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Allen and Heath
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GL-4800
Owners manual
62 pgs12.6 Mb0

Allen and Heath GL-4800 Owners manual

ALLEN&HEATH
GL4800
USER GUIDE
Publication AP6150
Limited One Year Warranty
This product is warranted to be free from defects in materials or workmanship for a period of one year from the date of purchase by the original owner.
To ensure a high level of performance and reliability for which this equipment has been designed and manufactured, read this User Guide before operating. In the event of a failure, notify and return the defective unit to Allen & Heath Limited or its authorised agent as soon as possible for repair under warranty subject to the following conditions
Conditions Of Warranty
1. The equipment has been installed and operated in accordance with the instructions in this User Guide
2. The equipment has not been subject to misuse either intended or accidental, neglect, or alteration other than as described in the User Guide or Service Manual, or approved by Allen & Heath.
3. Any necessary adjustment, alteration or repair has been carried out by Allen & Heath or its authorised agent.
4. This warranty does not cover fader wear and tear.
5. The defective unit is to be returned carriage prepaid to Allen & Heath or its authorised agent with proof of purchase.
6. Units returned should be packed to avoid transit damage.
In certain territories the terms may vary. Check with your Allen & Heath agent for any additional warranty which may apply.
This product has been tested to EN55103 Parts 1 & 2 1996 for use in Environments E1, E2, E3, and E4 to demonstrate compliance with the protection requirements in the European EMC directive 89/336/EEC. During some tests the specified performance figures of the product were affected. This is considered permissible and the product has been passed as acceptable for its intended use. Allen & Heath has a strict policy of ensuring all products are tested to the latest safety and EMC standards. Customers requiring more information about EMC and safety issues can contact Allen & Heath.
NOTE: Any changes or modifications to the console not approved by Allen & Heath could void the compliance of the console and therefore the user’s authority to operate it.
GL4800 User Guide AP6150 Issue 1
Copyright © 2005 Allen & Heath Limited. All rights reserved
Manufactured in the United Kingdom by
ALLEN&HEATH Limited
Kernick Industrial Estate, Penryn, Cornwall, TR10 9LU, UK
http://www.allen-heath.com
2 GL4800 User Guide
Important Safety Instructions
WARNINGS
- Read the following before proceeding :
CAUTION
ATTENTION: RISQUE DE CHOC ELECTRIQUE – NE PAS OUVRIR
Read instructions: Read and retain these safety and operating
instructions for future reference. Adhere to all warnings printed here and on the console. Follow the operating instructions printed in this User Guide.
Do not remove cover: Operate the console with its underside
cover correctly fitted. Disconnect mains power by unplugging the power cord if the cover needs to be removed for setting internal options. Refer this work to competent technical personnel only.
Power sources: Connect the console to a mains power outlet only of
the type described in this User Guide and marked on the rear panel. Use the power cord with sealed mains plug appropriate for your local mains supply as provided with the console. If the provided plug does not fit into your outlet consult your service agent for assistance.
Power cord routing: Route the power cord so that it is not likely
to be walked on, stretched or pinched by items placed upon or against it.
Grounding: Do not defeat the grounding and polarisation means
of the power cord plug. Do not remove or tamper with the ground connection in the power cord.
WARNING: This equipment must be earthed.
Water and moisture:
do not expose the console to rain or moisture or use it in damp or wet conditions. Do not place containers of liquids on it which might spill into any openings.
To reduce the risk of fire or electric shock
Ventilation: Do not obstruct the rear and top ventilation slots or
position the console where the air flow required for ventilation is impeded. If the console is to be operated in a flight case, plinth or other furniture ensure that it is constructed to allow adequate ventilation.
Heat and vibration: Do not locate the console in a place
subject to excessive heat or direct sunlight as this could be a fire hazard. Locate the console away from any equipment which produces heat or causes excessive vibration.
Servicing: Switch off the equipment and unplug the power cord
immediately if it is exposed to moisture, spilled liquid, objects fallen into the openings, the power cord or plug become damaged, during lightning storms, or if smoke, odour or noise is noticed. Refer servicing to qualified technical personnel only.
Installation: Install the console in accordance with the
instructions printed in this User Guide. Do not connect the output of power amplifiers directly to the console. Use audio connectors and plugs only for their intended purpose.
GL4800 User Guide 3
General Precautions
8
Damage To prevent damage to the controls and cosmetics avoid
placing heavy objects on the control surface, scratching the surface with sharp objects, or rough handling and vibration.
Environment Protect from excessive dirt, dust, heat and vibration
when operating and storing. Avoid tobacco ash, smoke, drinks spillage, and exposure to rain and moisture. If the console becomes wet, switch off and remove mains power immediately. Allow to dry out thoroughly before using again.
Cleaning Avoid the use of chemicals, abrasives or solvents. The
control panel is best cleaned with a soft brush and dry lint-free cloth. The faders, switches and potentiometers are lubricated for life. The use of electrical lubricants on these parts is not recommended. The fader and potentiometer knobs may be removed for cleaning with a warm soapy solution. Rinse and allow to dry fully before refitting them.
Lifting To avoid injury to yourself or damage to the equipment take
care when lifting, moving or carrying the console.
