Soundcraft GB2R-12.2, GB2R-16 User Manual

Soundcraft Registered Community Trade Mark/RTM No. 000557827

SOUNDCRAFT
HARMAN INTERNATIONAL INDUSTRIES LTD.,
CRANBORNE HOUSE, CRANBORNE ROAD
POTTERS BAR, HERTS, EN6 3JN, UK
T: [phone]
F: [phone]
E: [e-mail]

SOUNDCRAFT USA
8500 BALBOA BLVD.
NORTHRIDGE, CA 91329, USA
T: [phone]
F: [phone]
E: [e-mail]

www.soundcraft.com

Soundcraft reserves the right to improve or otherwise alter any
information supplied in this document or any other documentation
supplied hereafter. E&OE 12/07
This equipment complies with the EMC Directive 89/336/EEC

Part No: ZL0627-04

TYPICAL SPECIFICATIONS

Frequency Response Mic/Line Input to any output, 20Hz - 20kHz ...................................... <1dB

THD + N Mic sens. -30dBu, +20dBu at all outputs @1kHz.......................... <0.006%

Noise Measured RMS, 22Hz to 22kHz Bandwidth

Mic E.I.N. @ unity gain,150Ω source impedance ........................... -128dBu

Mix Output, 40 inputs routed to mix .............................................. <-82dBu

Group & Centre Outputs ................................................................ <-83dBu

Aux Outputs (GB2 Groups only) ..................................................... <-80dBu

Matrix Outputs............................................................................... <-89dBu

Crosstalk Input Channel Mute......................................................................... <-97dB

(@1kHz, typical) Input Fader cut-off........................................................................... <-95dB

Pan isolation ................................................................................... <-75dB

Mix route isolation........................................................................... <-97dB

Group route isolation....................................................................... <-97dB

Adjacent channel crosstalk.............................................................. <-99dB

Group to Mix.................................................................................... <-84dB

Aux Send pots offness (typical) ....................................................... <-84dB

Matrix Send pots offness (typical) ................................................... <-84dB

CMRR Typical @ 1kHz .................................................................................... 80dB

PLEASE NOTE: GB2R noise, crosstalk and CMRR specifications exceed the standard GB Series
specifications, please check the website for full details

Input & Output Mono & Stereo Mic Inputs.............................................................. +15dBu

Max Levels Mono & Stereo Line Inputs ............................................................. +30dBu

Stereo Returns & Insert Returns ..................................................... +20dBu

Any output ...................................................................................... +20dBu

Nominal Operating Level ..................................................................... 0dBu

Headphone Power.................................................... 2 x 250mW into 200Ω

Input & Output Mic Inputs ............................................................................................ 2kΩ

Impedances Line Inputs and Stereo Returns .......................................................... 10kΩ

Input channels Insert Return ....................... 5kΩ with EQ in, otherwise 3kΩ

Mix, Group, Aux, Matrix & Direct outputs............................................ 150Ω

Insert sends ........................................................................................ 75Ω

Recommended Headphone Impedance .................................... 100 - 600Ω

High pass filter (Mono input) .........................................................................100Hz, 18dB per octave

EQ (Mono input) HF ....................................................... 13kHz, +/-15dB, 2nd order shelving

Hi-Mid......................................................... 550Hz-13kHz, +/-15dB, Q=1.5

Lo-Mid ......................................................... 80Hz-1.9kHz, +/-15dB, Q=1.5

LF.......................................................... 80Hz, +/-15dB, 2nd order shelving

EQ (Stereo input) HF ....................................................... 13kHz, +/-15dB, 2nd order shelving

Hi-Mid ................................................................... 2.5kHz, +/-15dB, Q=0.8

Lo-Mid ................................................................... 450Hz, +/-15dB, Q=0.8

LF.......................................................... 80Hz, +/-15dB, 2nd order shelving

Metering Input channels (GB4/GB8) ......... Single tri-colour 4-segment LED bargraph

Outputs (GB4) ................................ 7 tri-colour 12-segment LED bargraphs

Outputs (GB8) ............................. 11 tri-colour 12-segment LED bargraphs,

+ Meterpod with 3 VU meters (L/R/C)

Outputs (GB2/GB2R) ................ 2 tri-coloured 12-segment LED bargraphs,

(indicates monitor source level)

Power consumption AC mains supply (internal PSU) 85V-270V AC,

50/60Hz universal input

Power consumption............................................................ Less than 150W

Operating conditions Temperature range............................................................. -10ºC to +30ºC

Relative humidity........................................................................ 0% to 80%

GRAHAM BLYTH

Graham Blyth, Soundcraft’s co-founder and Technical

Director, has taken the well established and classic

Soundcraft microphone preamplifier to a new level of

performance, resulting in the new GB30 preamp which

boasts extraordinary clarity with exceptionally controlled

overload characteristics.

Soundcraft’s legendary 4-band EQ has also been

improved further with the addition of elements derived

from Soundcraft’s highly successful MH Series consoles.

This new design delivers the sound of the classic ‘British

EQ’ enhanced even further with more focused HF and LF

shelving sections.

