SoundCraft Spirit Live 4 User manual

User Guide
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Basic Principles of PA Mixing . . . . . . . . . . . . . . . . . 3
Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . 6
Connections and Connectors . . . . . . . . . . . . . . . 6
Fault Finding Guide . . . . . . . . . . . . . . . . . . . . 9
Getting to know your console . . . . . . . . . . . . . . . . 10
Facilities . . . . . . . . . . . . . . . . . . . . . . . . . 10
Input Channel . . . . . . . . . . . . . . . . . . . . . . 10
Stereo Sections . . . . . . . . . . . . . . . . . . . . . . 15
Group Sections . . . . . . . . . . . . . . . . . . . . . . 17
Master Section . . . . . . . . . . . . . . . . . . . . . . 18
Using yourSPIRIT LIVE 4 Console . . . . . . . . . . . . . 20
Initial Set Up . . . . . . . . . . . . . . . . . . . . . . . 20
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Public Address . . . . . . . . . . . . . . . . . . . . . . 22
Recording . . . . . . . . . . . . . . . . . . . . . . . . . 24
Care of yourmixer . . . . . . . . . . . . . . . . . . . . . . 25
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Selectable Options . . . . . . . . . . . . . . . . . . . . . . 27
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 29
Front Panel Layout . . . . . . . . . . . . . fold out rearcover
Block Diagram . . . . . . . . . . . . . . . . . inside rear cover
Page 1

IN TRO DUC TIO N
Congratulations on your purchase of a SPIRIT LIVE 4 mixer.
Owning a Soundcraft console brings you the expertise and
support of one of the industry’s leading manufacturers and
the results of over 20 years experience supporting some of the
biggest names in the business.
Designed by engineers who understand the individual needs
of musicians, SPIRIT LIVE 4 has been built to the highest
standards using quality Japanese components and employing
automated assembly techniques beyond the reach of most
manufacturers of compact mixers.
A rugged steel chassis is combined with moulded side trims
to give protection and distinctive appearance. Custom
moulded controls, designed for the best ‘feel’ and visual
clarity complement the styling, resulting in a truly
professional product which is ideal for both touring and fixed
PA installations.
SPIRIT LIVE 4 is available in 12, 16, 24 and 32 channel frame
sizes, and the 12 and 16 channel sizes may be extended by
adding an 8 channel Expander. The Expander can be attached
quickly and securely to the console, requiring only a
screwdriver to complete the installation.
SPIRIT LIVE 4 incorporates circuit technology identical to
that used on some of the most sophisticated Soundcraft
consoles. The input channels are able to accept a wide range
of Microphone and Line level signals from separate input
sockets. Every channel features wide range gain control and
Line input pad, 3-band Equalisation with swept Mid and LF
range, plus a Hi-Pass Filter, 5 Auxiliary Sends, PFL(Pre Fade
Listen), Peak LED, Panning to a Stereo Bus and routing in
pairs to four Output Groups. Each channel has a separate
Direct Output and is controlled by a high-quality long throw
fader.
All frame sizes are provided as standard with dedicated
stereo inputs, arranged in pairs. One pair is included on the
12 channel frame and two pairs on all other frame sizes. Each
stereo input includes a 2-band EQ and a single auxiliary send
control with switching which allows prefade or postfade
sourcing with access to three of the five Auxiliary busses. The
stereo channel signal may be routed to either the Mix output
or to Groups 1 & 2 (upper) or Groups 3 & 4 (lower).
Page 2