Transporting The console may be transported as a free-standing unit
or mounted in a purpose built flight case. We recommend that the console is surrounded by shock absorbent foam to protect it from damage during transit. Always use adequate packing if you need to ship the unit. Protect the controls to avoid damage when moving the console.
Hearing To avoid damage to your hearing do not operate any sound
system at excessively high volume. This also applies to any close-to-ear monitoring such as headphones and IEM transducers. Continued
2
exposure to high volume sound can cause frequency selective or wide range hearing loss.
Important Mains plug wiring instructions.
The console is supplied with a moulded mains plug fitted to the AC mains power lead. Follow the instructions below if the mains plug has to be replaced. The wires in the mains lead are coloured in accordance with the following code:
TERMINAL
European USA/Canada
L LIVE BROWN BLACK
N NEUTRAL BLUE WHITE
E EARTH GND GREEN & YELLOW GREEN
The wire which is coloured Green and Yellow must be connected to the terminal in the plug which is marked with the letter E or with the Earth symbol. This appliance must be earthed.
The wire which is coloured Blue must be connected to the terminal in the plug which is marked with the letter N.
The wire which is coloured Brown must be connected to the terminal in the plug which is marked with the letter L.
WIRE COLOUR
Ensure that these colour codes are followed carefully in the event of the plug being changed.
4 GL4800 User Guide
Introduction
Welcome to the Allen & Heath GL4800, the latest generation of the popular GL series of multi-function audio mixing consoles. We have tried to keep this user guide brief and to the point. Please read it fully before starting. Included is information on installing, connecting and operating the console, panel drawings, system block diagram, technical specification and cue sheets. For further information on the basic principles of audio system engineering, please refer to one of the specialist publications and resources available from bookshops, audio equipment dealers and the Internet.
Whilst we believe the information in this guide to be reliable we do not assume responsibility for inaccuracies. We also reserve the right to make changes in the interest of further product development.
We are able to offer further product support through our world-wide network of approved dealers and service agents. You can also access our Web site on the Internet for information on our full product range, our company pedigree, assistance with your technical queries, our contact details or simply to chat about matters audio. To help us provide the most efficient service please keep a record of your console serial number, and date and place of purchase to be quoted in any communication regarding this product.
www.allen-heath.com
Contents
Warranty ................................................ 2
General Precautions.............................. 4
Introduction to this Guide...................... 5
Front Panel Layout ................................ 6
Range and Options ...............................7
Introducing the
Dimensions and Weights ....................10
Specifications ......................................11
System Block Diagram........................ 12
Connectors .......................................... 14
Earthing ...............................................17
Connecting Power............................... 18
GL4800....................... 8
LR Section............................................26
Mono and Master Section ................... 27
The Mute System................................. 30
Mute Groups ........................................ 32
Mute Safes ...........................................35
Mute Snapshots................................... 36
The Snapshot Display .........................37
Solo-In-Place .......................................40
Solo Safes............................................ 41
MIDI......................................................42
Technical Support ...............................46
Front-of-House Application .................48
Matching the Signal Levels .................19
Mono Input Channel............................ 20
Stereo Input Channel .......................... 22
Stereo Channel Applications............... 23
Group Section .....................................24
On-Stage Monitor Application............. 52
Multi-Speaker System Application ......55
Internal Link Options ...........................56
Cue Sheets ..........................................57
GL4800 User Guide 5
0dB 20
-10 10
LINE
MIC
6
-14
30
20
2kHz3k20kHz
-15
1k
700
500Hz
-15
60
45
35Hz
-15 +15
20Hz50200Hz
-15 +15
ODD
LR
+48V
POLARITY
MIC LINE
PAD
10
30
40
GAIN
50
40dB
60
50Hz
HPF
100
200
400HzOFF
7kHz
10k
HF
+15
Q
3k
5k
7k
15k
HM
+15
Q
180Hz
300
450
1kHz
LM
100Hz
150
LF
EQ IN
AUX
1
0dB
PK!
+6
+6
0
AUX
SIG
2
0dB
+6
AUX
3
0dB
+6
AUX
4
0dB
+6
POST PRE
MTX
AUX
TO AUX1
5
0dB
+6
AUX
6
0dB
+6
AUX
7
0dB
+6
AUX
8
0dB
+6
POST PRE
AUX
9
0dB
+6
AUX
AUX
10
10
0dB
0dB
+6
+6
POST PRE
=
PAN
EVEN
LAMP LAMP
GL4800
MULTI FUNCTION AUDIO MI XING CONSOLE
POST PRE
-15
-20
-10
-30
-5
0dB
ENABLE
1
+16
+9
+6
+3
0
-3
-6
-9
-12
-15
-20
-30
FOLLOW SML FADER
MUTE
SAFE/PREVIEW
AFL
10
5
0
5
10
20
30
1
GRP REV GRP REV GRP REV G RP REV GRP REV GRP REV GRP REV GRP REV L REV R REV
TB TO AUX1
+6
+6
+6
+6
POST PRE
=
L R
POST PRE
-15
OUTPUT
-20
-10
TRIM
-30
-5
0dB
GRP
1
ENABLE
2345678 LRM
+16
+9
+6
+3
0
-3
-6
-9
-12
-15
-20
-30
FOLLOW SML FADER
MUTE
SAFE/PREVIEW
AFL AFL AFL AFL AFL AFL AFL AFL AFL
PK!
