Soundcraft SM24 USER GUIDE

SOUNDCRAFT

USER GUIDE

 Soundcraft Electronics Ltd. 1994

All rights reserved

Parts of the design of this product may be protected by worldwide patents.
Part No. ZM0057/02

Issue 2

Information in this manual is subject to change without notice and does not
represent a commitment on the part of the vendor. Soundcraft Electronics Ltd.
shall not be liable for any loss or damage whatsoever arisin g 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 rec ording, for any purp ose
without the express written permission of Soundcraft Electronics Ltd.

It is recommended that all maintenance and service on the product should be
carried out by Soundcraft Electronics Ltd. or its authorised agents. Soundcraft
Electronics Ltd. cannot accept any liability whatsoever for any loss or damage
caused by service, maintenance or repair by unauthorised personnel.

Soundcraft Electronics Ltd.
Cranborne House
Cranborne Industrial Estate
Cranborne Road
Potters Bar
Herts.
EN6 3JN
England

Tel: [phone]
Fax: [phone]

Contents

Introduction 1

Introduction 2
Precautions and Safety Instructions 3

Installation 5

Wiring Considerations 6
Power Supply (CPS950) 6
Connections 7

Module Block Diagrams 9

Input Module 10
Group Output Module 11
Master Module 12

Input Module 13

Module Description & Operation 14

Output Module 21

Module Description and Operation 22

Master Module 29

Module Description & Operation 30

VCA Master Module 37

Module Description & Operation 38

Console Linking 39

Appendices 41

Specifications 42
Dimensions & Configurations 44
Warranty 45
Glossary 46

Introduction

Introduction 1

Intro du c tion

The SM24 has been designed in consultation with top engineers to provide the
ultimate tool for onstage monitor mixing.

The key features of the SM24 are:

• A total of 26 busses reconfigure to provide almost any combination of mono

and stereo mixes

• Dedicated stereo send, for sidefills or main mix output in FOH applica tions

• 4 band parametric EQ plus variable High-Pass filter on all input channels

• Logic controlled solo system with autocancel, input priority and solo clear

functions

• Full audio and logic console linking

• VCA and Mute Masters offer a total of 16 mute groups

• All inputs and outputs fully balanced

• Channel Inserts and Direct Outputs are Ground Compensated as standard

Frame Sizes

Power Supplies

Lamps

The SM24 is available in 3 compact frame sizes:

• 32 channel

• 40 channel

• 48 channel

All frame sizes use the CPS1000 PSU. Connection to the console is via an 8-way
and a 16-way SRC connector. The SRC panel also carries a ground binding post.

Three BNC connectors for lamps are fitted to all frame sizes - one on the master
module, and one at either end of the console on the infill panels. The are suitable
for Littlite or similar 12V lamps taking up to 330mA each. The voltage supply to
the lamps can be varied between 1.5V (dim) and 12V (bright) by the dimmer control.

The console features rear COMM S LI NK conn ectors to allow a Clearcom sy stem
to be looped through. When a ’call’ button is pressed on the Clearcom unit, the
lamps are flashed to signal the engineer.

2 Introduction

Precautions and Safety Instructions

General Precautions

Caution!

Handling and Transport

Power Supplies & cables

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 c ause
damage to paint or plastic parts.

Avoid using the console close to strong sources of electromagnetic radiation (e.g.
video monitors, highpower 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.

In all cases, refer servicing to qualified personnel.

The console is supplied in a wooden crate. 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 regula rly moved we
recommend that it is installed in a foamlined flightcase. At all times avoid applying
excessive force to any knobs, switches or connectors.

Always make sure that the power supply unit (PSU) has been set to the same voltage
as the mains supply

Warning!

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.

Always switch the power supply off before connecting or
disconnecting the mixer power cable, removing of 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.

Always ensure that you use the correct PSU for your mixer. The SM24 uses a
CPS1000 power supply.

Introduction 3

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 reduc e the
available signal range on the inputs. Note that 0dBu = 0.775V RMS.

The microphone inputs are designed for use with balanced low impedance (150 or
200 ohms) microphones.

Caution!

DO NOT use unbalanced microphones or battery powered
condenser microphones without isolating the +48V phantom power:
degraded performance or damage to the microphone may result.

The sensitivity of the XLR inputs is variable from -2dBu to -70dBu and +10dBu to

-20dBu in two ranges (for +4dBu at the Mix outputs). The maximum input level is
+18dBu for the first range, and +30dBu for the second range.

The Hi-Z inputs have a sensitivity variable between +10dBu and -20dBu. The
maximum input level is +30dBu.

The main outputs of the console (stereo mix, groups, wedge and mix and group
insert sends) are balanced at a nominal level of +4dBu, with a maximum output
level of +26dBu.

The input insert sends and direct outputs are ground co mpensated at a nominal level
of -2dBu, with a maximum output level of +20dBu.

All external inputs and mix and group insert returns have a nominal level of + 4dBu,
and a maximum input level of +26dBu.

Input insert returns have a nominal level of -2dBu, and a maximum input level of
+20dBu.

4 Introduction

Installation

Installation 5

Ins tallation

The SM24 is designed for reliability and high performanc e, and is built to the highest
standards. Whilst great care has been taken to ensure that installations are made as
troublefree as possible, care taken at this stage, followed by correct setting up will
be rewarded by a long life and reliable operation.

Wiring Considerations

Power Supply (CPS1000)

Warning!

A For optimum performance it is essential for the earthing system to be clean and
noisefree, as all signals are referenced to this earth. A central point should be
decided on for the main earth point, and all earths should be ’star-fed’ from this
point. It is recommended that an individual earth wire be run from each electrical
outlet, back to the system star point to provide a safety earth re ference for each piece
of equipment.

B Install separate mains outlets for the audio equipment, and feed these
independently from any other equipment.

C Avoid locating mains distribution boxes near audio equipment, espec ially ta pe
recorders, which are very sensitive to electroma gn etic field s.

D Where possible ensure that all audio cable screens and signal earths are
connected to ground only at their source.

Always ensure that you use the correct PSU for your mixer. The SM24 uses a
CPS1000 power supply.

Before switching on your SM24 console, check that the mains
voltage selectors on the power supply unit is set to the correct
mains voltage for your area, and that the fuse is of the correct rating
and type. This is clearly marked on the case of the power supply.
Do not replace the fuse with any other type, as this could become a
safety hazard and will void the warranty.

6 Installation

C onnections

Wiring conventions

MICROPHONE INPUTS

TALKBACK INPUTS

EXTERNAL RETURNS

The SM24 uses two different types of audio connec tor: 3-pin XL R a nd
jacks. The latter are used in several configurations, as shown below.

