SoundCraft LX7-2 User manual

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TT
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Technical Manualechnical Manual
echnical Manualechnical Manual
echnical Manual

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© Harman International Industries Ltd. 2004
All rights reserved
Parts of the design of this product may be protected by worldwide patents.
Part No. ZM0289-01
Issue: 1
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.

iii
ContentsContents
ContentsContents
Contents
INTRODUCTIONINTRODUCTION
INTRODUCTIONINTRODUCTION
INTRODUCTION 1 - 11 - 1
1 - 11 - 1
1 - 1
FeaturFeatur
FeaturFeatur
Featureses
eses
es 1 - 21 - 2
1 - 21 - 2
1 - 2
WW
WW
Warar
arar
arrantyranty
rantyranty
ranty 1 - 31 - 3
1 - 31 - 3
1 - 3
SAFETY SYMBOL GUIDESAFETY SYMBOL GUIDE
SAFETY SYMBOL GUIDESAFETY SYMBOL GUIDE
SAFETY SYMBOL GUIDE 1 - 51 - 5
1 - 51 - 5
1 - 5
INSTINST
INSTINST
INSTALLAALLA
ALLAALLA
ALLATIONTION
TIONTION
TION 1 - 51 - 5
1 - 51 - 5
1 - 5
IMPORIMPOR
IMPORIMPOR
IMPORTT
TT
TANT SAFETY WANT SAFETY W
ANT SAFETY WANT SAFETY W
ANT SAFETY WARNINGSARNINGS
ARNINGSARNINGS
ARNINGS 1 - 61 - 6
1 - 61 - 6
1 - 6
WARNINGS 1 - 7
General Precautions 1 - 8
Handling and Transport 1 - 8
Power Cable 1 - 8
Signal Levels 1 - 8
Mains InstallationMains Installation
Mains InstallationMains Installation
Mains Installation 1 - 81 - 8
1 - 81 - 8
1 - 8
General Wiring Procedures 1 - 8
Initial Wiring Considerations 1 - 9
Audio Wiring 1 - 9
Shielding 1 - 9
Points to Remember 1 - 10
WORKING SAFELWORKING SAFEL
WORKING SAFELWORKING SAFEL
WORKING SAFELY WITH SOUNDY WITH SOUND
Y WITH SOUNDY WITH SOUND
Y WITH SOUND 1 - 101 - 10
1 - 101 - 10
1 - 10
Setting Up & TSetting Up & T
Setting Up & TSetting Up & T
Setting Up & Trr
rr
roubleshootingoubleshooting
oubleshootingoubleshooting
oubleshooting 1 - 101 - 10
1 - 101 - 10
1 - 10
Initial set-up 1 - 10
Troubleshooting 1 - 10
Connecting LeadsConnecting Leads
Connecting LeadsConnecting Leads
Connecting Leads 1 - 131 - 13
1 - 131 - 13
1 - 13
Audio Connector PinoutsAudio Connector Pinouts
Audio Connector PinoutsAudio Connector Pinouts
Audio Connector Pinouts 1 - 141 - 14
1 - 141 - 14
1 - 14
DimensionsDimensions
DimensionsDimensions
Dimensions 1 - 151 - 15
1 - 151 - 15
1 - 15
BLOCK DIAGRAMBLOCK DIAGRAM
BLOCK DIAGRAMBLOCK DIAGRAM
BLOCK DIAGRAM 1 - 161 - 16
1 - 161 - 16
1 - 16
USING THE CONSOLEUSING THE CONSOLE
USING THE CONSOLEUSING THE CONSOLE
USING THE CONSOLE 1 - 181 - 18
1 - 181 - 18
1 - 18
Overview 1 - 19
Mono Input Channel 1 - 20
Stereo Input Channel 1 - 24
Master Section 1 - 25
Mark-up Sheet 1 - 27
TYPICAL SPECIFICATYPICAL SPECIFICA
TYPICAL SPECIFICATYPICAL SPECIFICA
TYPICAL SPECIFICATIONSTIONS
TIONSTIONS
TIONS 1 - 281 - 28
1 - 281 - 28
1 - 28
CIRCUIT DIAGRAMSCIRCUIT DIAGRAMS
CIRCUIT DIAGRAMSCIRCUIT DIAGRAMS
CIRCUIT DIAGRAMS 2 - 12 - 1
2 - 12 - 1
2 - 1
PP
PP
PARAR
ARAR
ARTS LISTTS LIST
TS LISTTS LIST
TS LIST 3 - 13 - 1
3 - 13 - 1
3 - 1