10
+6
0
5
SIG
0
5
10
20
30
MTX
2
TO AUX2
TB TO AUX2
MTX
1
0dB
+6
MTX
2
0dB
+6
MTX
3
0dB
+6
MTX
4
0dB
GRP
+6
1
POST PRE
=
PAN
L R
OUTPUT
0dB
0dB
0dB
0dB
POST PRE
-15
-20
TRIM
-30
GRP
2
ENABLE
+16
+9
+6
+3
-10
-5
0dB
0
-3
-6
-9
-12
-15
-20
-30
FOLLOW SML FADER
OUTPUT
-15
-20
TRIM
-30
GRP
3
ENABLE
+16
+9
+6
+3
FOLLOW SML FADER
MUTE
SAFE/PREVIEW
PK!
+6
0
SIG
MTX
3
TO AUX3
MTX
1
MTX
2
MTX
3
MTX
4
GRP
2
PAN
L R
SAFE/PREVIEW
PK!
10
5
0
5
10
20
30
=
10
+6
0
5
SIG
0
5
10
20
30
MTX
4
TO AUX4
TB TO AUX3
MTX
1
0dB
+6
MTX
2
0dB
+6
MTX
3
0dB
+6
MTX
4
0dB
GRP
+6
3
POST PRE
=
PAN
L R
-15
-20
-30
-15
-20
LEV LEV LEV LEV LEV LEV
-10
-30
-5
0dB
ON ON ON ON ON ON
-15
-20
-10
-30
-5
0dB
-15
-20
-10
-5
0dB
-10
-30
-5
0dB
-15
-20
-30
0dB
AFL AFL AFL AFL AFL AFL
OUT REVOUT REVOUT REVOUT REV OUT REVOUT REV
PK!
+6
SIG
SAFE/PREVIEW
0
POST PRE
+16
+9
+6
+3
0
-3
-6
-9
-12
-15
-20
-30
FOLLOW SML FADER
MUTE
10
5
0
5
10
20
30
TB TO AUX9
+6
+6
+6
+6
POST PRE
0dB 0dB
POST PRE
-10
-5
0dB
0
-3
-6
-9
-12
-15
-20
-30
MUTE
TB TO AUX4
+6
+6
+6
+6
POST PRE
OUTPUT
0dB
0dB
0dB
0dB
POST PRE
-15
-20
-10
TRIM
-30
-5
0dB
GRP
4
ENABLE
+16
+9
+6
+3
0
-3
-6
-9
-12
-15
-20
-30
FOLLOW SML FADER
MUTE
SAFE/PREVIEW
PK!
10
+6
0
5
SIG
0
5
10
20
30
TB TO AUX5
MTX
1
+6
MTX
2
+6
MTX
3
+6
MTX
4
GRP
+6
4
POST PRE
=
PAN
L R
OUTPUT
0dB
0dB
0dB
0dB
POST PRE
-15
-20
-10
TRIM
-30
-5
0dB
GRP
5
ENABLE
+16
+9
+6
+3
0
-3
-6
-9
-12
-15
-20
-30
FOLLOW SML FADER
MUTE
SAFE/PREVIEW
PK!
10
+6
0
5
SIG
0
5
10
20
30
TB TO AUX6
MTX
1
+6
MTX
2
+6
MTX
3
+6
MTX
4
GRP
+6
5
POST PRE
=
PAN
L R
OUTPUT
0dB
0dB
0dB
0dB
POST PRE
-15
-20
-10
TRIM
-30
-5
0dB
GRP
6
ENABLE
+16
+9
+6
+3
0
-3
-6
-9
-12
-15
-20
-30
FOLLOW SML FADER
MUTE
SAFE/PREVIEW
PK!
10
+6
0
5
SIG
0
5
10
20
30
TB TO AUX7
MTX
1
+6
MTX
2
+6
MTX
3
+6
MTX
4
GRP
+6
6
POST PRE
=
PAN
L R
OUTPUT
0dB
0dB
0dB
0dB
POST PRE
-15
OUTPUT
-20
-10
TRIM
GRP
7
TRIM
-30
-5
0dB
GRP
8
ENABLE
+16
+9
+6
+3
0
-3
-6
-9
-12
-15
-20
-30
FOLLOW SML FADER
MUTE
SAFE/PREVIEW
PK!
10
+6
0
5
SIG
0
5
10
20
30
TB TO AUX8
MTX
1
MTX
2
MTX
3
MTX
4
GRP
7
PAN
L R
MTX
1
0dB
+6
MTX
2
0dB
+6
MTX
3
0dB
+6
MTX
4
0dB
GRP
+6
8
POST PRE
=
PAN
-10
-30
-5
PK!