Note: These figures are typical of performance in a normal electromagnetic environment and are often exceeded. Performance may be
degraded in severe conditions.All measurements refer to electronically balanced inputs and outputs.

PROFESSIONAL

MIXING CONSOLES

THE FULLY PROFESSIONAL LIVE SOUND CONSOLE
YOU THOUGHT YOU COULDN’T AFFORD

Drawing on 30 years of Soundcraft

experience, GB Series consoles set new

standards in professional live sound mixing

on a budget. The GB8 (8-bus) console is

packed with the features you need to create

a memorable FOH and monitor mix,

combining totally re-engineered circuit

topology with our ground-breaking GB30 mic

preamp and EQ designs to deliver a sonic

performance rivalling many high-price, high-

end consoles.

The GB8 has plenty of bus power for

sophisticated mixing applications. All eight

Aux master controls can be swapped

with eight Groups, and all Auxes

are pre/post switchable globally

per Aux bus from the Master

Section. In addition to the eight

Groups, the GB8 has L/C/R and

eight Aux busses. Four mute

groups provide quick and easy muting

of groups of channels, ideal for scene

changes or where groups of instruments

need to be silenced. And the output matrix is

essential when different zones in a venue

require specifically tailored mixes,

enabling the operator to create

sub-mixes of the Group, L-R

mix and C (mono) busses.

Unlike other mixers in their

class, GB Series consoles

are built to last with a rigid

steel chassis, high quality

vertically mounted PCB channel

strips and individually nutted potentiometers

ensuring reliability in both fixed installations

and on the road.

And because Soundcraft understands

the way that live sound

engineers work, you’ll find

an intuitive control

surface and a

conveniently angled

rear connector

panel, so you can do

all your patching

without ever leaving the

mix position.

GB8 FEATURES:

• 16, 24, 32, 40 and 48 channel frame sizes

• 19 busses

• 4 full feature stereo channels

• 4 stereo returns

• 8 Aux sends (all are pre/post

switchable)

• 8 sub groups (SWAP with all 8 Auxes)

• 11x4 output matrix

• Record output with limiter

• Alternate stereo output with limiter

• 1kHz oscillator

• Meterpod with 3 high definition LED VU

meters (L/C/R)

• Internal jumpers switch pre-fade Aux sends

to pre-EQ

• GB30 mic preamp and precision

equalisation circuitry

• Direct outputs on every channel

• Talkback facility

• 100mm faders

• Switchable 48V phantom powering on every

channel

• 18dB/octave high pass filter

• 4 mute groups

• 12-segment LED metering

With dual-mode topology derived from

Soundcraft’s acclaimed MH Series, the GB8

and GB4 consoles provide ideal live sound

mixing solutions for medium-sized venues

including clubs, theatres and houses of

worship. With a single button press on the

GB4 (4-bus), any of the first four Aux master

controls can be swapped with the

respectively numbered Group fader, providing

the flexibility to work at FOH, Monitors, or

perform both duties simultaneously.

The GB4 has L/C/R and eight Aux busses in

addition to its four groups and, like the GB8,

there are four mute groups and an output

matrix for creating zoned mixes.

Like all GB series mixers, the GB4 uses

GB30 mic preamps which use local

linearisation techniques rather than global

feedback to deliver an extremely open

frequency response and excellent phase

linearity. The GB30 EQ borrows the innovative

designs developed for the Soundcraft MH4

console, providing GB users with the benefits

of genuine high-end equalisation. And thanks

to a meticulous ‘ground-up’ approach to

circuit and mechanical design, the GB Series

exhibits class-leading noise performance and

channel isolation figures.

When it comes to recording a performance,

the GB4 & GB8 are similarly well equipped

with pre-/post-fader switchable direct

outputs on every channel and a high-quality

limiter on dedicated record outputs fed from

the L-R mix bus.

GB4 FEATURES:

• 12, 16, 24, 32 and 40 channel frame sizes

• 15 busses

• 2 full feature stereo channels

• 2 stereo returns

• 8 Aux sends (4 are pre/post switchable)

• 4 sub groups (SWAP with Auxes 1-4)

• 7x4 output matrix

• Record output with limiter

• GB30 mic preamp and precision equalisation

circuitry

• Direct outputs on every channel

• Talkback facility

• 100mm faders

• Switchable 48V phantom powering on every

channel

• 18dB/octave high pass filter

• 4 mute groups

• 12-segment LED metering

Dedicated record outputs with a high-quality

limiter are fed from the L-R mix bus.

DUAL-MODE TOPOLOGY,
STRAIGHT FROM THE SOUNDCRAFT MH SERIES

Available in 16, 24 and 32 channel

configurations, the GB2 is designed for

installed sound and A/V applications that

don’t require all the sophisticated

functionality of the GB4 and GB8. However

the GB2 is a genuine GB Series console in

every respect, with sound quality assured by

GB30 Mic Pre and Equaliser designs, and

reliability by the same rugged build quality

that has made the GB4 and GB8 so

dependable in demanding professional

applications.