MIX L, R & WEDGE OUTPUTS

GROUP & TB OUTPUTS

1

/4" ‘A’ Gauge Stereo Jack Plug used as balanced input:

Line inputs, insert returns

AFL & PFL OUTPUTS

1

⁄

" 3-pole

4

1

/4" ‘A’ Gauge Stereo Jack Plug used as ground compensated output:

Input insert sends, Input direct outputs

1

/4" ‘A’ Gauge Stereo Jack Plug used as balanced output:

Mix insert sends, Group insert sends

1

/4" ‘A’ Gauge Stereo Jack Plug used as stereo output: Headphones

Installation 7

8 Installation

Module Block Diagrams

Module Block Diagrams 9

+48V

Input Module

INPUT

HI - Z

INPUT

INSERT

SEND

INSERT

RETURN

DIRECT

OUT

MUTE/VCA BUSSES

MUTE

MUTE

VCA

VCA

VCA IS BYPASSED WHEN CHANNEL

NOTE:

IS NOT ASSIGNED TO VCA GROUPS

TX

OPTION

MUTE

LOGIC

VCA

LOGIC

SENS

INSERT

Ø

PREEQPRE

MUTE

TO

METER

MUTE

GRP 1 - 8

PRE-FADE

SOURCE

FILTER

HI-PASS FILTER

SEND

PEAK

VCA

PRE
FADE

1

2

3

4

5

6

RET

FADER

INSERT

PRE EQ

POST
FADE

LO MID

LF

L/R SEND
PRE-FADE
SOURCE

9A

9B

1 A

1 B

11A

11B

HI MID

L/R

GRP 9 - 16
PRE-FADE
SOURCE

STEREO

9

STEREO

1

HF

PAN

PFL BUS

GROUP 1 - 24 BUSSES

R STEREO BUS

L STEREO BUS

INSERT

POST EQ

CLEAR

R
L

13A

13B

14A

STEREO

13

14B

15A

STEREO

14

15B

STEREO

7

8

12A

12B

11

STEREO

12

16A

16B

STEREO

15

STEREO

16

10 Module Block Diagrams

R AFL BUS

L AFL BUS

PFL BUS

GROUP 1 - 8 BUS

GROUP 9 - 16 BUS

R STEREO BUS

L STEREO BUS

Group Output Module

CLEAR

CLEAR

SUMMING

AMP

SUMMING

AMP

FADER

CLEAR

STEREO

FADER

AFL

TRIM

AFL

TRIM

INSERT

INSERT INSERT

INSERT

EBOS

VOL

TB/OSC

METER

EBOS

EBOS

+

-

+

-

CLEAR

EXT

IN

GROUP

OUT

INSERT

SEND

INSERT

RETURN

EXT
VOL

TB/OSC

LEFT HAND

METER

MONO GROUP

STEREO GROUP

+

-

+

-

EBOS

EXT IN

A

EXT IN

B

GROUP

OUTPUT

A

SUMMING

AMP

EBOS

+

-

RETURN B RETURN A

-

SEND B SEND A

EBOS

+

RIGHT HAND

METER

UPPER SECTIONS OF GROUP MODULE

NOTE:

MAY BE CONFIGURED AS TWO MONO OR
ONE STEREO GROUP

GROUP

OUTPUT

B

Module Block Diagrams 11

Master Module

EXT
PFL

EXT

AFL L

EXT

AFL R

AFL R

OUT

AFL L

OUT

PFL

OUT

TB MIC

L AFL BUS

PFL BUS

GROUP BUSSES

R STEREO BUS

PFL

L STEREO BUS

TRIM

INPUT

PRIORITY

MIX

DEFAULT
MONITOR
SOURCE

SOLO

TO METER LEFT
TO METER RIGHT

WEDGE

FADER

DIM

MIX L

POSTFADE

DIM

PHONES

MIX R

POSTFADE

TB TO

PHONES

ENABLE

OSC

EXT

17V

24V

63 -1KHZ

LEVEL

LEVEL

R

L

WEDGE

OUTPUT

LEFT

WEDGE

OUTPUT

RIGHT

PHONES
OUTPUT

OSCILLATOR

OUTPUT

SOLO CLEAR

R AFL BUS

-

+

-

+

-

+

PFL ENABLE

AFL ENABLE

WEDGE DIM

48V

FREQ

AUTO

CANCEL

GAIN

IN

ENABLE
TB TO
PHONES

15V

CARRIER

ENABLE

CLEAR

AUDIO

ENBL

TALKBACK &
OSCILLATOR

TO

OUTPUTS

+

-

15V

CARRIER

DETECT

FOH

TALKBACK

OUT

FOH

TALKBACK

IN

CLEAR

SUMMING

AMP

STEREO

FADER

AFL

TRIM

AFL

INSERT

EBOS

+

EXT
VOL

TB/OSC

-

+

-

EXT

INPUT

LEFT

EXT
INPUT
RIGHT

OUTPUT

LEFT

EBOS

MIX

OUTPUT

RGHT

SUMMING

AMP

RETURN RETURN

SEND SEND

INSERT R INSERT L

12 Module Block Diagrams

MIX

Input Module

Input Module 13

Input Module

1

Input XLR or the HI-Z Input jack.

+

2
4

/

1

3
5

6

8

2

3 of the input XLR. An integral LED glows when the phantom power is on.

3

and +10dBu to -20dBu. When the RNGE switch is released, the input range is -2dBu
to -70dBu, and the input is via the input XLR connector on the rearcon. When the
RNGE switch is depressed, the input range is +10dBu to -20dBu, and the input is
via the HI-Z jack or the input XLR connectors on the rearcon: the XLR is normalled
to the jack.

Note: Phantom power is not applied to the Hi-Z jack.

4

on the XLR or the jack).

SEN

The

The

The

The

sitivity Control adjusts the level of the signal which is present on the

48V

switch, when it is depressed, places 48V phantom power on pins 2 &

RNGE

(Range) switch selects between an input range of -2dBu to -70dBu,

PHASE

switch reverses the phase of the input signal (whether presented

Highpass Filter

7

The

FIL

ter control sets the cutoff (-3dB) frequency of the high-pass filter: it is

5

adjustable between 30Hz and 400Hz. The c ontrol also has a built-in switch to switch
the filter out of circuit.

9

Frequency Response Curves of the Hig h-Pass Fi lter

Insert Point

6

The Insert Point may be switched in circuit by the

integral LED glows when the Insert point is in circuit.

The Insert Point uses a ground compensated send and an electronically balanced
return. It is accessible via the Insert Send a nd the Insert Return jacks on the rearc on.
The Insert Send is normalled to the Insert Return. A balanced output option is
available.

INSERT IN

switch. An

The Insert Point may be set to pre-EQ or post-EQ, via links on the PCB. The default
is pre-EQ.

14 Input Module

EQ

Equalisation is achieved by a 4-band parametric EQ section.

7

The EQ may be switched in or out of circuit by the EQ switch. An integral LED

glows when the EQ is in circuit.