+6
0
SIG
MTX
1
0dB
MTX
2
0dB
MTX
3
0dB
MTX
4
0dB
L TOMRTO M
-20
SAFE/PREVIEW
-15
10
20
30
0dB
+16
+9
+6
+3
0
-3
-6
-9
-12
-15
-20
-30
FOLLOW SML FADER
MUTE
10
5
0
5
TB TO AUX10
+6
+6
+6
+6
MONO
-10
LINE
REVERSE
10
MIC
-14
20
-10
-20
-30
-15 +15
-15 +15
-15 +15
-15 +15
ODD
+48V
POLARITYPOLARITY
MIC LINE
0dB
PAD
20
10
30
XLR
40
GAIN
50
6
40dB
60
50Hz
HPF
30
100
200
400HzOFF
POLARITY
(R)
STEREO
WIDTH
WIDE
0dB
-5
STEREO
GAIN
+5
+10dB
DIRECT
TO
L-R
STEREO
PFL
XLR STEREO
HF
12kHz
HM
2.5kHz
LM
250Hz
LF
70Hz
EQ IN
AUX
1
0dB
+6
AUX
2
0dB
+6
AUX
3
0dB
+6
AUX
4
0dB
+6
POST PRE
AUX
5
0dB
+6
AUX
6
0dB
+6
AUX
7
0dB
+6
AUX
8
0dB
+6
POST PRE
AUX
9
0dB
+6
AUX
10
0dB
+6
POST PRE
=
PAN
BAL
EVEN
L
R
-10
2TRK RETURN
-5
POST PRE
STEREO PFL
LEV
-5
-2 0dB
-10
+5
-20
+8
-30 +10dB
REPLAY TO L-R
PFL
AFL
ACTIVE
PFL
MONO
SNAPSHOT
+16
+9
+6
+3
MIDI
ACTIVE
CHANNEL
MODE
PATCH
SOLO IN-PLACE
SHIFT
EDIT SAFES
STORE
0
-3
-6
-9
-12
-15
-20
-30
48V
+V
-V
PREVIEW
TB MIC IN
TB TO M
TB TO L-R
TB TO GRP
TB TO MTX
5
4
6
TB
3
7
LEV
2
8
1
9
0
10
TALK
MTX
1
0dB
MTX
2
0dB
MTX
3
0dB
MTX
4
0dB
POST PRE
WEDGE MODE
+6
+6
+6
+6
POST PRE
M MIX AFL/PFL
MTX
1
0dB
MTX
2
0dB
MTX
3
0dB
MTX
4
0dB
MRL
2
2
-12
3
1
3
1
0dB
4
0
4
0
AUTO INCREMENT
DISABLE
5
5
EDIT GROUP
RECALL
+6
L-R MIX
6
10
6
10
PREVIEW
SCENE GROUPS
STEREO MONO
7
8
9
7
8
9
<>
PFL TRIM
LOCAL
LEV
PHONES
LEV
1
DISABLE
2
6 GL4800 User Guide
The Range
GL4800-24 24 channel console
GL4800-32 32 channel console
GL4800-40 40 channel console
GL4800-48 48 channel console
Stereo models can include mic/stereo line channels dependant on customer specification.
4 configurations are offered:
A – All mono channels (2 stereo returns are available above the masters)
B – 4 full stereo channels to right of masters
C – 4 full stereo channels to extreme right
D – 8 full stereos to right of masters
INPUT A INPUT BSYS-LINK V2
(option)
The Integral Meterpod provides illuminated moving coil VU metering of the groups, L, R, M (or monitors, LR sidefill, listen wedge). Also additional PFL/AFL indicator.
The console is supplied with a separate RPS11 power supply, DC power cable and mains cable with moulded plug.
The GL4800 features dual power connectors and built-in combiner circuitry to allow two RPS11s to be used for redundant supply backup.
GL4800-SLV2 Sys-Link V2 console expander
option kit (input only)
Circuit assembly and multi-pin connector system which can be fitted to the console to allow simple interconnection between two consoles so that one becomes the slave of the second by linking the audio busses and PFL/AFL system.
The GL4800 Sys-Link V2 option is an input-only version, which allows the console to act as a master console but not as a slave. Connections can be made using two standard 37way D-type cables to any other console fitted with a Sys-Link V2 output.
This option should be fitted only by your Allen & Heath agent or competent service personnel.
GL4800 User Guide 7
Introducing the Allen & Heath GL4800
The GL4800 offers the professional user an uncompromised feature set and performance for the latest techniques in live sound engineering and recording. The console is available in 24, 32, 40 and 48 channel sizes with an external 3U rack power unit. A built-in VU Meterpod is fitted as standard. An optional Sys­Link V2 input expander system is available.
• Dual function + live recording capability :
Large venue Front-of-House
Dedicated 14 mix (10 aux+4 matrix) stage monitor
Dual function combines Front-of-House and monitor
Live recording to 2-track and multitrack
• 24, 32, 40, 48 frame sizes including VU Meterpod
• Stereo models include mic/stereo line channels depending
on customer specification
• 8 groups with inserts and trimmable balanced XLR outputs
• L,R,M mix on balanced XLR and with inserts
• 10 Aux sends on balanced XLR and with inserts
• 4 Matrix capable of balanced XLR and inserts
• Matrix to aux link feature for group effects and quick monitors
• Secondary LR output capable of balanced XLR and inserts
• Channel Direct outputs with level trim and pre/post
• 4 band full sweep channel EQ with mid Q switches
• Stereo channel 4-point width control
• Separate insert jacks with balanced returns
• MIDI mute system with 128 snapshots
• 8 independent mute groups
• Solo-In-Place feature
• Full metering - channel, mix buss and outputs.