BASIC PRINCIPLES OF PA MIXING
There was a time when the P.A. system and the operator
existed only to increase the overall volume of the performers,
so that they could be heard in a large room or above high
ambient noise levels. This just isn’t true any more. The sound
system and the sound engineer have become an integral part
of the performance, and the artists are heavily dependent on
the operator’s skill and the quality of the equipment.
The following introduction to the basics of mixing are
included for the benefit of those users who may not have any
significant familiarity with sound equipment, and who are
baffled by the endless jargon used by engineers and artists
alike.
The four Output Groups provide submixing to the Mix L/ R
outputs or may feed external equipment directly. Each
incorporates stereo panning and PFL monitoring or bargraph
metering and includes an external Return input for effects or
submixing from external sources.
The Master section provides master level control for the Left,
Right, Mono and Auxiliary Send busses, with separate AFL
monitoring on each Auxiliary Send and the Mono output.
The Mix L/ R and Group outputs all have insert points for the
connection of external signal processing.
Comprehensive Talkback facilities are provided, which allow
an external talkback microphone to be routed to Mix L/ R,
Groups and Auxes 1 & 2 as required. Six 12-segment, 3-colour
peak reading LED bargraph meters provide clear display of
Mix L/ R, Group and PFL signals. Pressing any PFL or AFL
switch puts the selected signal onto both sides of the
headphones output, and the right bargraph meter.
SPIRIT Live 4 is designed to be as user-friendly as possible,
but a few minutes spent reading through this manual will
help you become familiar with the product away from the
pressure of a live session, and allow you to gain full benefit
from the superb performance offered by your new mixer.
Above all, remember that your SPIRIT mixer is designed to
extend your creativity. The more you explore the controls
and the effect they have on the sound output, the more you
will appreciate how you can influence and enhance the final
sound.
Page 3

Th e M ix e r As one would expect, the main purpose of the mixer is to
combine sounds, but under precise and smooth control. This
is why long-throw faders are essential on any professional
product. The faders provide you with clear and instinctive
control of the final sound balance and like an artist playing an
instrument you should listen to the effect of your fader
movements, not look at your hands.
Your SPIRIT LIVE 4 mixer accepts a wide range of input
signals via a microphone input, for very low level signals, or a
line input, for higher level signals from, for instance, tape
machines, effects processors, etc.
The mixer is split into two sections. The Inputs receive, match
and process individual source signals, and distribute them at
precise mix levels to either a stereo Mix output or to one of
the Groups. The Master section allows overall level control
of all outputs, and provides monitoring of the audio signal at
many points in the mixer, either on headphones or meters.
The Equaliser controls are the most flexible and potentially
destructive feature of the mixer. They have a similar effect on
the frequency response of the input channel as the tone
controls on a hi-fi system, but with much greater precision,
and allow particular characteristics of the input signal to be
emphasised or reduced. It is very important that you become
familiar with the effect each control has on the sound and this
is best achieved by spending time listening to the effect of each
control on a well-known track played through the mixer.
The Auxiliary Sends provide a way of routing the input
signals to a number of secondary outputs, for artists foldback,
echo units or additional speaker outputs.
The Pan control adjusts the position of the input signal within
the stereo mix, and can be swept from full left, through to full
right. This allows particular artists to retain their correct
spatial position within the mix, and can be valuable for live
effects.
Pre-Fade-Listen(PFL) allows you to monitor the signal at
many points in the mixer. Pressing any PFL switch places the
signal at that particular point onto the headphones and the
right meter, to check the quality of the signal or to pin-point
problems. Using PFL will not affect the signals on the outputs
from the desk.
Page 4

Each input channel and the three main outputs have an Insert
‘A’ gauge jack socket, which is a break point in the signal
path. It allows the signal to be taken out of the mixer,
through an external piece of equipment and then back into the
mixer directly after its original exit point. The Insert point is
normally bypassed by the ‘A’ gauge jack socket contacts, and
is only brought into operation when a plug is inserted.
Typical uses would include Effects Processors, Limiters,
additional Equalisers or Delay units. In addition, each
channel has a Direct output which may also be used to feed
external equipment.
The terms PRE and POST are often used in the context of
Inserts, Equalisers and Auxiliary Sends, and describe whether
that facility is placed before (Pre) or after (Post) another
particular section. This is explained further in the detailed
description of facilities.
A mixer is often judged, amongst other factors, by the amount
of Headroom available. This is a measure of the reserve
available to cope with sudden peaks in the input signal,
without distortion caused by Clipping, when the signal
becomes so high that it would exceed the power supply rail
voltages and is as a result limited. This commonly occurs
where gain settings are incorrectly set or where sources are
improperly matched to the mixer input. If the source signal is
too high, clipping and distortion results. If the signal is too
low it becomes masked by the background noise which is
present to some degree in all mixers. The diagram below
illustrates this point.
If the signal level is too low it may be masked
by the noise.
Signal
Noise
If the signal level is too high, clipping distortion
may occur.
Clipped
Signal
Noise
Page 5