8

Each of the four bands has a switc h an d a dua l-c onc entric pot. In e ac h c a se the
switch selects the Q factor of the band. The cho ice is between a Q of 0.5, 1.2 or 2.5
Each dual-concentric pot controls the cut/boost and the centre freque ncy (for HMF
and LMF) or cut-off frequency (HF and LF). The outer knob is for frequency
control, the inner knob is for cut/boost (+/-15dB)

The Frequency Response Curves of the Equaliser

dB

LF Section

20.0

15.0

10.0

5.0

0.0

-5.0

-10.0

-15.0

-20.0
20 100

LF EQ

dB

LMF Section

20.0

15.0

10.0

5.0

0.0

-5.0

-10.0

-15.0

-20.0
20 100

LMF EQ

Frequency/Hz

Frequency/Hz

1k 10k 20k

1k 10k 20k

dB

HF Section

20.0

15.0

10.0

5.0

0.0

-5.0

-10.0

-15.0

-20.0
20 100

HF EQ

dB

HMF Section

20.0

15.0

10.0

5.0

0.0

-5.0

-10.0

-15.0

-20.0
20 100

HMF EQ

Frequency/Hz

Frequency/Hz

1k 10k 20k

1k 10k 20k

The HF section is a peaking filter, its cut-off frequency is variable between 70 0Hz
and 14kHz.

HMF

The

section is a peaking filter, its peak frequency is variable between 470Hz

and 10kHz.

LMF

The

section is a peaking filter, its peak frequency is variable between 70Hz

and 1.4kHz.

The LF section is a peaking filter, its cut-off frequency is variable between 32Hz
and 660Hz.

Input Module 15

Stereo Group Sends (9-16)

9

Each of these Group sends has two switches and a dual-concentric pot.

9

10

11

Each pair of Group Sends may be Pre or post-fader: this is controlled by the
switch (the Send is pre-fade when the PRE switch is depressed).

Each pair of Group Sends may be switched on and off individua lly: this is done via
the ON switch, the integral LED glows when the Send is On.

The function of the dual-concentric pot depends upon whether the mo dule is being
used in Stereo or Mono mode. The mode is selected by the appropriate output
module.

Stereo Mode

When the module is in Stereo mode, the outer knob is a
knob is a

Mono Mode

When the module is in Mono mode, the outer knob is a
output, and the inner knob is a

Level

control.

Level

control for the A output.

Pan

control, and the inner

Level

control for the B

PRE

Mono Group Sends (1-8)

10

Each of these Group sends has two switches and a

Each Group Send may be Pre or postfader: this is controlled by the
Send is pre-fade when the PRE switch is depressed).

level-control

PRE

pot.

switch (the

16

13

12

14

15

17

Each Group Send may be switched on and off individually: this is done via the
switch, the integral LED glows when the Send is On.

ON

Main Stereo Mix

11

The Send to the Main Mix has two switche s and a

The Send may be Pre or post-fader: this is controlled by the
is pre-fade when the PRE switch is depressed).

The Send may be switched on via the ON switch, the integral LED glows when the
Send is On.

level-control

PRE

switch (the Send

pot.

Level Control

The

CUT

switch mutes the signal at a point post-insert and p ost-EQ. However

12

the pre-fade Send to groups 1-8, 9-16 and to the Main Mix may be set, via links on
the PCB, to one of three options, i.e. pre-insert, pre-mute, post-mute. The CUT
switch will, therefore, only actually Cut those Sends which are switched to
post-fade, or are switched to pre-fade and are set to the post-mute link option.

16 Input Module

13

The level of the post-fade signal is set by a combination of a VCA followed

by the 100mm

14

The VCA may be controlled by any, or all, of the 8 VCA Faders. The VCA
Faders are selected by the VCA
no VCA switches are selected, the VCA is bypassed.

15

The Module may also be muted by any of eight Master Mutes. These are
selected by the Mute

Fader

.

1-8

switches. The selected ones are illuminated. If

1-8

switches. The selected ones are illuminated .

The

Peak

LED illuminates when there is 6dB of headroom left at any of the

16

following 4 points in the module: pre- high-pass filter, post-EQ, post-insert return
and post-fade.

PFL

The

PFL

switch routes the post-insert, post-EQ signal to the PFL bus.

17

Metering

The pre-high-pass filter signal is monitored by a 16-LED Peak Meter in the
Overbridge.

Direct Output

A post-fade signal is available via the
ground compensated output. A balanced output option is available .

DIRECT O/P

jack on the rearcon. It is a

Input Module 17

Input and Output Levels

XLR INPUT

Sensitivity -2dBu to -70dBu, +10dBu to -20dBu
Max. Input Level +18dBu/+24dBu

Input Impedance 2kΩ

HI-Z INPUT

Sensitivity +10dBu to -20dBu
Max. Input Level +30dBu

Input Impedance >10kΩ balanced

INSERT SEND

Sensitivity -2dBu +4dBu
Max. Output Level +20dBu into 2kΩ +26dBu into 1kΩ
Output Impedance <75Ω <75Ω

INSERT RETURN

Sensitivity -2dBu +4dBu
Maximum Input Level +20dBu +26dBu

Input Impedance >10kΩ balanced >10kΩ balanced

(electronically balanced)

(electronically balanced)

(ground compensated)

Balanced Option

(electronically balanced)

Balanced Option

DIRECT OUTPUT

Sensitivity -2dBu +4dBu
Max. Input Level +20dBu into 2kΩ +26dBu into 1kΩ
Output Impedance <75Ω <75Ω

(ground compensated)

Balanced Option

18 Input Module

Rearcon Panel

The connections on the rearcon panel are a s follows:

INPUT XLR

Pin 1 Gnd (Screen)
Pin 2 Hot (In-phase signal)
Pin 3 Cold(Out-of-phase signal)

HI-Z JACK

Tip Hot (In-phase signal)
Ring Cold(Out-of-phase signal)
Sleeve Gnd(Screen)

INSERT SEND

Balanced Option

Tip Signal Hot
Ring Ground Sense Cold
Sleeve Gnd(Screen) Gnd(screen)

INSERT RETURN

Tip Hot (In-phase signal)
Ring Cold(Out-of-phase signal)
Sleeve Gnd(Screen)

DIRECT OUT

Balanced Option

Tip Signal Hot
Ring Ground Sense Cold
Sleeve Gnd(Screen) Gnd(screen)

Input Module 19

20 Input Module

Output Module

Output Module 21

Output Module

Each of the Eight Output Modules has three sections: The top and centre sections
may be used together in stereo mode, or se parately in mono mode. The lower section
is always in mono mode. The top (B) section controls groups 9-16 Right, the c entre
(A) section controls groups 9-16 Left, and the lower section controls groups 1-8

654

3

7

8

2

1

9

0

2

6

10

0

-

+

10

10

7

4

3

13

8
9

10

11

1

Mono Group (1-8)
Ext Input

1

inserted via the XLR, for the Output Module in question, on the lower re arcon panel.

2

switch has a toggle action. An integral LED indicates when the LSTN switch is
active.

3

question, i.e . one of group 1 to 8. An integral LED indicates when the ON switch
is active.