• Monitor with stereo PFL, local output, 2 phones ...
• Simultaneous stereo and mono PFL metering
• Output meter selector switches for main or aux
• Talkback to L-R, M, groups, matrix, and to each aux
• 2-track replay to L-R and monitor
The console is constructed using extruded aluminium beams, steel panels and 3mm thick metal side plates to ensure rigidity and mechanical reliability on the road, as well as easy flightcasing. Individual circuit assemblies are accessible by removal of the steel base. A durable but soft front armrest is provided for comfort. Front, top and rear write-on strips are provided for channel marking. High quality proven reliable parts are used throughout. High performance op­amp and discrete circuits are used to ensure low noise and sonic purity.
The GL4800 reflects our commitment to providing the best audio mixing solutions and customer support.
8 GL4800 User Guide
Here are just a few key points we considered when specifying the GL4800:
Affordability We understand your need to work within a realistic budget and know you
want to get the very best return for your investment. We know too that even the lowest budget shows put the same tough demands on the operator who wants the reassurance of continued reliability and intuitive control, the satisfaction of achieving that special sound, and the functionality to deal with the trickiest situations. We have avoided the temptation of designing in costly plastic trims and needless external add-ons for styling only. Instead we have invested every penny of our budget into parts that make a real difference in improving performance, durability and flexibility of use, whether the comfortable soft feel armrest, the practically shaped space saving steel chassis, the exceptional feature set, or the ‘under the bonnet’ engineering such as the solid grounding, individual cards, circuit enhancements and more. The result is a no-nonsense, durable mixing tool right for its application… a sensible investment.
Reliability Without doubt, the most important quality for any equipment intended for the
professional application. The GL4800 uses the well proven and long term serviceable Allen & Heath method of individual channel card construction with every potentiometer nutted to the front panel, a solid steel chassis with rigid beam front extrusion, 100mm premium grade dual rail faders, metal bodied jacks and gold-plated Neutrik XLRs, and sealed Alps pots and switches to ensure you can mix with confidence show after show. The well proven RPS11 power supply has plenty of overhead and, for peace of mind, the console includes a second DC input socket for plugging in a second supply for backup.
Performance The GL4800 benefits from our latest circuit developments which have
improved the sound and responsiveness of the signal path and EQ, and achieved astonishingly low residual noise from the mix head amp and output stages, crucial when mixing into modern high powered speaker systems. The mic preamp maintains ultra low distortion and can accept as much as+34dBu to deal with the hottest signal you are ever likely to plug in. The XLR outputs provide proper differential drive up to a massive +27dBu to work with the longest and most hostile cable environments. Extensive listening evaluation, together with solid engineering practice, have ensured the console achieves accurate sound reproduction under all conditions.
Capability We know a thing or two about ‘Dual Functionality’ having pioneered this
innovative feature back in the early 90’s. The GL4800 takes this an important stage further. Tamperproof recessed switches configure the console safely for optimum FOH or stage monitor operation, or for mixing monitors from FOH. In MONITOR mode the ‘M’ fader becomes the engineer’s monitor wedge control, you get all 10 aux masters available on faders with mutes, inserts, meters and electronically balanced XLR drive, and you still get the 4 subgroups to LR, and the groups/LR feeding the matrix. The matrix provides further mixes ideal for in-ear monitoring, or can even be linked to the auxes to create mixes from all channels, groups, LR and M. This console can feed up to 14 independent mixes, for example 10 wedges and 4 mono or 2 stereo IEM. We have also considered the RECORDING application with direct outputs on all mono channels, 4 groups, matrix and not least the studio quality analogue mic preamps and EQ. Whatever your application you get full control with nothing wasted.
Attention to detail In true Allen & Heath form, every detail has been meticulously
thought through. Take for example, the compact, no frills chassis that gives you a seat saving, flight case convenient footprint, the provision of individual channel rather than restrictive global pre/post aux switching, comprehensive talkback, full channel, mix bus and main output metering, the multi-functional stereo strips with patchable mic pre’s and assignable stereo inputs, the host of internal jumper options, Sys-Link V2 console input expansion… and much more. We hope you enjoy being as creative using the GL4800 as our team enjoyed creating it.
