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 every 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.
The GB2’s 6 Auxiliary sends (Fig. 3) are pre fade (1 & 2), pre/post
selectable (3 & 4) and post fade (5 & 6).
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). On the GB2, the signal can be routed to the L-R mix, and
Groups 1&2 and 3&4 (Fig. 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
A 4-segment LED display on each GB4/8 fader strip provides an
instant reference for the signal level on that channel. The GB2 features
peak and signal leds.
STEREO INPUT MODULE
The stereo inputs (2 on the GB2/4, 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.
GB2 Stereo Return
The stereo inputs on the GB2 can be switched for mic + stereo return,
or line.
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 Mono
Input Channel
GB4 Stereo
Input Channel
GB4 Outputs & Master
Fig.1 GB8 Channel strip
detail, Auxiliary
Controls.
Fig.2 GB8 Channel strip
detail, Fader
section.
Fig.3 GB2 Channel strip
detail, Auxiliary
Controls.
Fig.4 GB2 Channel strip
detail, Fader
section.
GB8, GB4 & GB2 INPUTS GB4 OUTPUTS & MASTER