EXT IN

The

The

LSTN

level-control adjusts the level of the external input which is

switch feeds a pre-level-control signal to the PFL bus. The LSTN

The ON switch routes the signal from the level-control to the Group bus in

5

12
14

Output Level Control

The Group’s Output signal is presented on an XLR on the rearcon.

4

The Group Output level is controlled by the 100mmtravel

Fader.

The post-fade signal is then routed to the insert point.

5

The signal level of the Group Output in question is monitored by the

LED meter

which is next to the Fader. Zero on the meter equals +4dBu at the output.

Insert Point

The Insert Point consists of two jack sockets on the rearcon: a Send and a Return.
The Send is an electronically balanced output, and the Return is an electronically
balanced input. The Send is normalled to the Return.

6

The Insert point may be switched out of circuit by the Insert

integral LED indicates when the Insert point is out of circuit.

OUT

switch. An

22 Output Module

Oscillator/Talkback

7

Any signal on the Talkback/Oscillator bus (the signals are controlled from the

Master Module) are added into the Group Output in question when the TB/OSC

ENBL

switch is selected. An integral LED indicates when it is active.

The ENBL switch has a dual-action facility: if you press and hold the switc h down
the switch acts as a press-and-hold switch, i.e. it will be inactive again when you
release it, but if you press and release within 0.3-0.5 seconds (nominally) then the
switch will be latched active; to release the switch again you must pre ss and release
it once more.

Output Switching

8

The L switch feeds the Group’s post-fade, post-insert signa l to the L Stereo bus.
An integral LED indicates when it is selected. This is used in a FOH application,
when using the outputs as mixing subgroups.

9

The R switch feeds the Group’s post-fade, post-insert signal to the R Stereo bus.
An integral LED indicates when it is selected. This is used in a FOH application,
when using the outputs as mixing subgroups.

10

The Phase switch (∅) reverses the phase of the Group’s output signal. An

integral LED indicates when it is selected.

The

CUT

switch will isolate the post-fade, post-insert signa l from the Group’s

11

Output and the Stereo buses. An integral LED indicates when it is selected.

AFL

12

The AFL (After-Fade Listen) may be sourced pre or post the insert point. The
option you require is selected via the Insert
when pre-insert is selected.

13

The level of the AFL signal is controlled by the

14

The AFL signal is switched through to both AFL L and AFL R buses by the

AFL

switch. An integral LED glows when AFL is active on the Group in question.
The AFL may be switched off by pressing the AFL switch again, or by the Solo
Logic system which is controlled from the Master Module.

PRE

switch. An integral LED glows

AFL TRIM

pot.

Output Module 23

Mono/Stereo Group (A)

31

34
35

17
18

21
22

654

3

7

30

8

2

1

9

0

10

32

The A section controls the Groups 9-16 A when in Mono Mode, and 9-16 A & B
when in Stereo Mode

The differences between Group A in Mono Mode and Group A in Stereo Mod e are
summarised as follows:

41

36
37
38

-

-

-

+

33

39
40

42

LSTN Mono Mode - External Input A is routed to the PFL bus.

Stereo Mode - Mono Mix of Ext. Input A & B is fed to the PFL bus.

L Mono Mode - The Group A signal is fed to the L stereo bus.

Stereo Mode - The Group A signal is fed to the L stereo bus.

R Mono Mode - The Group A signal is fed to the R stereo bus.

Stereo Mode - The Group B signal is fed to the R stereo bus.

PHASE Mono Mode - The Group A Output signal is phase-reversed.

Stereo Mode - Both the Group A and Group B signals are

phase-reversed.

AFL Mono Mode - The Group A AFL signal is fed to both L & R AFL buses.

Stereo Mode - The Group A and Group B AFL signals are fed to the

L & R AFL buses respectively.

15

654

7

3

2

1

0

10

16

8

9

19
28

Mode

15

The Mode
Output Module in question to be used as a stereo pair. When the switch is a ctive all
of the B controls are inactive: both Groups are controlled by A’s controls and the
LEDs in the B section are turned off. An integral LED shows when Stereo Mode
is active. This LED is repeated alongside the fader for convenience .

STE

reo switch, when active, allows the A and B Groups on the

23
24

The STEreo switch also switches the appropriate send on the Input Modules from
Mono to Stereo. Note: It is not intended that this switch is used in a live situation.

25
26

Ext Input

The external input is intended for receiving the outputs of a slave console, when

20

console linking is required.

The

EXT IN

level-control adjusts the level of the external input which is

16

inserted via the XLR, for the Output Module in question, on the lower re arcon panel.

The

MONO

switch, when depressed, feeds a summed signal from External

17

Inputs A and B to both sides of the stereo pair. This only sums the External Inputs,
it does not sum the A and B Groups. This switch only operates when the Output
Module is in Stereo Mode.

27
29

switch has a toggle action. An integral LED indicates when the LSTN switch is
active. In Mono Mode, the A External Input signal is fed to the PFL bus, whilst in
Stereo Mode a mono sum of the A & B inputs is fed to the PFL bus.

19

18

question, i.e . one of group 9 to 16 Left. An integral LED indicates when the ON
switch is active.

24 Output Module

LSTN

The

switch feeds a pre-level-control signal to the PFL bus. The LSTN

The ON switch routes the signal from the level-control to the Group bus in

Output Level Control

The Group’s Output signal is presented on an XLR on the rearcon.

20

The Group Output level is controlled by the 100mm-travel

The post-fade signal is then routed to the insert point.

The signal level of the Group Output in question is monitored by the Group’s LED
meter which is located in the overbridge. Zero on the meter equals +4dBu at the
output.

Fader

.

Insert Point

The Insert Point consists of two jack sockets on the rearcon: a Send and a Return.
The Send is an electronically balanced output, and the Return is an electronically
balanced input. The Send is normalled to the Return.

21

The Insert point may be switched out of circuit by the Insert
integral LED indicates when the Insert point is out of circuit.

OUT

switch. An

Oscillator/Talkback

22

Any signals on the Talkback/Oscillator bus (the signals are controlled from
the Master Module) are added into the Group Output in question, and the Group
Output is dimmed by 6dB, when the TB/OSC
LED indicates when it is selected.

ENBL

switch is selected. An integral

The ENBL switch may be ’armed’ in advance of the Oscillator or Talkback being
selected on the Master Module.

The ENBL switch has a dual-action facility: if you press and hold the switc h down
the switch acts as a press-and-hold switch, i.e. it will be inactive again when you
release it, but if you press and release within 0.3-0.5 seconds (nominally) then the
switch will be latched active; to release the switch again you must pre ss and release
it once more.

Output Switching

23

The L switch feeds the Group’s post-fade, post-insert signal to the L Stereo
bus. An integral LED indicates when it is selected. This is used in a FOH
application, when using the outputs as mixing subgroups.

24

In Mono Mode the
to the R Stereo bus. In Stereo Mode the B signal is sent to the R stereo bus. An
integral LED indicates when it is selected. This is used in a FOH application, when
using the outputs as mixing subgroups.