GETTING STARTED
CONNECTIONSAND
CONNECTORS
Although this may seem a simple subject, faulty connectors and
cabling are the source of most sound system problems.
Correctly-made cables of the proper type, with the right
connectors for the job will ensure peak performance from
your system with minimum noise pick-up. The following
section will help you to connect SPIRIT LIVE 4 correctly.
Two different types of audio connectors are used, 3-pin XLR
and 1⁄4" three pole (‘A’ gauge) jacks. These are used in several
configurations as shown in the diagrams below.
Balanced
Input
2. Hot(+ve)
3. Cold(-ve) 1. Screen
Unbalanced
Input
1. Screen
2. Hot(+ve)
Link 3
to 1
Unbalanced
Output
1. Screen 2. Hot(+ve)
Link 3
to 1
3 POLE (stereo) JACK 2 POLE (mono) JACK
Tip
Ring
Sleeve
Send
Return
Screen
Left Signal
Right Signal
Ground
Signal
Ground
Tip
Ring Sleeve
Hot(+ve)
Cold(-ve)
Screen
Headphones Unbalanced
Output
(see text)
Line Input
Aux Outputs
FX Returns
Direct Outputs
Insert Points
Page 6

Ba la nc e d a nd
Unbala nced
All channel inputs are balanced, i.e. there are separate
+ve(hot) and -ve (cold) wires for each signal plus a ground.
The design of the differential input amplifiers is such that
interference picked up on these wires is cancelled out. This is
because, since both wires are in close proximity, the same
interference will be picked up on each wire and balanced
input amplifiers will only amplify the difference between
+ve(hot) and -ve(cold). Any signal on both hot and cold (i.e.
noise) will not be amplified - this is known as common mode
rejection (CMR). Balanced inputs should always have both
+ve and -ve connected or if only an unbalanced source, the
-ve pin shorted to ground.
Note: many modern audio/ musical instruments have
electronically balanced outputs which should not be
unbalanced by shorting one wire to ground. Always use your
inputs balanced where possible.
The Mix L/ R and Mono outputs, Group and Auxiliary
outputs are ground compensated and provide a very effective
way of optimising noise immunity, without the cost and
complexity of balanced outputs. These outputs employ
ground compensation techniques to cancel out the effects of
variation in ground potential between the mixer and other
equipment which would otherwise show up as hum. If the
output is driving a device or amplifier that has an unbalanced
input, connect the -ve(cold) signal to the ground at the
destination, not at the output of your SPIRIT LIVE 4 console.
Pola rity You will probably be familiar with the concept of polarity in
electrical signals and this is of particular importance to
balanced audio signals. Just as a balanced signal is highly
effective at cancelling out unwanted interference, so two
microphones picking up the same signal can cancel out, or
cause serious degradation of the signal if one of the cables has
the +ve and -ve wires reversed. This phase reversal can be a
real problem when microphones are close together and you
should therefore take care always to connect pins correctly
when wiring audio cables.
Grounding and Shielding For optimum performance it is vital that all signals are
referenced to a solid, noise-free earthing point and that all
signal cables have their screens connected to ground. To
avoid earth ‘loops’, use balanced connections where possible
and ensure that all cable screens and other signal earths are
connected to ground only at their source and not at both ends.
Page 7