Along with six Aux busses and an integral

6 x 2 matrix, four subgroups are provided as

two stereo pairs, with a unique facility for

adjusting the width of the stereo signal

across the stereo mix. The channel pan

settings are retained on the group outputs,

while the degree of stereo separation to the

mix bus is independently adjustable from full

stereo through to mono.

The GB2 also features two stereo input

channels, with separate mic and line inputs.

In normal use, the mic inputs are routed to

the local channel and the line inputs act as

a stereo return to the mix bus. Selecting the

line input to the local channel overrides the

mic inputs.

GB2 FEATURES:

• 16, 24, 32 channel frame sizes

• 12 busses

• 2 full feature stereo channels

• 2 stereo returns (on stereo channels)

• 6 Aux sends

• 4 sub groups (paired)

• 6x2 output matrix

• GB30 mic preamp and precision equalisation

circuitry

• Direct outputs on every mono channel

• Talkback facility

• 100mm faders

• Switchable 48V phantom powering on every

channel

• 100Hz high pass filter

• 12-segment LED metering

• Record output

Line inputs on the stereo channels can also

act as a stereo return.

SMALLER SCALE MIXING,
WITHOUT THE COMPROMISES

GB MIXING POWER IN A COMPACT
RACK-MOUNTING FORMAT

With a convenient, rack-mountable format,

the GB2R packs GB Series features and

sound quality into a compact mixer, ideal for

use in fixed installations or a touring rack.

Available in 12 mono/2 stereo channel

(GB2R 12/2) or 16 mono channel (GB2R

16) versions, the versatility of the GB2R is

enhanced by a rotatable connector pod for

top or rear cable entry, enabling use in a

variety of mounting configurations.

Both models feature the same GB30 Mic Pre

and Equaliser designs found in all GB

mixers, ensuring exceptional sound quality.

In addition, there are six Aux busses,

switchable phantom power on every mic

input and direct outputs for every channel.

Precision output level control is facilitated by

dual faders on the master stereo output,

and for capturing live performances phono

connectors provide a high-quality direct

recording solution.

Patching in outboard processors is made

simple by two Stereo Returns with level

controls to Mix or Sub Group Outputs (12/2

version only) and to Aux 1 & 2.

In addition to a stereo sub group, the GB2R

12/2 adds two fully-featured stereo input

channels, each with two Mic inputs and

separate Line inputs, switchable direct to Mix

as another effects return, or into the local

channel (overriding the Mic input).

GB2R FEATURES:

• 19" rack-mountable or tabletop mixer

• 12/2 channel version with 12 mono inputs

and 2 stereo inputs, stereo Sub Group

Output, Mix and Mono Sum Outputs – total

inputs to mix 26

• 16 channel version with 16 mono inputs,

Stereo Mix and Mono Sum outputs – total

inputs to mix 22

• 8 (GB2R 16) or 10 (GB2R 12/2) busses

• 2 stereo inputs (GB2R 12/2 only)

• GB30 mic preamp and precision equalisation

circuitry

• 6 Aux Outputs

• Direct Outputs on every mono channel

• 100mm faders

• Switchable +48V phantom power on every

mic input

• 100Hz high pass filter

• 12-segment LED metering

• Internal switched mode power supply

• Record output

Rear connector panel can be rotated to

facilitate use on a desktop or in a rack.

MONO INPUT MODULE

Mic Input

A balanced XLR connector accepts balanced or unbalanced mic
signals.

Line Input

A balanced 1/4" jack accepts balanced or unbalanced line level
sources, such as keyboards.

+48V Phantom Power

Phantom power is individually switchable on every channel, with front
panel LED indication of status.

Phase Reverse

Phase reverse is individually switchable on ever y channel.

Input Stage

Precision, low noise mic preamps deliver continuously variable gain
between 5B and 60dB.A Peak LED indicates internal signal levels in
excess of +18dBu.

High Pass Filter

A steep 18dB per Octave High Pass Filter is included straight after the
preamp to reduce low frequency rumble on stage and clean up vocal
performances.

Insert

A pre-fade, pre-EQ (but post-HPF) insert point is provided for patching
in Limiters, Graphic Equalisers or other signal processors. It may also
be used for recording.

Direct Output

A direct output is also available on every mono channel with individual
pre/post fader switching situated on the rear panel. This allows the
direct outputs to be equally useful for effects send applications or
multitrack tape feeds.

EQ Section

GB Series consoles incorporate the GB30 4-band equaliser section ­based on that used in the high-end MH Series. Both the HF and LF
shelving sections have steeper slopes than usual which substantially
reduces mid frequency harshness in the HF band and muddiness in the
LF. This increase in “cleanliness” of response is further enhanced by an
element of undershoot and overshoot in the boost/cut response. It has
two swept mid frequencies carefully selected for optimum control
during live performances. All bands provide 15dB of cut or boost. The
Low frequency equaliser response shelves at 80Hz. The swept Lo Mid
control operates between 80Hz and 1.9kHz. The swept Hi Mid control
operates at frequencies between 550Hz and 13kHz. The fixed High
frequency equaliser response shelves at 13kHz.