25

In Mono Mode the Phase switch (∅) reverses the phase of the Group’s output

signal. In Stereo Mode the phase of both A & B signals is reversed. An integral
LED indicates when it is selected.

R

switch feeds the Group’s post-fade, post-insert signal

The

CUT

switch will isolate the postfade, postinsert signal from the Group’s

26

Output and the Stereo buses. An integral LED indicates when it is selected.

Output Module 25

31

AFL

27

654

3

7

30

8

2

1

9

0

10

32

The AFL (After-Fade Listen) may be sourced pre or post the insert point. The

option you require is selected via the Insert

PRE

switch. An integral LED glows

when pre-insert is selected.

34
35

17
18

21
22

28

The level of the AFL signal is controlled by the

AFL TRIM

pot.

41

29

36
37
38

-

-

-

+

33

39
40

In Mono Mode the AFL signal is switched through to both AFL L and AFL

R buses by the

AFL

switch. In Stereo Mode the A & B signals are routed to the L
AFL bus and R AFL bus respectively. An integral LED glows when AFL is active
on the Group in question. The AFL may be switched off by pressing the AFL switch
again, or by the Solo Logic System which is controlled from the Master Module.

Mono Group (B)

The B controls are only active when A & B are in Mono Mode.

42

Ext Input

15

654

7

3

2

1

0

10

16

8

9

19
28

23
24
25

The ext input is intended for receiving the outputs of a sla ve console, when console
linking is required.

The

EXT IN

level-control adjusts the level of the external input which is

30

inserted via the XLR, for the Output Module in question, on the lower re arcon panel.

The

LSTN

switch feeds a pre-level-control signal to the PFL bus. The LSTN

31

switch has a toggle action. An integral LED indicates when the LSTN switch is
active.

32

The ON switch routes the signal from the level-control to the Group bus in
question, i.e . one of group 9 to 16 B. An integral LED indicates when the ON switch
is active.

26

Output Level Control

20

The Group’s Output signal is presented on an XLR on the rearcon.

33

The Group Output level is controlled by the

LEVEL

pot. The post-pot signal

is then routed to the insert point.

The signal level of the Group Output in question is monitored by the Group’s LED
meter which is located in the overbridge. Zero on the meter equals +4dBu at the
output.

27
29

26 Output Module

Insert Point

The Insert Point consists of two jack sockets on the rearcon: a Send and a Return.
The Send is an electronically balanced output, and the Return is an electronically
balanced input. The Send is normalled to the Return.

34

The Insert point may be switched out of circuit by the Insert

integral LED indicates when the Insert point is out of circuit.

OUT

switch. An

Oscillator/Talkback

35

Any signal on the Talkback/Oscillator bus (the signals are controlled from the
Master Module) are added into the Group Output in question, and the Group Output
is dimmed by 6dB, when the TB/OSC
indicates when it is selected.

The ENBL switch may be ’ARMED’ in advance of the Oscillator or Talkback being
selected on the Master Module.

The ENBL switch has a dual-action facility: if you press and hold the switch down
the switch acts as a press-and-hold switch, i.e. it will be inactive again when you
release it, but if you press and release within 0.3-0.5 seconds (nominally) then the
switch will be latched active; to release the switch aga in you must press a nd release
it once more.

ENBL

switch is selected. An integral LED

Output Switching

36

The L switch feeds the Group’s post-fade, post-insert signal to the L Stereo
bus. An integral LED indicates when it is selected.

37

The R switch feeds the Group’s post-fade, post-insert signal to the R Stereo
bus. An integral LED indicates when it is selected.

38

The Phase switch (∅) reverses the phase of the Group’s output signal. An
integral LED indicates when it is selected.

The

CUT

switch will isolate the post-fade, post-insert signal from the Group’s

39

Output and the Stereo buses. An integral LED indicates when it is selected.

AFL

40

The AFL (AfterFade Listen) may be sourced pre or post the insert point. The
option you require is selected via the Insert
when pre-insert is selected.

41

The level of the AFL signal is controlled by the

42

The AFL signal is switched through to both AFL L and AFL R buses by the

AFL

switch. An integral LED glows when AFL is active on the Group in question.
The AFL may be switched off by pressing the AFL switch again, or by the Solo Logic
system which is controlled from the Master Module.

PRE

switch. An integral LED glows

AFL TRIM

pot.

Output Module 27

Input and Output Levels

Rear Connectors

Insert Sends, Group Outputs

Nominal level +4dBu
Maximum output level +26dBu into 1kΩ
Output impedance <75Ω

Insert Returns, External Inputs

Sensitivity +4dBu
Maximum i/p level +26dBu

Input impedance >10KΩ balanced

Group Outputs,

Pin 1 Ground
Pin 2 Signal (Hot)
Pin 3 Signal (Cold)

Insert Return

(3 pin male XLR)

(1/4" 3-pole Jack)

(electronically balanced)

(electronically balanced)

PUSH

PUSH

Tip Signal (Hot)
Ring Signal (Cold)
Sleeve Ground

Insert Send,

Tip Signal (Hot)
Ring Signal (Cold)
Sleeve Ground

External Inputs

Pin 1 Ground
Pin 2 Signal (Hot)
Pin 3 Signal (Cold)

(1/4" 3-pole Jack)

(3-pin female XLR)

28 Output Module

Master Module

Master Module 29

Mas ter Module

Oscillator

1

1

654

3

7

8

2

1

9

0

10

2

3

5

654

3

7

8

2

1

9

10

0

4

6

When the OSCILLATOR ON switch is active (an integral LED indica tes this),
the output from the oscillator is put on the Talkback/Oscillator bus; it is also
switched to the Oscillator Output XLR on the rearcon.

2
3

LEVEL

The

control adjusts the level of the Oscillator signal.

The frequency of the oscillator may be varied. There are two ranges: 63Hz to
1kHz, and 630Hz to 10kHz. The frequency that you want is set by using the ro tary

FREQ

control and the

4

The output of the oscillator may be switched between a sinusoidal output or
pink noise. This is done via the

X10

switch.

TONE

switch: the integral LED indicates when the
sinusoidal output is selected. Note that when the pink noise output is selected, the
frequency controls have no effect.

7

10
13

15
19

14

8

Power-Supply Monitor

9

5

Three LEDs provide a quick confidence check that all is OK with the power

supply.

654

3

7

2

1

9

0

10

11

8

12

Talkback

The Talkback System has two inputs available: one is the TB MIC IN XLR o n the

18

rearcon panel, the other is the FOH TALKBACK IN XLR, also on the rearcon pane l.

The FOH TALKBACK IN has a signal detect feature, this allows the
Front-Of-House console to page the SM24, i.e. if a 15V(nominal) DC signal is

20
21

placed on the audio input pins (in addition to any audio signal), the SM24 will route
the FOH input to the phones, and the Wedge Output will be dimmed.