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NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the
FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This
equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions,
may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined
by turning the equipment off and on, the user is encouraged to try to correct the interference by one or
more of the following measures:
— Reorient or relocate the receiving antenna.
— Increase the separation between the equipment and receiver.
— Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
— Consult the dealer or an experienced radio/TV technician for help.
This Class A digital apparatus meets the requirements of the Canadian Interference-Causing Equipment Regulations.
Cet appareil numérique de la Classe A respecte toutes les exigences du Règlement sur le matériel brouilleur du Canada.

1 - 1
INTRODUCTION

1 - 2
Features
The LX7-II combines the essential Soundcraft live mixer qualities with basic recording-oriented features, in a compact frame that s
light enough for one person to carry yet easy to configure and use. This makes it especially suitable for multi-purpose use in venues
such as small halls and community centres, while its direct channel outputs make the LX7-II an ideal choice for bands who need
a live desk that can double up in the studio.
Housed in a choice of 16, 24 or 32 channel frame, LX7-II provides 24, 32 or 40 inputs - with no less than 13 separate bus outputs
including mix, 4 groups, a dedicated mono bus for centre speaker clusters, side or rear fills, and six auxiliary busses.
There are also 8, 16 or 24 direct outs, depending on the frame size of your console.
LX7-II s balanced mic inputs all use Soundcraft new GB30 padless mic preamp providing 60dB of gain and 22dBu of headroom.
Each input also includes 4 band EQ with two swept mid frequency controls. In addition, EQ In/Out switch and steep 18dB/Octave
High Pass Filter, allow effective audio control in difficult venues whilst the six auxiliary sends are pre-post switchable in pairs from
each channel, providing a maximum of 4 pre-fader and six post-fader. This makes LX7-II equally applicable for foldback - heavy
performance or in situations where more effects are required.
LX7-II groups section houses two further stereo inputs - with EQ, auxiliaries for keyboards or stereo recording devices - as well as
two FX returns. All four groups are routable to mix and include 12 segment bargraph metering for accurate monitoring and inserts.
Six auxiliary masters on rotary controls also included AFL soloing.
In the master section there is talkback provision to all pre-fade auxiliaries and the mix. Phantom power in banks of four, and a two
track return for pre-show music are also present. A two-track to mix switch allows the engineer to play CD s over the main PA
whilst back-stage set-up is going on, with one press of a button. The mix is also routable to the separate mono bus if mono PAs are
required.
LX7-II is built in a rugged wedge-shaped steel chassis with an internal power supply, professional all-metal jackfield and connectors
on the rear of the console. All inputs and outputs are balanced.
Applications incluse : Gigging Bands, Small installations, Small venues, Theatres, Houses of Worship and Live & studio recording.

1 - 3
Warranty
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 appear-
ing; 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 recom-
mends, 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.

1 - 4

1 - 5
INSTALLATION
Foryourownsafetyandto
avoidinvalidationofthe
warrantypleasereadthis
sectioncarefully.
SAFETYSYMBOLGUIDE
For your own safety and to avoid invalidation of the warranty all text marked with these symbols should be read carefully.
CAUTIONS
The lightning flash with arrowhead symbol, is intended to alert the user to
the presence of un-insulated dangerous voltage within the products
enclosure that may be of sufficient magnitude to constitute a risk of
electric shock to persons.
WARNINGS
The exclamation point within an e uilateral triangle is intended to alert the
user to the presence of important operating and maintenance (servicing)
instructions in the literature accompanying the appliance.
NOT S
Contain important information and useful tips on the operation of your
e uipment.
H ADPHON SSAF TYWARNING
Contain important information and useful tips on headphone outputs and
monitoring levels.