Carey Davies, Head of Design, and sound guy too…
GL4800 User Guide 9
Dimensions and Weights
Dimensions shown in millimetres
UNPACKED Width Depth Height Wt(kg)
GL4800-824 1166 (46”) 748 (29”) 285 (11”) 47(104lbs)
285
132.5 (3U)
GL4800-832 1421(56”) 748 (29”) 285 (11”) 57(126lbs)
GL4800-840 1676(66”) 748 (29”) 285 (11”) 67(148lbs)
GL4800-848 1931(76”) 748 (29”) 285 (11”) 77(170lbs)
232
RPS11 483(19”) 232 (9”) 135 (3U) 10(22lbs)
PACKED Width Depth Height Wt(kg)
GL4800-824 1702 (67”) 900 (35”) 390 (15”) 82 (181lbs)
GL4800-832 1702 (67”) 900 (35”) 390 (15”) 91 (201lbs)
GL4800-840 1950 (77”) 900 (35”) 390 (15”) 100 (221lbs)
0
5
GL4800-848 1950 (77”) 900 (35”) 390 (15”) 129 (284lbs)
RPS11 575 (23”) 270 (11”) 170 (7”) 11 (24lbs)
7
7
GL4800-824 = 1166
GL4800-832 = 1421
GL4800-840 = 1676
GL4800-848 = 1931
75
35
78
x 8 x 8 x 8 x 8 x 8 x 8
10 GL4800 User Guide
Specifications
Performance
0dBu = 0.775 Vrms Reference for high level equipment +4dBu = 1.23 V
0dBV = 1 Vrms Reference for low level equipment -10dBV = 310 Mv
0VU meter reading = +4dBu at XLR outputs
Input Gain
Mic/Line Input +6dB to +60dB variable
Mic/Line + Pad -14dB to +40dB variable
Line Input -14dB to +40dB variable
Stereo Line Input off to +10dB variable
2-track Return off to +10dB variable
Maximum Output Level
Main Outputs +27dBu into load of >600 ohm
Jack Outputs +21dBu into load of >2K ohm
Internal headroom +21dB
Frequency Response
Measured 20Hz to 20kHz ref 1kHz
Mic to mix (+40dB) +0/-0.5dB
Line to mix (0dB) +0/-0.5dB
Distortion
THD + noise measured @ 1kHz +20dBu
Mic to mix (+40dB) 0.006%
Line to mix (0dB) 0.006%
Crosstalk
Referred to driven channel @ 1kHz
Channel to channel > 100dB
Mute shutoff > 85dB
Fader shutoff > 90dB
Noise Performance
Measured rms 22Hz to 22kHz bandwidth
Mic EIN -128dB 150 ohm source
Line pre-amp (0dB) < -91dBu
Residual output noise < -98dBu (-102dB S/N)
Mix noise, nothing routed < -88dBu (-92dB S/N)
Mix noise, 24 channels routed < -86dBu (-90dB S/N)
Metering
Input meters 4 segment LED (signal, 0, +6, peak)
Mix meters 4 segment LED (signal, 0, +6, peak)
Output meters 12 segment LED
LED meter response peak reading
Peak indicators on 5dB before clipping
Signal indicators on -20dBu
Meterpod Illuminated VU moving coil meters
GL4800 User Guide 11
Mode Switching
Protected underpanel mode switches set the console architecture according to the required application, for example FOH or stage monitor. Select these using a pointed object.
GL4800
SYSTEM BLOCK DIAGRAM
PEAK
POST
PRE
EQ IN
+6 0dB SIG
FADER
POST-EQ
PRE-EQ
PRE-FADE SWITCHED POST-FADE
PFL
MONO
L-R
PAN
POST-MUTE PRE-MUTE
POST PRE
POST PRE
AUX 1
AUX 2
AUX 3
AUX 4
AUX 5
AUX 6
AUX 7
AUX 8
1-2
3-4
5-6
7-8
-
MUTE
SAFE/PREVIEW
-
DIR OUT routes the channel direct out signal through the aux 10 pre/post selector and level control.
OUT REV
OUT REV swaps the matrix or LR2 output jack with the related aux XLR and insert. The control sections are not swapped. This can provide matrix outputs on XLR with inserts, or aux effects sends on jack as required.
-15
0dB
-10
-5
OUTPUT
TRIM
GRP
8
-20
-30
ENABLE
Output Trim ENABLE routes the group
MIC/ LINE
LINE IN
-20dBu
BAL
MIC/LINE IN
2= +
+48V
SEND
INSERT
0dBu
RETURN
TIP = +
RING = -
BAL
INPUT CHANNEL
DIRECT OUT
0dBu
IMPEDANCE BALANCED
TIP = +
RING = -
GAIN
+
-
LO-CUT FILTER
AUX 10/
DIR OUT LEVEL
-
4-BAND FULL SWEEP
EQUALISER
HF
MF1
MF2
LF
INTERNAL AUX LINK OPTIONS
PRE FADER
POST FADER
AUX 10
AUX 9
output signal through a pre/post fader selector and level trim. This lets you record the groups independent of the subgrouping to LR and M.
MTX
1
TO AUX1
MTX TO AUX Links the matrix mix into the aux mix to include aux sends from the groups, LR and M. Used for effects from the groups, and for quick monitor mixes.
GRP REV
GRP REV reverses the aux (small fader) and group (main fader) control sections. Also applies to LR. The outputs remain unaffected. This mode is used for stage monitoring.