If the use of unbalanced connections is unavoidable, you can
mimimise noise by following these wiring guidelines:
•On INPUTS,unbalance at the source and use a twin,
screened cable as though it were balanced. (see below)
•On OUTPUTS, connect the signal to the +ve output pin,
and the ground of the output device to -ve. If a twin
screened cable is used, connect the screen only at the mixer
end. (see below)
+
+
+
+
-
-
Mixer
Mixer
Source
Device
Output
Device
GND
GND
GND
INPUT
OUTPUT
+
+
+
+
-
-
-
-
Ground loop
through screen
and chassis
Mixer
Mixer
Source
Device
Source
Device
GND
UNBALANCED
BALANCED INPUT
✗
✓
Avoid running audio cables or placing audio equipment,
close to thyristor dimmer units or power cables.
Noise immunity is improved significantly by the use of low
impedance sources, such as good quality professional
microphones or the outputs from most modern audio
equipment. Avoid cheaper high impedance microphones,
which may suffer from interference over long cable runs, even
with well-madecables.
Page 8

Fault Finding Guide Repairing a sound mixing console requires specialist skills, but
basic Fault Finding is within the scope of any user if a few
basic rules are followed.
•Get to know the Block Diagram of your console (see inside
rear cover)
•Get to know what each component in the system is
supposed to do.
•Learn where to look for common trouble spots.
The Block Diagram (see inside rear cover) is a representative
sketch of all the components of the console, showing how
they connect together and how the signal flows through the
system. Once you have become familiar with the various
component blocks you will find the Block Diagram quite easy
to follow and you will have gained a valuable understanding
of the internal structure of the console.
Each Component has a specific function and only by getting
to know what each part is supposed to do will you be able to
tell if there is a genuine fault! Many ‘faults’ are the result of
incorrect connection or control settings which may have been
overlooked.
Basic Troubleshooting is a process of applying logical
thought to the signal path through the console and tracking
down the problem by elimination.
•Swap input connections to check that the source is really
present. Check both Mic and Line inputs.
•Eliminate sections of the channel by using the insert point
to re-route the signal to other inputs that are known to be
working.
•Route channels to different outputs or to auxiliary sends to
identify problems on the Master section.
•Compare a suspect channelwith an adjacent channel
which has been set up identically. Use PFL and AFL to
monitor the signal in each section.
Page 9

GETTING TO KNOWYOURCONSOLE
Refer to the fold-out front panel diagram which shows the
control functions on the SPIRIT LIVE 4. Each facility is
described below, and is identified by the reference number.
FACILITIES
INPUTCHANNEL
1. MICROPHONE INPUT
The Microphone input is via a standard female XLR-3
connector and is available when the LINE -20dB switch is
released. It is designed to accept a wide range of balanced or
unbalanced low impedance input signals.
+48V Phantom Power is available on each input microphone
socket. This is switched on globally from the power supply in
the case of the 12, 16 and 24 channel desks, or from a rocker
switch adjacent to the d.c. power connector at the top right of
the 32 channel desk. Should you wish to configure inputs
without +48V power, see Selectable Options on Page 27 for
details of this modification.
Transformer-coupled dynamic microphones may be used
without causing damage, even when the +48V power is
connected, but care must be taken when using unbalanced
sources, because of the voltage present on pins 2 and 3 of the
XLR connector. Microphone input level is set by the GAIN
control(6).
NOTE: Phantom powered mics should not be plugged in
with the +48V switched on. Also you should be aware that
some microphones draw an unusually large current which
may overload the power supply, resulting in distortion.
Consult your microphone supplier for guidance if necessary.
2. DIRECTOUTPUT
A ground compensated DIRECToutput is provided, fed from
the output of the fader buffer, which is therefore unaffected
by the position of the ROUTING switches or PAN control.
This provides an ideal source for external processing units,
the output of which may be brought back to the console
through the STEREO sections or group RETURNS, or to
directly send to the tracks of a tape machine for multitrack
recording. This provides as many Tape Sends as there are
mixer channels, without using the group or mix outputs.
INPUT
Page 10