6

The rotary control sets the gain of the TB MIC preamplifier.

The

EXT

switch routes the FOH Input signal to those groups which have been

7

armed by their OSC/TB ENBL switches or when their OSC/TB ENBL switch is
pressed, and to the Stereo Output if the appropriate OSC/TB ENBL has been armed
or is pressed.

The

INT

switch routes the TB MIC Input signal to those groups which have

8

been armed by their OSC/TB ENBL switches or when their OSC/TB ENBL switch
is pressed, and to the Stereo Output if the appropriate OSC/TB ENBL has been
armed or is pressed.

9

The momentary FOH switch routes the TB MIC signal to the FOH Output. This

16
17

allows the Stage Engineer to talk to the FOH engineer. The FOH output has 15V
DC(nominal) superimposed on it to page the FOH console (this may be disabled
by an on-board link).

30 Master Module

Stereo Output

This is intended for sidefills or as the main mix in FOH applications. There is a
stereo input which directly feeds the main mix buses. This input is via two XLRs
on the rearcon panel.

10

to the main mix buses.

11

mix buses. This is intended for receiving the outputs of a slave console, when
console linking is required.

12

when it is on.

13

’phones or wedge output. LISTEN is affected by the AUTOCANCEL or SOLO
CLEAR functions, and overrides any output AFLs if INPUT PRIORITY is a ctive.

MONO

The

EXT IN

The

The ON switch activates the External inputs. An integral gre en LED indicates

The LSTN (listen) switch provides a mono pre-fade, pre-ON solo to the

switch, when depressed sends a mono sum of both external inputs

pot adjusts the level at which the external input is fed to the main

Level Control

The Stereo Output L & R signals are presented on two XLRs on the rearcon.

14

The Output Level is controlled by the 100mm travel

signal is then routed to the Stereo Output insert points.

Fader

. The post-fade

Insert Points

Each of the two insert points consists of two jack sockets on the rearcon: A Send
and a Return. The Send is an electronically balanced output, and the Return is an
electronically balanced input. The Send is normalle d to the Re turn.

15

The Insert point may be switched out of circuit by the Insert

integral LED indicates when the Insert point is out of circuit.

16

The PRE INSERT switch moves the AFL signal before the insert point.

17

The electronically latching AFL switch feeds the stereo post-fade, post-insert

signal to the engineer’s wedge speakers and phones outp ut.

The

AFL TRIM

pot gives +/-10dB of level adjustment.

18

OUT

switch. An

Oscillator/Talkback

19

Any signal on the Talkback/Oscillator bus (the signals are controlled from the
Master Module) are added into the Stereo Output when the TB/OSC
is selected. The Stereo Output is also dimmed by 6dB. An integral LED indicates
when it is active.

ENBL

switch

Master Module 31

The ENBL switch may be ‘armed’ in advance of the Oscillator or Talkback being
selected.

The ENBL switch has a dual-action facility: if you press and hold the switc h down
the switch acts as a press-and-hold switch, i.e. it will be inactive again when you
release it, but if you press and release within 0.3-0.5 seconds (nominally) then the
switch will be latched active; to release the switch again you must pre ss and release

1

it once more.

654

3

7

8

2

1

9

0

10

2

Output Switching

3

20

The Phase switch (∅) reverses the phase of the stereo output’s signal. An
integral LED indicates when it is selected.

5

654

3

7

8

2

1

9

10

0

7

4

The

CUT

switch will isolate the post-fade, post-insert signal from the Stereo

21

Output. An integral LED indicates when it is selected.

6

The Solo System

8

Logic

9

The Logic control has 4 different modes.

10
13

15
19

14

654

3

7

2

1

9

0

10

11

8

12
18

20
21

Mode

‘Normal’

‘Autocancel’

‘Input priority’

‘Input/output
Autocancel
with I/P priority’

Autocancel
button

0 (=off)

X (=on)

0

X

Input priority
button

0

0

X

X

Description

All output and input solos are
additive

All solos Autocancel, no distinction
between output and input

If an output is left on solo, soloing an
input will temporarily override the
output but will return to it when the
input is unsoloed

Combination of the last two

- as input priority, but also with
Autocancelling between groups of
outputs and groups of inputs

In addition to the above features, there is a ‘Solo Clear’ button which illuminates as
soon as any solo is active and can be pressed to cancel all solos instantly.

Audio

The actual monitoring point for the solo system is the ‘engineers listening wedge’
output, which is a fader controlled stereo output. Normally, with no solos active,
this output is quiet (although it can be internally jumpered to monitor stereo sidefill
output in the absence of a solo). Although the output is stereo, there are buttons to

16

enable the left, right or both signals to be sent to both wedges, for checking or for
use when only one wedge is connected.

17

Inputs when soloed give a mono PFL signal onto the Stereo engineers’ listening
wedge output (The phones output is driven from the same feed but with its own leve l
control). An overall ‘PFL trim’ control on the Master gives +/-10dB adjustment of
PFL level.

32 Master Module

23

If the output section is configured as separate mono sends, then any output soloed
will give a mono AFL signal to the engineer’s wedge. This can be adjusted +/-10dB
by the ‘AFL trim’ control on each output.

If however any output pair is switched to Stereo Mode (this can be done globally
on each of the outputs 9A/B to 16A/B), then the AFL will aslo appear a utomatically
in stereo, as it does permanently with the stereo sidefill output on the Master module.

25

27

3

2

1

456

0

22

22

When

INPUT PRIORITY

is selected by the

integral red LED, an active PFL or LISTEN will replace any AFL signals, which

ENBL

switch, which has an

will be audible only when all the PFL/LISTENs are released.

24

23

7

26

8

9

10

28

24

Pressing it will clear a PFL, AFL, and a LISTEN.

25

integral red LED, any AFL, PFL or LSTN will cancel any currently active solo, so
only one AFL, PFL or LSTN can be active at once.

External Solo Signals

The PFL, AFL Left and AFL Right external inputs, from XLRs on rearcon, allow
signals from another console to be added to the PFL and AFL buses.

The external PFL level is trimmed by the PFL TRIM pot. When no solos are active
on the console, both PFL and AFL left and right external signals are monitored by
the ’phones and wedge. When INPUT PRIORITY is not a ctive, the externa l signals
are mixed with any current internal PFL, AFL or LISTEN signals; if INPUT
PRIORITY is enabled and a PFL/LISTEN is active then the external AFL input is
cut.

PFL TRIM

The

SOLO CLEAR

The

When

control gives +/-10dB of level trim for PFL/LISTEN signals.

button lights when any AFL, PFL or LISTEN is active.

AUTO CANCEL

is activated by the

ENBL

button, which has an

Internal jumpers allow the signal fed to the ’phones/wedge when no solos are active
to be changed from the external PFL/AFL signals (as described above) to the stereo
mix postfade signal. This will be replaced by any active solo signal. To monitor the
external PFL/AFL inputs in this case, a solo on the console must be presse d.