1 - 6
IMPORTANTSAFETYWARNINGS
THISUNITMUSTB  ARTH D
Undernocircumstancesshouldthemainsearthbedisconnectedfromthe
mainslead.
The wires in the mains lead are coloured in accordance with the following code:
Earth: Green and Yellow (Green/Yellow - US)
Neutral: Blue (White - US)
Live: Brown (Black - US)
As the colours of the wires in the mains lead may not correspond with the coloured markings identifying the terminals in your plug,
proceed as follows:
The wire which is coloured Green and Yellow must be connected to the terminal in the plug which is marked with the letter
E or by the earth symbol.
The wire which is coloured Blue must be connected to the terminal in the plug which is marked with the letter N.
The wire which is coloured Brown must be connected to the terminal in the plug which is marked with the letter L.
Ensure that these colour codings are followed carefully in the event of the plug being changed.
Toavoidtheriskoffire,replacethemainsfuseonlywiththecorrectvalue
fuse,asmarkedontherearpanel.
Theinternalpowersupplyunitcontainsnouserserviceableparts.Refer
allservicingtoaqualifiedserviceengineer,throughtheappropriate
Soundcraftdealer.

1 - 7
WARNINGS
 Read these instructions.
 Keep these instructions.
 Heed all warnings.
 Follow all instructions.
 This unit contains no user serviceable parts. Refer all servicing to a qualified service
engineer, through the appropriate Soundcraft dealer.
 Clean the apparatus only with a dry cloth.
 Do not install near any heat sources such as radiators, heat resistors, stoves, or other
apparatus (including amplifiers) that produce heat.
 Do not use this apparatus near water. The apparatus must not be exposed to dripping or
splashing. Objects containing liquid must not be placed on the apparatus.
 The disconnect device is the mains plug; it must remain accessible so as to be readily
operable in use.
 Do not defeat the safety purpose of the polarized or grounding type plug. A polarized
plug has two blades with one wider than the other. A grounding type plug has two
blades and a third grounding prong. The wide blade or the third prong are provided for
your safety. When the provided plug does not fit into your outlet, consult an electrician
for replacement of the obsolete outlet.
 Protect the power cord from being walked on or pinched particularly at plugs, convenience
receptacles and the point where they exit from the apparatus.
 Only use cables and hardware specified by the manufacturer.
 Unplug this apparatus during lightning storms or when unused for long periods of time.
 Refer all servicing to qualified service personnel. Servicing is required when the apparatus
has been damaged in any way such as power-supply cord or plug is damaged, liquid
has been spilled or objects have fallen into the apparatus, the apparatus has been
exposed to rain or moisture, does not operate normally or has been dropped.
 It is recommended that all maintenance and service on the product should be carried
out by Soundcraft or its authorised agents. Soundcraft cannot accept any liability
whatsoever for any loss or damage caused by service, maintenance or repair by
unauthorised personnel.
 If a trolley is used to carry multiple , use caution when moving the trolley / apparatus
combination to avoid injury from tip-over.
 The ventilation openings should not be impeded by covering with any items, such as
newspapers, tablecloths, curtains etc.
 No naked flame sources, such as lighted candles or cigarettes etc., should be placed on
the apparatus.

1 - 8
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 cloth is ideal.
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.
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Cable
Always use the power supply cable supplied with the mixer: the use of alternative cables may cause damage and voids the
warranty.
Warning!Intheeventofanelectricalstorm,orlargemainsvoltage
fluctuations,immediatelyswitchoffthemixerandunplugfromthemains.
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.
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.

1 - 9
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.
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.