3. LINE INPUT
The LINE Input is a 3-pole 1⁄4"‘A’ gauge jack socket, to accept
balanced or unbalanced line level sources when the LINE
switch(5) is pressed. Unlike the low impedance Microphone
input, this stage presents a high impedance(>10kΩ) to the
input signal, enabling many types of instruments to be
plugged straight in without D.I. boxes or external
preamplifiers.
Line inputs will be found useful as extra Effects Returns,
where additional post-effect equalisation is required.
4. INSERT
The INSERT is a break point in the input channel signal path.
It allows the signal to be taken out of the mixer, through an
external piece of equipment and then back into the mixer to
continue through to the final output. The Insert is a 3-pole 1⁄4"
‘A’ gauge Jack Socket, which is normally by-passed. When a
jack plug is inserted, the signal path is broken at a point just
after the Hi-Pass Filter, but before the EQ section. The signal
from the channel appears on the TIP of the plug and is
returned on the RING. The insert point allows limiters,
compressors and other signal processing units to be added as
required to particular input channels and because it is located
PRE EQ, noise generated by the external equipment may be
reduced by a small amount of H.F. cut in the Equaliser.
5. LINE SELEC T
The LINE switch selects Line input when pressed, and
Microphone input when released. When Line is selected the
Gain range is reduced by 20dB (see 6 below).
6. GAIN CONTROL
When the Microphone input is selected this control acts as a
SENSITIVITY control covering a 50dBrange. Channel signal
level increases as the control is turned clockwise. When the
Line input is selected it serves as a GAIN control, with the
scaling reduced by -20dB from the printed scale. A nominal
0dB input signal will pass through at unity gain, with the
knob set at the 20dB position. Some audio equipment,
particularly that intended for domestic use, operates at a
nominal -10dBV level and an increased Gain setting will be
required.
INPUT
Page 11

7. HI- PASS FILTER
Pressing this switch inserts a 12dB per octave 100Hz Hi-Pass
Filter in the signal path, immediately after the input amplifier.
This is particularly useful on live vocals, and its use is
strongly recommended, even on male vocals. It can also be
used for filtering out low frequency hum.
8. EQ UALISER
The Equaliser(EQ) comprises three sections. The upper
control provides H.F.(treble) boost and cut of +/ -15dB. The
lower two pairs of knobs are arranged as a cut/ boost control
(lower knob) of +/ - 15dB, and a SWEEP(frequency) control
which determines at which frequency the boost/ cut action
will be centered. The LF sections are essentially Swept Low
Frequency controls, covering a range from 40 to 400Hz and
providing much greater flexibility than a conventional
LF(bass) control. The MID section, with a frequency range
from 250Hz to 8kHz is particularly versatile for vocals,
enabling particular characteristics of the singer to be lifted or
suppressed very precisely.
4.0
3.0
2.0
1.0
0.0
-1.0
-2.0
-3.0
-4.0
20 100 1k 10k 20k
dB
Frequency/Hz
HI-Pass Filter
20.0
15.0
10.0
5.0
0.0
-5.0
-10.0
-15.0
-20.0
20 1k 10k 20k
100
dB
Frequency/Hz
LF Section
Frequency Response Curvesof the Hi-PassFilter
Frequency Response Curvesof the Equaliser
INPUT
Page 12

9. AUXILIARY SENDS
These controls route the input channel signal to any one or
more Auxiliary busses. These are separate from the main
outputs and can therefore provide additional outputs for
foldback, echo units or extra loudspeaker ‘fills’.
AUX 1 & 2 are derived before the channel fader(PRE FADE),
and are therefore unaffected by the fader position. This
makes them particularly suitable for foldback or monitor
feeds, which need to be controlled separately from the main
P.A. mix.
AUX 3, 4 and 5 are derived after the channel fader(POST
FADE), and therefore follow any changes in fader level. They
are normally used to drive effects processing units which are
fed back into the mixer and which must fade out with the
input channel.
AUX 2 may be altered internally to be POST FADE. Refer to
the Selectable Options section (Page 28) for a description of
this modification.
All of the Aux Sends are muted when the ON switch(12) is
released.
20.0
15.0
10.0
5.0
0.0
-5.0
-10.0
-15.0
-20.0
20 1k 10k 20k
100
dB
Frequency/Hz
HF Section
20.0
15.0
10.0
5.0
0.0
-5.0
-10.0
-15.0
-20.0
20 1k 10k 20k
100
dB
Frequency/Hz
MID Section
Frequency Response Curvesof the Equaliser
INPUT
Page 13