PFL and AFL Outputs

The PFL, AFL left and AFL right output signals are available on XLRs on the rear
connector panel, ground compensated at +4dBu. The se are for use when linking the
console (as a slave), or for additional monitoring.

Metering

The current solo signal is metered by two LED meters in the overbridge; the AFL
signal from the stereo mix is displayed in ster eo while mono AFLs (from the groups)
and PFL/LISTEN signals (taken after the PFL trim pot) are fed to both left and right
meters.

Master Module 33

23

Wedge and Headphones Outputs

The wedge (operator’s speaker) and headphones outputs share a common signal
source: when no PFL, AFL or LISTENs are active, then the source is either the
external PFL and AFL inputs, or the stereo mix signal, according to internal jumper
settings. The wedge output is dimmed by 20dB and the headphones output by 15dB
during talkback.

25

27

2

3

1

456

0

22

When a solo is active the signal is the console AFL or PFL signal, summed with the
external PFL and AFL signals as described in the previous section.

24

26

The headphones output level is adjusted by the

is available on a 1/4" 3-pole jack on the VCA Master Module, duplic ated on the rea r

7

26

8

9

10

28

panel.

27

The stereo wedge output level is controlled by the 100mm wedge

is balanced at +4dBu on XLRs.

28

When the L switch is depressed, the Left signal is fed to both Left & Right
Wedge outputs. Similarly, when the R switch is depressed, the Right signal is fed
to both Wedge outputs. When the L and R buttons are both depressed, a
mix of the Left and Right signals is fed to both Wedge outputs. The L & R buttons
also operate on the headphone output.

Comms Link

The comms link is designed to pick up the call signal from a Clear-com intercom
and use this to flash the console’s Littlites, in order to draw the engineer’s a ttention.
There is no connection to the Clear-com audio in any way.

Notes:

PHONES

control ; the output

Fader

and

MONO

1 The Comms Link is designed to operate with the Clear-com Series 500

intercom system using 3-pin XLR connectors.
2 The Comms Link connections are optically isolated from the console.
3 The Comms Link will only operate if both the +30Vdc and the DC Call

Signal (+4Vdc to +11Vdc) are present.
4 The Comms Link will also operate with the ‘TW’ option on the

Clear-com system where an additional audio channel is superimpose d on

the +30Vdc.
5 The lamps flash between dim and a preset brightness which is independent

of the dimmer control.

WARNING!

The Clear-com system cables include +30Vdc and must not be connected to
any other input or output of the console.

34 Master Module

Input and Output Levels

INSERT SENDS, MIX, WEDGE AND FOH TALKBACK OUTPUTS
(Electronically Balanced)

nominal level +4dBu
maximum output level +26dBu into 1kΩ
output impedance <75Ω

OSCILLATOR OUTPUT (Electronically Balanced)

nominal level +4dBu
maximum output level +14dBu into 600Ω
output impedance <75Ω

PFL, AFL LEFT AND RIGHT OUTPUTS (Ground Compensated)

nominal level +4dBu
maximum output level +20dBu into 2kΩ
output impedance <75Ω

INSERT RETURNS, EXTERNAL AND FOH TALKBACK INPUTS
(Electronically Balanced)

sensitivity +4dBu
maximum i/p level +26dBu

input impedance >10KΩ balanced

TALKBACK MICROPHONE INPUT (Electronically Balanced)

sensitivity -20dBu to -50dBu
maximum i/p level 0dBu

input impedance 2kΩ

PHONES OUTPUT (Unbalanced)

nominal level +4dBu
maximum output level +20dBu into 600Ω
0dBu into 8Ω
output impedance 50Ω

Rear Connectors

External Inputs, External Talkback In, Talkback Mic In

(3-pin female XLR)

Pin 1 Ground
Pin 2 Signal Hot
Pin 3 Signal Cold

Insert Returns

Tip Signal Hot
Ring Signal Cold
Sleeve Ground

Insert Sends

Tip Signal Hot
Ring Signal Cold
Sleeve Ground

(1/4" 3-pole Jack)

(1/4" 3-pole Jack)

Master Module 35

PFL, AFL Left and Right Outputs

Pin 1 Ground
Pin 2 Signal
Pin 3 Ground Sense

(3 pin male XLR)

Oscillator, Mix, Wedge and Talkback Outputs

(3-pin male XLR)

Pin 1 Ground
Pin 2 Signal Hot
Pin 3 Signal Cold

Rear Connector Panels

Phones Output

Tip Left Signal
Ring Right Signal
Sleeve Ground

(Note: the headphones socket is duplicated on the VCA Master Module. )

(1/4" 3-pole Jack)

Comms Link

‘IN’ (3-pin female XLR) & ‘OUT’ (3-pin male XLR)

Pin 1 Common (DC ground & Intercom Low)
Pin 2 +30Vdc from Intercom System
Pin 3 Intercom Line (Audio & DC Call Signal)

(Note: Group Output Connectors have been removed from the diagra m fo r c la r ity).

PUSHPUSH PUSH

36 Master Module

VCA Master Module

VCA Master Module 37

9&$0DVWHU0RGXOH

5

3

This module controls the eight VCA groups (each provided with a MUTE switch)
and the eight additional Mute Groups.

VCA Masters

1

Each
channel assigned to the group by selecting the corresponding input channel VCA
switches.

Pressing the
that group. In this case the CUT switch on the VCA master lights along with the
CUT switches on the muted channels.

Each channel may be assigned to any combination of VCA Groups.

1

VCA MASTER FADER

CUT

switch on the VCA Master will mute all channels assigned to

controls the level of the pre-fade signals in any

Mute Masters

2

selecting the corresponding input channel mute switches.

Inputs may be assigned to any combination of the eight master mute busses. When
an input channel is assigned to a mute bus, it is muted when the corresponding
MUTE MASTER is pressed. The MUTE MASTER switch lights steadily and the
input channel CUT switch also illuminates to indicate that a non-local mute is in
operation. The input channel may be removed from from the bus system by
de-selecting the appropriate bus switch.

MUTE MASTERS

The

will mute any channel assigned to the group by

3
4
5

the Alternate Wedge option is fitted.

2

4

LAMP DIMMER

The

HEADPHONE

ALTERNATE WEDGE OUTPUT

control.

socket.

switch. This switch is functional only if

38 VCA Master Module

Console Linking

Console Linking 39

Console Linking

The SM24 features a Console Linking system which allows a master SM24 to
control a slave SM24 in order to increase the number of inputs.

To implement this, connect the 24 Group outputs, the Stereo outputs and the AFL
& PFL outputs from the Slave to the corresponding external inputs on the Master
console. Using the special 38-way EDAC cable, connect the ‘Logic Link Out’
connector on the Master to the ‘Logic Link In’ connector on the Slave. To avoid
malfunctions, use only one EDAC cable.

To avoid overriding the Master console settings, the controls on the Slave console
must be set as follows:

• All 8 Master Mutes OFF

• All 8 VCA Mutes OFF

• Set all VCA Faders to 0dB

• Set all 24 Group output faders and the Stereo output fader to 0dB

• Deselect all latching switches on the Output and Master modules.