WEDGE MODE
M MIX AFL/PFL
STEREO CHANNEL
MIC IN
GAIN
PAD
-20dBu
MIC IN
2= +
+48V
SEND
INSERT
0dBu
RETURN
TIP = +
RING = -
MIC
STEREO
STEREO LINE IN
L/MONO
STEREO LINE IN
TIP = +
RING = -
R
BAL
R
LO-CUT FILTER
+
-
+
-
L
R
WIDTH
4-BAND
EQUALISER
HF
MF1
MF2
LF
INTERNAL AUX LINK OPTIONS
GAIN
L
R
POST
PRE
AUX 10
AUX 9
EQ IN
STEREO PFL
DIR TO L-R
PEAK +6 0dB SIG
STEREO PFL
FADER
POST-EQ
PRE-EQ
PRE-FADE SWITCHED POST-FADE
-
MUTE
SAFE/PREVIEW
-
POST-MUTE PRE-MUTE
POST PRE
POST PRE
PAN
AUX 1
AUX 2
AUX 3
AUX 4
AUX 5
AUX 6
AUX 7
AUX 8
MONO
L-R
1-2
3-4
5-6
SUM
7-8
SUM
LEFT
RIGHT
MONO
PFL
AFL
AUX 1-10
GRP 1-8
MTX A-D
LEFT
RIGHT
MONO
PFL
AFL
AUX 1-10
GRP 1-8
MTX A-D
MONO MODE converts the mono output to the monitor engineers listen wedge. M AFL is disabled. The M mix still feeds the insert and matrix.
TALKBACK
TB MIC IN
BAL
2= +
TB LEV
TALK
LINK
+48V
TB ENABLED
DIM
ENABLE
TB TO MONO
TB TO L-R
TB TO GRPS
TB TO MTX
12 GL4800 User Guide
System Diagram
LEFT
RIGHT
MONO
PFL
AFL
AUX 1-10
GRP 1-8
MTX A-D
LEFT
RIGHT
MONO
PFL
AFL
AUX 1-10
GRP 1-8
MTX A-D
2-TRACK
RETURN
LEV
L
IN
R
STEREO PFL
REPLAY TO L-R
-
-
OUTPUT REVERS E (LR2 / AUX 9-10)
-
AUX
AFL
S
=SYSLINK INPUT OPTION
LEV
-
L(R)2
ON
AUX
L(R)2 OUT
-
IMPEDANCE BALANCED
0dBu
OUTPUT REVERSE (M TX 1-4 / AUX 5-8)
TB TO AUX
ENABLE
S
INSERT
S
INSERT
SEND
RETURN
SEND
RETURN
0dBu
BAL
GRP MIX
0dBu
BAL
MTX MIX
MTX TO AUX (1-4)
-
AUX MIX
+
-
+
-
LEV
AFL
MATRIX (1-4)
GROUP/AUX REVERSE
PEAK +6
AUX (1-10)
0dB SIG
SML FADER
AFL
PEAK +6
GROUP (1-8)
0dB SIG
MAIN FADER
AFL
POST-MUTE PRE-MUTE
-
-
MUTE
SAFE/PREVIEW
-
MUTE
SAFE/PREVIEW
-
POST
POST
ON
SML
METER
MAIN
TRIM
POST
VU
+
PRE
MTX 1
TRIM ON
MTX (1-4) OUT
-
IMPEDANCE BALANCED
-
-
0dBu
AUX (1-10) OUT
2 = +
GRP (1-8) OUT
2 = +
+4dBu
BAL
MTX 2
MTX 3
POST
MTX 4
PRE
MONO
PRE
PAN
L-R
MATRIX SENDS
SUBGROUPING
AUX AUX AUX
POST
RL METER
MONITOR
-
-
AFL
L(R) / AUX9(10) REVERSE
AFL
POST-MUTE PRE-MUTE
PEAK +6
L(R)
0dB SIG
MAIN FADER
-
MUTE
SAFE/PREVIEW
-
LOCAL
MONO
L
R
M
SUM
PHONES
LRM
PEAK
MONO
+6 0dB SIG
FADER
-
MUTE
SAFE/PREVIEW
-
SML
MAIN
POST
PRE
+
+
+
+
AFL ACTIVE
PFL ACTIVE
MONO / LISTEN WEDGE
POST
PRE
VU
POST
PRE
MTX 1
MTX 2
MTX 3
POST
MTX 4
PRE
MONO
L
L
LOCAL MONITOR OUT
R
PHONES 1
PHONES 2
VU
MONO MODE
MTX 1
POST
PRE
MTX 2
MTX 3
MTX 4
L(R) MIX
S
SEND
INSERT
RETURN
0dBu
BAL
+
-
R
AFL MIX
S
PFL MIX
L
R
PFL
DC
AFL
PFL TRIM
L-R MIX
PFL DC
P/AFL DC
STEREO PFL METER
S
INSERT
MONO MIX
RETURN
SEND
0dBu
BAL
+
-
TB DIM
PRE-MUTE
L(R) OUT
2 = +
MONO OUT
MATRIX SENDS
MATRIX SENDS
+4dBu
BAL
+4dBu
BAL
-
2 = +
-
GL4800 User Guide 13
STEREO CHANNELS
STEREO
LINE
IN
R
SEND
XLR INSERT
RET
LINE
MIC
IN
Connectors
L
/MONOL
/MONO
STEREO
LINE
IN
R
SEND
XLR INSERT
RET
LINE
MIC
IN
GL4800
Professional gold plated connector types are used to ensure continued reliable operation. All the console main inputs and outputs are balanced XLRs. All 1/4" jacks are 3-pole TRS for operation with balanced or unbalanced equipment. Inserts are provided on all channel inputs, and on Groups, L, R, Mono and all Aux outputs. Aux can be swapped with matrix and LR2 for XLR outputs with inserts
LOCAL
L
SEND
SEND
SEND
SEND
SEND
SEND
SEND
RESET
IN
MIDI
THRU
OUT
CHASSIS GROUND
DC POWER IN
A
(BACKUP)
(MAIN)
SEND
INSERT
INSERT
INSERT
INSERT
INSERT
INSERT
INSERT
INSERT
4321
MTX
RET
RET
RET
RET
RET
SEND
SEND
SEND
SEND
INSERT
INSERT
INSERT
INSERT
RET
RET
RET
RET
B
M