10. PAN
The PAN control determines the position of the signal within
the stereo mix image or may be used to route the channel
signal to particular output GROUPS as selected by the
ROUTING SWITCHES (13). Rotation fully anticlockwise
feeds the signal solely to the Left mix buss or Groups 1 and 3,
while rotation clockwise sweeps the image to the right buss or
Groups 2 and 4.
11. PFL/ PEAK LED
When the PFL switch is pressed, the Pre-Fade signal is fed to
the headphones, where it replaces the selected source. The
PFL/AFL LED on the master section illuminates to warn that
the headphones and the meters are now responding to the
PFL/ AFL selection and the PFL LED on the input channel
lights to identify the active channel. This is a useful way of
listening to any required input signal without interrupting the
main mix,for making adjustments or tracing problems.
When the PFL switch is released the LED on the channel
serves as a PEAK indicator, to warn when an excessively high
signal level is present in the channel. The signal is sampled
at two points in the channel, immediately after the input
amplifier (PRE HI-PASS FILTER & PRE INSERT) and POST
EQ. The Peak LED will illuminate approximately 4dB before
clipping and therefore give warning of a possible overload
even if the peaks are removed by external equipment plugged
into the Insert.
12. ON SWITCH
The ON switch enables all outputs from the channel when
pressed, and the associated LED illuminates to show that the
channel is active.
13. ROUTING SWITCHES
The input channel signal may be routed to the main STEREO
MIX (L-R) or pairs of GROUP busses (1-2, 3-4), by pressing
the respective switches. These may be used in conjunction
with the PAN control (10 above) to route the channel signal
proportionately to any of the selected busses.
13. CHANNELFADER
This long-throw fader determines the proportion of the
channel in the mix and provides a clear visual indication of
channel level. Normal operating position is at the ‘0’ mark,
providing 10dB of gain above that point if required.
INPUT
Page 14

STEREO SEC TIO NS
1. STEREO INPUTS
Each Stereo Input section comprises a pair of similar inputs.
The inputs are electronically balanced and separate jacks are
provided for the Left and Right source signals. A mono signal
may be plugged into the upper socket only for each pair to be
fed equally to left and right busses.
2. -10 SWITCH
The input jacks are normally set to match +4dBu nominal
signal levels. Pressing the -10 switch alters the input
sensitivity to match the -10dBV signals from most Hi-Fi
systems or semi-professional tape machines allowing the
inputs to be quickly switched to match, for instance, a cassette
player for pre-show music.
3. EQ UALISATIO N
Each Stereo Input is provided with a 2-band shelving EQ
section giving ±15dB boost & cut at fixed frequencies of 60Hz
and 12kHz.
20.0
15.0
10.0
5.0
0.0
-5.0
-10.0
-15.0
-20.020 1k 10k 20k
100
dB
Frequency/Hz
LF Section
20.0
15.0
10.0
5.0
0.0
-5.0
-10.0
-15.0
-20.020 1k 10k 20k
100
dB
Frequency/Hz
HF Section
Frequency Response Curvesof the Equaliser
STEREO
Page 15

