source of hum and interference and may radiate both electrostatic or electromagnetic radiation.
In addition, the mains will also act as a carrier for many forms of RF interference generated by
electric motors, air-conditioning units, thyristor light dimmers etc. Unless the earth system is
clean, all attempts to improve hum noise levels will be futile. In extreme cases there will be no
alternative but to provide a completely separate and independent `technical earth' to replace
the incoming 'noisy earth'. However, always consult your local electricity supply authority to
ensure that safety regulations are not being infringed.

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ConnectionsConnections
ConnectionsConnections
Connections

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BLOCK DIAGRAMSBLOCK DIAGRAMS
BLOCK DIAGRAMSBLOCK DIAGRAMS
BLOCK DIAGRAMS

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Mono Input ModuleMono Input Module
Mono Input ModuleMono Input Module
Mono Input Module

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SterSter
SterSter
Stereo Input Moduleeo Input Module
eo Input Moduleeo Input Module
eo Input Module

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GrGr
GrGr
Group/Aux/FX Masteroup/Aux/FX Master
oup/Aux/FX Masteroup/Aux/FX Master
oup/Aux/FX Master

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Aux/Matrix MasterAux/Matrix Master
Aux/Matrix MasterAux/Matrix Master
Aux/Matrix Master

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MonitorMonitor
MonitorMonitor
Monitor

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VCA/CPUVCA/CPU
VCA/CPUVCA/CPU
VCA/CPU

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