EQ Switch

The EQ section can be bypassed using the EQ switch, allowing comparison
of treated and untreated sounds without having to reset controls.

Auxiliary Sends

The 6 Auxiliary sends are pre fade (1 & 2), pre/post selectable (3 & 4)
and post fade (5 & 6).

Level Control and Routing

On the GB2R the signal can be routed to the Stereo Mix and the Sub
Group (12/2 model only). For GB2, the signal can be routed to the
Stereo Mix, and Groups 1&2 and 3&4.

Pan

Turning the pan control full left or right enables odd or even groups or
the left or right Mix bus to be accessed individually.

Solo/PFL

Each channel can be soloed pre-fader, post-EQ to check levels. PFL
status is indicated via a front panel LED.

100mm Fader

Professional grade, 100mm faders provide accurate, consistent control
of audio levels and have superb cut-off performance.

Metering

Both GB2 and GB2R input channels feature peak and signal leds.

STEREO INPUT MODULE - GB2 and GB2R 12/2 only

The 2 stereo inputs allow connection of stereo sources, or use as
sophisticated effects returns. The stereo input channels share all
features with the mono input channels, with the exception of the
following:

Connections

Each channel is equipped with both balanced jack and XLR pairs. The
left or right input can be selected, if required, as a single, mono source
to be routed to both paths. Alternatively both the left and right signals
can be mono-summed.

EQ Section

The equaliser section provides 15dB of cut or boost at each of
4-bands: a HF shelf at 13kHz; Hi-Mid at 2.5kHz; Lo-Mid at 450Hz; and
a LF shelf at 80Hz.

Stereo Return

When the XLR/Mic input is selected to the channel, the Line input can
be switched to mix as an effects return or as another input to mix.
When the Line input is switched to the channel, the XLR/Mic input is
disconnected.

MONO INPUT MODULE

Mic Input

A balanced XLR connector accepts balanced or unbalanced mic
signals.

Line Input

A balanced 1/4" jack accepts balanced or unbalanced line level
sources, such as keyboards.

+48V Phantom Power

Phantom power is individually switchable on every channel, with front
panel LED indication of status.

Phase Reverse

Phase reverse is individually switchable on ever y channel.

Input Stage

Precision, low noise mic preamps deliver continuously variable gain
between 5dB and 60dB.A Peak LED indicates internal signal levels in
excess of +18dBu.

High Pass Filter

A steep 18dB per Octave High Pass Filter is included straight after the
preamp to reduce low frequency rumble on stage and clean up vocal
performances.

Insert

A pre-fade, pre-EQ (but post-HPF) insert point is provided for patching
in Limiters, Graphic Equalisers or other signal processors. It may also
be used for recording.

Direct Output

A direct output is also available on every mono channel with individual
pre/post fader switching situated on the rear panel. This allows the
direct outputs to be equally useful for effects send applications or
multitrack tape feeds.

EQ Section

GB Series consoles incorporate the GB30 4-band equaliser section ­based on that used in the high-end MH Series. Both the HF and LF
shelving sections have steeper slopes than usual which substantially
reduces mid frequency harshness in the HF band and muddiness in the
LF. This increase in “cleanliness” of response is further enhanced by an
element of undershoot and overshoot in the boost/cut response. It has
two swept mid frequencies carefully selected for optimum control
during live performances. All bands provide 15dB of cut or boost. The
Low frequency equaliser response shelves at 80Hz. The swept Lo Mid
control operates between 80Hz and 1.9kHz. The swept Hi Mid control
operates at frequencies between 550Hz and 13kHz. The fixed High
frequency equaliser response shelves at 13kHz.

EQ Switch

The EQ section can be bypassed using the EQ switch, allowing comparison
of treated and untreated sounds without having to reset controls.

Auxiliary Sends

The GB4 has 8 flexible Auxiliary sends which allow the choice of either
monitor or effects orientated mixes. Auxes 1-4 are pre-fader and, in
normal operation, are routed to the rotary Aux masters 1-4. In SWAP
mode, they are routed to Group faders 1-4 and Group meters 1-4, ideal
for monitor mixing applications. Auxes 5 to 8 are pre/post switchable ­globally assigned selectable per Aux bus from the Master Section.

The GB8’s 8 Auxiliary sends (Fig. 1) are globally selectable per Aux bus
between pre/post fade. The Auxes are routed to rotary Aux masters,
which all feature SWAP mode.

Level Control and Routing

On the GB4, the signal on each fader can be routed to the L-R mix (via
the Pan control), the C (mono) bus and Groups 1&2 and 3&4. On the
GB8, the signal can additionally be routed to Groups 5&6 and 7&8
(Fig. 2).

Pan

Turning the pan control full left or right enables odd or even groups or
the left or right Mix bus to be accessed individually.

Solo/PFL

Each channel can be soloed pre-fader, post-EQ to check levels. PFL
status is indicated via a front panel LED.

100mm Fader

Professional grade, 100mm faders provide accurate, consistent control
of audio levels and have superb cut-off performance.

Metering

A 4-segment LED display on each GB4/8 fader strip provides an
instant reference for the signal level on that channel.