4. AUX SEND
A single control feeds a mono sum of the stereo signal to a
choice of Aux Send busses (see 5 below).
5. AUX SELEC TIO N
The flexibility of the Aux send control (4) is maximised by a
choice of destinations on the two Stereo sections. On the
upper section (Stereo 1) this switch routes the Aux Send to
either AUX 1 (Prefade) when released, or AUX 3 (Postfade)
when pressed. On the lower section the choice is between
AUX 1 (Prefade) when released and AUX 4 (Postfade) when
pressed.
6. BALANCE
The BAL control sets the relative level of the Left and Right
signals. In the centre position its gain is unity. Turning the
control fully clockwise increases the Right signal by +4dB,
and totally kills the Left signal. Full anticlockwise rotation
has the opposite effect. Balance left biases the signal to the
Left buss and Groups 1 & 3, balance right to the Right buss
and Groups 2 & 4.
7. PFL
When the PFL switch is pressed the prefade signal is fed to
the Headphones where it replaces the selected source. The
AFL/PFL LED on the Master Section illuminates to warn that
the headphones and RIGHT/PFL METER are now
responding to the PFL selection and the PFL LED on the
Stereo Section lights to identify the active source.
8. ON
Pressing this switch turns ON the feeds to the Aux Sends and
output busses. The associated LED illuminates to show that
the section is active.
9. ROUTING
A single Routing Switch per section provides access to Mix
L-R and Groups 1-2 or 3-4. The upper section routes between
Mix L-R with the switch released, and Groups 1-2 when
pressed. The lower section routes between Mix L-R with the
switch released and Groups 3-4 when pressed. The relative
levels of the left and right signals is controlled by the
BALance control (6).
STEREO
Page 16

10. FADER
Linear faders are provided for precise and smooth level
control for each Stereo section.
GROUPSECTION
1. RETURN
A mono Return is provided to each output Group, which is
intended for use as a sub-mix from another desk or as an
effects input. The input is electronically balanced on a
standard
1⁄4" 3-pole ‘A’ gauge jack.
2. INSERT
An Insert is provided for each output Group to allow external
processing equipment to be ‘inserted’ into the output path.
The 1⁄4" 3-pole ‘A’ gauge jacks are bypassed except when a
plug is inserted.
3. RETURN LEVEL
The level of the signal at the RETURN input (1, above) is set
by a rotary control. A panel marking indicates the nominal
unity gain position.
4. PAN
The Group PAN control determines the position of the signal
within the stereo image which is routed to the mix L/ R busses
when L-R is pressed. Rotation fully anticlockwise feeds the
signal solely to the Left mix buss, while rotation clockwise
sweeps the image to the right.
5. PFL
When the PFL switch is pressed, the pre-fade Group signal is
fed to the headphones and RIGHT/PFL METER where it
replaces the mix signal. The AFL/PFL LED on the master
section illuminates to warn that the headphones and meter
are now responding to the AFL/ PFL selection and the PFL
LED on the Group lights to identify the active Group.
6. GROUP FADER
Long throw faders are provided for each Group with unity
gain at the top of their travel.
GROUP
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7. GROUPOUTPUT
The Group outputs are driven by ground compensated
amplifiers to a standard 1⁄4" 3 pole ‘A’ gauge jack socket.
M ASTER SEC TIO N
8. D.C. POWERSOCKET
The cable from the power supply connects to the console via
this 5-pin socket.
Ensure that you always use the correct power supply for your
console. The 12, 16 and 24 channel frame sizes require the
DCP100 power supply and the 32 channel frame uses the
CPS150power supply.
9. MONO OUTPUT
The ground compensated MONO output is a sum of the
postfade Mix Left and Right outputs, providing a separately
controlled feed which may for instance be used to drive a
centre loudspeaker cluster via a suitable power amplifier.
10. MIX L & R OUTPUTS
The MIX L & R outputs are standard male XLR-3 connectors,
driven by ground compensated amplifiers.
11. INSERTS
These are similar to the Input Channel Inserts and allow
external processing equipment to be ‘inserted’ into the output
signal path. The 1⁄4" 3 pole ‘A’ gauge jack sockets are
by-passed except when a plug is inserted.
12. BARG RAPH M ETERS
Six 12-segment, three colour bargraph meters provide visual
monitoring of the levels of the Mix Left and Right, and Group
outputs. All the meters are peak reading.
Normally the Left and Right meters show the level of the Mix
Left and Right outputs. If any PFL or AFL switch is activated
the left meter is turned off and the right meter displays the
level of the selected PFL or AFL signal.
The bargraphs may be calibrated by trimmers accessed via
holes in the panel below each meter. Adjustments may be
made using a small screwdriver, taking care not to damage
the trimmers.
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