1 - 10
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.
WORKINGSAFELYWITHSOUND
Although your new console will not make any noise until you feed it signals, it has the capability to produce sounds which when
monitored through an amplifier or headphones can damage hearing over time.
The table below is taken from the Occupational Safety & Health Administration directive on Occupational noise exposure (1926.52):
PERMISSABLE NOISE EXPOSURE
DURATION PER DAY, HOURS SOUND LEVEL dBA SLOW RESPONSE
890
692
495
397
2 100
1.5 102
1 105
0.5 110
<0.25 115
Conforming to this directive will minimise the risk of hearing damage caused by long listening periods. A simple rule to follow is the
longer you listen the lower the average volume should be.
Please take care when working with your audio - if you are manipulating controls which you don t understand (which we all do when
we are learning), make sure your monitors are turned down. Remember that your ears are the most important tool of your trade,
look after them, and they will look after you.
Most importantly - don t be afraid to experiment to find out how each parameter affects the sound - this will extend your creativity
and help you to get the best results.

1 - 11
Settin Up&Troubleshootin
Initialset-up
Once you have connected up your system (see the sections on connection and wiring earlier in this manual for guidance) you are
ready to set initial positions for the controls on your mixer.
Set up individual input channel as follows:
Connect your sources (microphone, keyboard etc.) to the required inputs and release the MUTE switches. Note: Phantom
powered mics should be connected before the 48V is switched on.
Set Master faders at 0, input faders at 0, route the channels to MIX and set power amplifier level to suit the application.
Provide a typical performance level signal and press the PFL button on the first channel, monitoring the level on the
bargraph meters.
Adjust the input gain until the meter display is in the amber section, with occasional peaks to the first red LED at a typical
maximum source level. This allows sufficient headroom to accommodate peaks and establishes the maximum level for normal
operation (but see note below).
Repeat this procedure on other channels as required.
Listen carefully for the characteristic sound of `feedback . If you cannot achieve satisfactory input level setting without
feedback, check microphone and speaker placement and repeat the exercise. If feedback persists, it may be necessary to use
a Graphic Equaliser to reduce the system response at particular resonant frequencies.
Note: The initial settings should only be regarded as a starting point for your mix. It is important to remember that many factors
affect the sound during a live performance, for instance the channel EQ settings or even the size of the audience!
You are now ready to start building the mix and this should be done progressively, listening carefully for each component in the mix
and watching the meters for any hint of overload. If this occurs, back off the appropriate Channel Fader slightly until the level is out
of the red segments, or adjust the Mix Master Faders. This procedure will ensure that the mixer is set up correctly, with adequate
headroom. If more amplification is needed, adjust the power amplifier level controls.
Troubleshooting
No Power
Is the mains supply present?
Is the mains lead firmly connected?
Check the mains fusing
If only one of the power indicators is illuminated, consult your Soundcraft dealer
Condenser Mic Not Working
Is the 48V turned on?
Is the mic plugged into the Mic input?
Is the mic cable a balanced 3-wire type?

1 - 12
Meters not showing any signal
Has the input gain been set correctly? (see above.)
Is the source connected to the appropriate input socket for the level of signal?
Do you have something connecetd on the Inserts, and is that external device switched on?
Are the Master faders set at max., are input faders set high enough and is the channel routed to the output being monitored?
Is the MUTE switch released on the relevant channels?
Is the appropriate monitor select switch pressed?
Is there a PFL/AFL pressed on another channel?
No Mix output
Check that the Mix Master Fader is up?
Check that the 2TK REPLACES MIX switch is released?
No Monitor output
Is a headphone jack plugged in?
Is the Monitor + Phones control set high enough?
Is the appropriate monitor select switch pressed?
Headphones Distorting
Are the headphones less than 200W impedance?
Is the Monitor + Phones level set too high?

1 - 13
Balanced Unbalanced Insert Leads
’Y’ Leads (Unbalanced) ’Y’ Leads (Balanced) Headphone Splitter
Connectin Leads

1 - 14
AudioConnectorPinouts

1 - 15
Dimensions

1 - 16
BLOCKDIAGRAM