STEREO INPUT MODULE

The stereo inputs (2 on the GB4, 4 on the GB8) allow connection of
stereo sources, or use as sophisticated effects returns. GB8 has four
stereo inputs. The stereo input channels share all features with the
mono input channels, with the exception of the following:

Connections

Each channel is equipped with both balanced jack and XLR pairs. The
left or right input can be selected, if required, as a single, mono source
to be routed to both paths. Alternatively both the left and right signals
can be mono-summed.

EQ Section

The equaliser section provides 15dB of cut or boost at each of 4­bands: a HF shelf at 13kHz; Hi-Mid at 2.5kHz; Lo-Mid at 450Hz; and a
LF shelf at 80Hz.

GB4 Mono
Input Channel

GB4 Stereo
Input Channel

Fig.1 ­GB4/8 Channel
strip detail, Auxiliary
Controls.

Fig.2 ­GB4/8 Channel
strip detail, Fader
section.

Fig.1 ­GB2R 12/2 Mono
channel fader
panel.

Fig.2 ­GB2R 16 Mono
channel fader
panel.

Fig.3 ­GB2R 12/2 Stereo
channel input
section.

Fig.4 ­GB2R 12/2 Stereo
channel fader
panel.

GB2
Mono Input
Channel

GB2
Stereo Input
Channel

GB8 & GB4 INPUTS GB2 & GB2R INPUTS

GROUP SECTION

Group Outputs

Each Group has an impedance-balanced XLR output
connector, allowing long cable runs on stage.

Insert Points

Pre-fade insert points are provided on jack
connectors, for the connection of Limiters, Graphic
Equalisers or other signal processors.

Group Metering

GB4 has four 12-segment peak reading bargraph
meters which display Group (or Aux 1-4 in SWAP
mode) output levels.

Matrix Assignment

Four rotary controls per Group allow individual
assignment to Matrices 1-4.

Matrix Masters

The level at each Matrix output (balanced jack) on
the rear panel is controlled by a rotary control, with
a button for AFL.

Auxiliary Masters

The level at each Auxiliary output (balanced jack)
on the rear panel is controlled by a rotary control
with a button for AFL.

Group/Aux SWAP

GB4 has four push buttons which swap the
functions of Auxiliary 1-4 master rotary controls
and Group master faders. NB: The 12-segment
peak reading bargraph meters always display the
signal selected to the Group faders, i.e. Groups in
normal operation, or Auxes when used in SWAP
mode.

Routing

The signal on each Group fader can be routed to
either the L-R mix (via the Pan control) or to the C
(mono) bus.

100mm Group Faders

The Group faders provide 10dB of extra gain above
the zero mark, whilst still ensuring smooth
operation. Each Group is also equipped with AFL.

MASTER SECTION

Connections

L-R mix and C (mono) bus outputs appear on
balanced XLR with jack insert points. The L-R mix is
also provided on two pairs of balanced jack
outputs and one pair of RCA/phono outputs. A
balanced XLR input allows a talkback mic to be
connected. Two control room outputs for engineer
monitoring are available on impedance balanced
1/4" jacks.

2TRK Inputs

A pair of unbalanced -10dBv phono connectors
labelled “2TRK In” allow pre-show music to be
replayed. An independent 2 TRK rotary level control
is also provided.

Rec/Alt Output

GB4 has a single Rec/Alt section. Outputs are
provided on impedance balanced 1/4" jacks and
unbalanced -10dBv phono connectors. They
provide a post-fade send from the L-R mix. The C
(mono) bus may be added and/or the mix can be
mono summed. A rotary control governs level and
a switchable limiter is provided.

Talkback Section

Once connected, the engineer’s talkback mic can
be routed to all Groups and/or Aux 1-2, 3-4, 5-6 &
7-8. A rotary control governs talkback level.

Stereo Returns

GB4 has two stereo returns - provided for use with
effects units, or as simple stereo instrument
inputs. The rotary controls govern level. Ste Ret 1
and 2 can be routed to Groups 1/2 and 3/4
respectively, or the main L-R mix.

CONTROL ROOM SECTION

The control room section allows the engineer to
monitor either the 2-track return, the C (Mono)
Bus, or the Mix via the control room outputs or
headphones. A headphone jack is provided for use
with headphones with impedances of 100 Ohms
or greater. Both the control room and 2-track
return levels can be altered using the associated
controls. It is also possible to replace the Mix
output signal with the 2-track return by pressing “2
TRK TO MIX”.This allows easy playing of pre-show
music at a single button press, without having to
make any alterations to the band’s settings.

Metering

Three 12-segment Peak reading bargraph meters
display L-R mix and C (mono) bus output levels
when the appropriate control room selection is
made. If any input or Auxiliary master is soloed
then the PFL/AFL LED illuminates, and the master
meters show PFL/AFL levels instead.

Matrix Assignment

Any of the four Group masters, Left, Right and C
(mono) buses can be routed to any of the four
matrix outputs via individual rotary controls.