• Set the STE switches on the Output modules to be consistent with those on the

Master console.

• Set Input Priority switches to be consistent on both consoles.

The input modules in the Slave console will function as a n extension of the Master
console. The controls on the Output and Master modules in the Slave should b e left
alone (advanced users may disagree!).

To minimise shifts in ground potentials, the power supplies for the two consoles
should be plugged into adjacent mains outlets.

This logic linking system is not directly compatible with Vienna or Europa consoles
and must not be used with other manufacturers consoles. It is not designed for
linking more than two SM24 consoles.

The audio linking is of course compatible with any other console, simply plug the
slave console’s audio outputs into the SM24’s external inputs.

40 Console Linking

Appendices

Appendices 41

6SHFLILFDWLRQV

Frequency Response

Any input to any output +0/-1.0dB, 20Hz to 20kHz

Total Harmonic Distortion

(All measurements at 20dBu, VCAs bypassed)

Line In to Group or Mix out < 0.007% @ 1kHz

< 0.025% @ 10kHz

Noise

(22Hz - 22kHz bandwidth, unweighted)

Mic Input Equivalent Input Noise < -127.5dBu (200Ω source)
Group Output Noise < -79dBu (40 channels routed)
Mix Output Noise < -79dBu (40 channels routed)

Crosstalk

(All measurements at 1kHz)

Input Channel Muting > 90dB
Input Channel Send Pot isolation >90dB
Input Channel Send ON isolation >90dB
Group Fader isolation >90dB
Group CUT isolation >100dB
Group to Group crosstalk < -80dB
Group to Mix crosstalk < -90dB
Mix to Group crosstalk < -90dB

Input and Output Impedances

Mic Input 2kΩ balanced
Hi-Z and Line Input >10kΩ balanced
Input Insert Send 75Ω gnd. comp.
Input Insert Return >10kΩ balanced
Output Insert Send < 75Ω balanced
Output Insert Return > 10kΩ balanced
Outputs < 75Ω balanced

Input/Output Capability

Mic Maximum Input Level +18dBu
Line Maximum Input Level +30dBu

Input Insert Sends +20dBu into 2kΩ
Input Insert Returns +20dBu

Output Insert Sends +26dBu into 1kΩ
Output Insert Returns +26dBu

All Balanced Outputs +26dBu into 1kΩ
Headphone Output +20dBu into 1kΩ

150mW into 8Ω

42 Appendices

Input and Output Levels

Mic Input Sensitivity (XLR) -2dBu to -70dBu, +10dBu to -20dBu
Line Input Sensitivity (0.25" jack) +10dBu to -20dBu
Input Insert Send/Return -2dBu nominal
Output Insert Send/Return +4dBu nominal
Outputs +4dBu for 0VU

Weights

48 Channel console 170Kg
40 Channel console 140Kg
32 Channel console 110Kg

Specification Notes and Conditions

A The Console has a nominal output level of +4dBu: all input sensitivities are
relative to this, i.e., with line input gain set to ’0’, an input of 0dBu will give an
output of +4dBu at any group or mix output, and a sensitivity of +4dBu gives unity
gain from input to output.

B Noise measurements are taken with 22Hz-22kHz bandwidth, rms-reading
response.

C Distortion measurements are made with a an input of +20dBu (line inputs at
unity gain) giving an output of +20dBu. The analyser reads THD+N with an a verage
response over a 10Hz-80kHz bandwidth.

D Frequency response and EQ measurements are made with an input of 0dBu to
line inputs at unity gain: outputs are quoted relative to 0dBu.

E Crosstalk and rejection measurements are made with an input level of +2 0dBu
(line inputs at unity gain) giving an output of +20dBu on the active signal path. The
ratio quoted is relative to +20dBu output.

F Gain tolerance is +/- 1.5dB or 10% of the indicated value, whichever is the
greater.

G Group Noise: noise measured at the group output with faders at unity, and
channel send pots down.

H Mix Noise: noise measured at the stereo mix output with faders at unity, and
channel sends off.

Appendices 43

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Dimensions - end view

366.5

(14.43")

48 Channel Console

120.6

(4.75")

101.5 (4.00")

892.4

(35.13")

Width :

48 channel - 2213.10mm
40 channel - 1929.90mm
32 channel - 1646.70mm

(87.13")
(75.98")
(64.83")

140.25
(5.52")

40 Channel Console

32 Channel Console

INPUT OUTPUT MASTER

VCA/MUTE

MASTER

44 Appendices

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1 Soundcraft means Soundcraft Electronics 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 ma nua l.

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 compone nt should be re tu rn ed
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.

Appendices 45

*ORVVDU\

Auxiliary Send an output from the console comprising a mix of signals from channels and groups

derived independently of themain stereo group mixes. Typically the feeds to the
mix are implemented on rotary level controls.

Balance the relative levels of the left and right channels of a stereo signal.
Clipping the onset of severe distortion in the signal path, usually caused by the peak signal

voltage being limited by the circuit’s power supply voltage.

CR (Control Room) Monitors loudspeakers used by the operator (engineer) in the control room to listen to the

mix.

dB (decibel) a ratio of two voltages or signal levels, expressed by the equation

dB=20Log10(V1/V2).
Adding the suffix ’u’ denotes the ratio is relative to 0.775V RMS.

DI(Direct Injection) the practice of connecting an electronic musical instrument directly to the input of

the mixing console, rather than to an amplifier and loudspeaker which is covered
by a microphone feeding the console.

Equaliser a device that allows the boosting or cutting of selected bands of frequencies in the

signal path.

Foldback a feed sent back to the artistes via loudspeakers or headphones to enable them to

monitor the sounds they are producing.

Frequency Response the variation in gain of a device with frequency.
(sub) Group an output into which a group of signals can be mixed.
Headroom the available signal range above the nominal level before clipping occurs.
Highpass Filter a filter that rejects low frequencies.
Line Level Signals at a nominal level of -10dBV to +6dBu, coming from a low impedance source.
Noise Gate an electronic switch which only passes signals exceeding a set threshold level.
Pan (pot) abbreviation of ’panorama’: controls levels sent to left and right outputs.
Patchbay a connection panel providing access to most input/output signals on the console,

allowing the operator to redirect or rearrange internal a nd external connections using
flexible patch cords.

Peaking an equaliser response curve affecting only a band of frequencies i.e. based on a

bandpass response.

PFL (Pre-fade Listen) a function that allows the operator to monitor the pre-fade signal in a channel

independently of the main mix.

Rolloff a fall in gain at the extremes of the frequency response.
Shelving an equaliser response affectin g all frequenc ies a bove or b elow the break frequency

i.e. a highpass or lowpass derived response.

Spill acoustic interference from other sources.
Talkback the operator speaking to the artistes or to tape via the auxiliary or group outputs.

46 Appendices