100mm Master Faders

Mix and C (Mono) Output levels are controlled by
custom-built 100mm long throw faders. The Mix
outputs may be routed to the C (Mono) bus should
only a mono PA be required, or an induction loop
need to be fed.

PSU Indicators

A red LED illuminates if the console is powered up,
showing the status of the +/-17v voltage rails.

Integral Power Supply

The console is fitted with a high-efficiency SMPS
design (Switched Mode Power Supply) unit that
makes for cooler operation and lighter weight. The
PSU is capable of accepting a wide range of AC
input voltages without any internal or external
switch changes.An external DPS-3 power supply
may be connected for redundancy operation.

GB4 Outputs & Master

GB4 OUTPUTS & MASTER GB8 OUTPUTS & MASTER

GB8 Outputs & Master

THE GB8 OUTPUTS & MASTER SECTION HAVE THE SAME
FEATURES AS THE GB4, PLUS THE FOLLOWING
PERFORMANCE ENHANCEMENTS.

GROUP SECTION

Group Metering

GB8 has 8 12-segment peak reading bargraph meters which display
Group (or Aux 1-8 in SWAP mode) output levels.

Group/Aux SWAP

GB8 has eight push buttons which swap the functions of Auxiliary 1-8
master rotary controls and Group master faders. NB: The 12-segment
peak reading bargraph meters always display the signal selected to the
Group faders, i.e. Groups in normal operation, or Auxes when used in
SWAP mode.

MASTER SECTION

Rec/Alt Output

GB8 features separate Record and Alternate output sections. Outputs
are provided on impedance balanced 1/4" jacks and unbalanced

-10dBv phono connectors. They provide a post-fade send from the L-R
mix. The C (mono) bus may be added and/or the mix can be mono
summed. A rotary control governs level and a switchable limiter is
provided.

Talkback Section

GB8 additionally features a 1kHz oscillator with identical routing to the
talkback.

Stereo Returns

GB8 has four stereo returns - provided for use with effects units, or
as simple stereo instrument inputs. The rotary controls govern level.
Ste Ret 1, 2, 3 and 4 can be routed to Groups 1/2, 3/4, 5/6 and
7/8 respectively, or the main L-R mix.

TRUE VU METERS

GB8 boasts 3 true VU ballistic (ANSI C16.5) LED meters, which display
the left, right and C (Mono) outputs.The correct classic VU response is
achieved by using 2nd order rectifier filters, not something you see
every day!

GB2 OUTPUTS & MASTER GB2R OUTPUTS & MASTER

GROUP SECTION

Group Outputs

Each Group has an impedance-balanced XLR output
connector, allowing long cable runs on stage.

Insert Points

Pre-fade insert points are provided on jack
connectors, for the connection of Limiters, Graphic
Equalisers or other signal processors.

Group Metering

Selectable 12-segment peak reading bargraph
meters.

Matrix Assignment

One rotary control per Group allows individual
assignment to Matrices 1-2.

Matrix Masters

The level at each Matrix output (XLR) on the rear
panel is controlled by a rotary control, with buttons
for AFL and Mute.

Auxiliary Masters

The level at each Auxiliary output (XLRs 1-4,
balanced jacks 5-6) on the rear panel is controlled
by a rotary control with a button for AFL.

Routing

The signal on each Group fader can be routed to
the L-R mix.

Stereo Width

The channel pan settings are retained on the group
outputs, while the degree of stereo separation to
the mix bus is independently adjustable on rotary
controls from full stereo through to mono.

100mm Group Faders

The Group faders provide 10dB of extra gain above
the zero mark, whilst still ensuring smooth
operation.

MASTER SECTION

Connections

L-R Mix and a mono sum output appear on
balanced XLR with jack insert points on the L-R
outputs. A balanced XLR input allows a talkback
mic to be connected. Two control room outputs for
engineer monitoring are available on impedance
balanced 1/4" jacks. L and R signals may be fed
to each of the 2 matrix busses.

2TRK Inputs

A pair of unbalanced -10dBv phono connectors
labelled “2TRK In” allow pre-show music to be
replayed. An independent 2 TRK rotary level control
is also provided.

Rec Output

Recording outputs are provided on -10dBv phono
connectors. They provide a post-fade send from the
L-R mix.

Talkback Section

Once connected, the engineer’s talkback mic can
be routed to all Groups and/or Auxes.A rotar y
control governs talkback level.

Stereo Returns

Stereo returns are accommodated via the stereo
inputs. These can be switched for simultaneous
mic/stereo return use, or for line inputs (see
inputs).

CONTROL ROOM SECTION

The control room section allows the engineer to
monitor either the 2-track return, Groups 1&2 and
3&4, or the Mix via the control room outputs or
headphones. A headphone jack is provided for use
with headphones with impedances of 100 Ohms
or greater. Both the control room and 2-track
return levels can be altered using the associated
controls. It is also possible to switch the 2-track
return input to Mix, adding to whatever signal is
already present on the mix output, by pressing
“2 TRK TO MIX”. This allows easy playing of
pre-show music at a single button press,
without having to make any alterations to the
band’ssettings.

Metering

12-segment Peak reading bargraph meters can be
selected to display 2-track return, Groups 1&2 and
3&4, or the Mix when the appropriate control
room selection is made. If any input or Auxiliary
master is soloed then the PFL/AFL LED illuminates,
and the master meters show PFL/AFL levels instead.

100mm Master Faders

Output levels are controlled by a 100mm long
throw mix fader.The Mix outputs may be routed to
the C (Mono) bus should only a mono PA be
required, or an induction loop need to be fed.

Integral Power Supply

The console is fitted with a high-efficiency SMPS
design (Switched Mode Power Supply) unit that
makes for cooler operation and lighter weight. The
PSU is capable of accepting a wide range of AC
input voltages without any internal or external
switch changes.An external DPS-3 power supply
may be connected for redundancy operation.

GROUP SECTION - GB2R 12/2 Only

Sub Group Output

The Sub Group has an impedance-balanced XLR
output connector, allowing long cable runs on stage.

Insert Points

Pre-fade insert points are provided on jack
connectors, for the connection of Limiters, Graphic
Equalisers or other signal processors.

Group Metering

Selectable 12-segment peak reading bargraph
meters.

Auxiliary Masters

The level at each Auxiliary output (XLRs 1-4,
balanced jacks 5-6) on the rear panel is controlled
by a rotary control with a button for AFL.

Routing

The signal on the sub group fader can be routed to
the L-R mix, and/or mono-summed.

100mm Group Faders

The Group faders provide 10dB of extra gain above
the zero mark, whilst still ensuring smooth
operation.

MASTER SECTION

Connections

L-R Mix and a mono sum output appear on
balanced XLR with jack insert points on the L-R
outputs. Two control room outputs for engineer
monitoring are available on impedance balanced
1/4" jacks.

2TRK Inputs

A pair of unbalanced -10dBv phono connectors
labelled “2TRK In” allow pre-show music to be
replayed. An independent 2 TRK rotary level control
is also provided.

Auxiliary Masters

The level at each Auxiliary output (XLRs 1-4,
balanced jacks 5-6) on the rear panel is controlled
by a rotary control with a button for AFL.

Rec Output

Recording outputs are provided on -10dBv phono
connectors. They provide a post-fade send from the
L-R mix.

Stereo Returns

Two stereo returns are available with Level controls
to Mix, Aux 1 and Aux 2, and on the 12/2 model to
sub group.

CONTROL ROOM SECTION

The control room section allows the engineer to
monitor either the 2-track return, Mix or Sub
Groups (12/2 model only) via the control room
outputs or headphones. A headphone jack is
provided for use with headphones with
impedances of 100 Ohms or greater. Both the
control room and 2-track return levels can be
altered using the associated controls. It is also
possible to switch the 2-track return input to Mix,
adding to whatever signal is already present on the
mix output, by pressing “2 TRK TO MIX”. This allows
easy playing of pre-show music at a single button
press, without having to make any alterations to
the band’s settings.

Metering

12-segment Peak reading bargraph meters can be
selected to display 2-track return, Mix or Sub
Group (12/2 model only) when the appropriate
control room selection is made. If any input or
Auxiliary master is soloed then the PFL/AFL LED
illuminates, and the master meters show PFL/AFL
levels instead.

100mm Master Faders

Output levels are controlled by dual 100mm long
throw mix faders.

Integral Power Supply

The console is fitted with a high-efficiency SMPS
design (Switched Mode Power Supply) unit that
makes for cooler operation and lighter weight. The
PSU is capable of accepting a wide range of AC
input voltages without any internal or external
switch changes.

GB2R 12/2 Outputs & Master GB2R 16 Outputs & Master

GB2 Outputs & Master

GB4 SYSTEM BLOCK DIAGRAM GB8 SYSTEM BLOCK DIAGRAM

GB2R

OVERHEAD VIEW

REAR PANEL CONNECTIONS

GB8/GB4/GB2

OVERHEAD VIEW

REAR PANEL CONNECTIONS

TOP PANEL, CONNECTORS, DIMS & WEIGHTS

NB: GB8 32 channel
model shown.

NB: GB8 32 channel
model shown. GB4 and
GB2 Channel and
Outputs & Master section
differences are
highlighted in the
preceding pages.

*NB The Meterpod is only available on the GB8

235mm (9.23")*

159mm (6.26")

10mm (0.39")

656mm (25.83")

GB8

Frame Size Width Weight

16 Ch 984mm (38.74") 25kg (55.1lbs)
24 Ch 1208mm (47.56") 30kg (66.1lbs)
32 Ch 1442mm (56.77") 35kg (77.2lbs)
40 Ch 1666mm (65.59") 40kg (88.2lbs)
48 Ch 1889mm (74.37") 45kg (99.2lbs)

GB4

Frame Size Width Weight

12 Ch 730mm (28.73") 20kg (44.1lbs)
16 Ch 842mm (33.13") 22kg (48.5lbs)
24 Ch 1065mm (41.93") 27kg (59.5lbs)
32 Ch 1300mm (51.17") 32kg (70.5lbs)
40 Ch 1523mm (59.96") 37kg (81.6lbs)

GB2

Frame Size Width Weight

16 Ch 790mm (31.10") 22kg (48.5lbs)
24 Ch 1013mm (39.88") 25kg (55.1lbs)
32 Ch 1247mm (49.09") 30kg (66.1lbs)

GB2/GB2R SYSTEM BLOCK DIAGRAMS

PEAK

IDENTICAL FOR
GROUPS 3 - 4(GB2)

1-2

SUB

GB2R12-2

GB2

GRP 1 - 4

IDENTICAL FOR
GROUPS 3 - 4(GB2)

1-2

MIC

LINE

INS

+48

MIC+

MIC-

LINE+

LINE-

-20dB

INS SEND

INS RETN

GAIN

5-60dB

100Hz

HFH MIDL MIDL F

PEAK

EQ

DEFAULT

AUX PRE MODE

POST/PRE EQ

MUTE

FADER

SIGNAL

PRESENT

+10dB

PFL

AUX1

+6

AUX2

+6

AUX3

+6

AUX4

+6

3 - 4

PRE

AUX5

+6

AUX6

+6

DEFAULT

AUX 5 - 6 MODE:
POST OR FOLLOW
AUX 3 - 4

PAN

R

L

SUB

MIX

AUX1

+6

AUX2

+6

AUX3

+6

AUX4

+6

3 - 4

PRE

AUX5

+6

AUX6

+6

DEFAULT

AUX 5 - 6 MODE:
POST OR FOLLOW
AUX 3 - 4

MIX

AUX 1 - 6

SUB L-R

MIX L - R

PFL/AFL

SOLO EN

DIRECT

PRE

MONO INPUT

STEREO INPUT (NOT GB2R 16)

+48

MIC GAIN

5-60dB

MIC L

LINE TO MIX/
LINE TO CHAN

LINE L

MIC+

MIC-

LINE+

LINE-

MIC+

MIC-

MIC R

LINE R

LINE+

LINE-

MONOL

SIGNAL
PRESENT

-17

-7

-17

-7

+17

+17

HFH MIDL MIDL F

EQ

MUTE

PFL

+10dB

+10dB

R

(ON REAR CON)

LINE

FADER

BAL

HFH MIDL MIDL F

GB2R12-2

(GB2R 12-2)

GB2

(GB2)

DIMENSIONS & WEIGHTS

445mm (17.52")

80mm (3.15")

57mm (2.24")

Rear connector panel rotated

for rack mounting

GB2R

Width Weight

GB2R 12/2 483mm (19") 12.5kg (27lbs)

with rack ears

440mm (17.32")
without rack ears

GB2R 16 483mm (19") 12.5kg (27lbs)

with rack ears

440mm (17.32)
without rack ears

190mm (7.48")

NB: GB2R 16 shown.

NB: GB2R 12/2
shown.

SUB L-R

SOLO EN

AUX 1 - 6

MIX L - R

PFL/AFL

GRP 1 - 4

MIX OUT L - R

SUB OUT L-R

AUX 2, 4, 6 AS BELOW

+16dB

AUX 1

INV

AFL

INV

SUBL

INSERT

INV

SUBR

INSERT

INV

GRP1

INSERT

PFL

INV

GRP2

INSERT

PFL

INV

INV

AUX 1

OUT

SUBL

+10dB

MIX

MONO

SUBR

+10dB

GRP1

+10dB

MIX

GRP2

+10dB

GROUPS 3, 4

AS ABOVE

+10dB

MIX
FDR

MIX L
INSERT

+10dB

MIX R
INSERT

+16dB

AUX 3

INV

AFL

GRP1

OUT

WIDTH

GRP2

OUT

MIX L
OUT

MIX R
OUT

AUX 3

OUT

SUB L

OUT

SUB R

OUT

MONO
OUT

MNTR L

MNTR R

H/PHONES

AUX 5

AFL

INV

+16dB

INV

SOLO ENABLE

GRPSAUX 1-4

PFL/AFL

AUX 5

OUT

TB GAIN

TB MIC

+6dB

C/RM

LVL

+6dB

+20dB

+20dB

READING

PHNS

RECTIFIER

LVL

MNO

SWITCH FITTED

ON GB2R 12-2

TO AUX 1 FOR STEREO RET 1
TO AUX 2 FOR STEREO RET 2

AFL

MIX

LR

+18 +18

-20 -20

PEAK

PEAK
READING
RECTIFIER

MIX

SUB

LINKS FITTED

ON GB2R 16

+16dB

INV

MATRIX 1

LEVEL

STEREO RTN 2

AS ABOVE

MATRIX

MUTE

OUT

MATRIX 2 AS ABOVE

+18dB

LEVEL

+18dB

AUX 1
PRE

2 TK L

2TK

2 TK R

2TRK

300mV

300mV

STE RET 1 L

STE RET 1 R

GRP1

GRP2 +6

GRP3

GRP4

MIXL

MIXR

REC L

REC R

1-2

3-4

MIX

SUB

GRP OUT 1-4

+6

+6

+6

+6

+6