LISTEN WEDGE
AUX8
LR
2-TRACK RETURN
L
R
R
METERPOD
765
MATRIX
22 LR
9AUX10
FOR MATRIX/LR2 ON XLR + INSERTS =
SEND
SEND
SEND
SEND
INSERT
INSERT
INSERT
INSERT
RET
RET
RET
RET
AUX
10
MONITOR 10 MONITOR 9 MONITOR 8 MONITOR 7 MONITOR 6 MONITOR 5 MONITOR 4 MONITOR 3 MONITOR 2 MONITOR 1 STAGE MONITOR MODE
OUT REV
SEND
SEND
SEND
SEND
INSERT
INSERT
INSERT
INSERT
RET
RET
RET
RET
AUX
9
GL4800
SEND
SEND
INSERT
INSERT
RET
RET
GRP
GRP
OUT2
MODE
SEND
SEND
SEND
SEND
SEND
SEND
SEND
SEND
INSERT
INSERT
INSERT
INSERT
INSERT
INSERT
INSERT
INSERT
RET
RET
RET
RET
RET
RET
RET
RET
AUX
AUX
L2R2 MTX1MTX2MTX4 MTX3
7
SERIAL NUMBER
SEND
SEND
INSERT
INSERT
RET
RET
GRP
GRP
SEND
SEND
SEND
SEND
SEND
SEND
SEND
SEND
INSERT
INSERT
INSERT
INSERT
INSERT
INSERT
INSERT
INSERT
RET
RET
RET
RET
RET
RET
RET
RET
AUX
AUX
5
6
MADE IN ENGLAND BY ALLEN & HEATH LIMITED
SEND
SEND
INSERT
INSERT
RET
RET
GRP
GRP
SEND
SEND
INSERT
INSERT
RET
RET
RETRETRET
AUX
AUX
SEND
SEND
INSERT
INSERT
RET
GRP
SEND
INSERT
RET
AUX
RET
GRP
12456783
SEND
INSERT
DIRECT
DIRECT
OUT
GRP
INSERT
RET
AUX
1243
AUX
LINE
MIC
OUT
SEND
SEND
INSERT
RET
RET
LINE
LINE
IN
LINE
MIC
IN
IN
IN
DIRECT
OUT
SEND
INSERT
LINE
LINE
MIC
IN
LINE
IN
SEND
XLR
INSERT
RET
IN
RET
L
R
/MONO
Direct Output
Provides a buffered signal from the channel, ideal for minimum signal path connection to multitrack recorders or local effects sends. Set post-fader, post-mute as standard. Can be switched through the Aux10 send control for pre/post fader selection and level trim with +6dB maximum boost.
3-pole 1/4" jack socket (tip = hot). Impedance balanced 50 ohm 0dBu line level for connection to balanced or unbalanced equipment.
Insert Send
Used to send the channel signal to external effects and signal processing equipment, post-pre-amp and pre-EQ.
3-pole 1/4" jack socket (tip = hot).
Impedance balanced 0dBu 50ohm line level.
Insert Return
Used to return the processed signal from external equipment into the channel audio signal path pre-EQ.
3-pole 1/4" jack socket (tip = hot). Balanced >10kohm 0dBu line level. (Stereo channel returns are unbalanced).
Mic/Line Input
3-pin female XLR (pin 2 = hot). Electronically balanced.
74dB gain range. Mic impedance >2kohm, line >10kohm
Can be used for XLR line input when the LINE IN jack is left unplugged.
Mono Channel Line Input
LINE
MIC
IN
3-pole 1/4" jack socket (tip = hot). Electronically balanced >10kohm.
Stereo Channel Line Input
3-pole 1/4" jack socket (tip = hot). Electronically balanced >10kohm. Plug into the Left input only for a mono line source.
14 GL4800 User Guide
SEND
INSERT
RET
GRP
Sys-Link V2 Expander Option
Available as a kit to be fitted to the console to expand the busses. Uses 2 37-pin D-type connectors (input A and B). Operates at -2dBu line level. Input option available only. Refer to your Allen & Heath agent for further details.
Group/Aux/L/R/M Insert Send
Used to send the output signal to external effects and signal processing equipment such as graphic equalisers, delays and compressors, post-mix amp and pre-fader.
3-pole 1/4" jack socket (tip = hot).
1
GRP
Impedance balanced -2dBu 50ohm line level.
Group/Aux/L/R/M Insert Return
INSERT
INSERT
INSERT
INSERT
SEND
SEND
SEND
SEND
RET
INSERT
SEND
RET
AUX
1
MONITOR 1
SEND
SEND
SEND
SEND
INSERT
INSERT
INSERT
INSERT
RET
RET
RET
RET
AUX
LR
Used to return the processed signal from external equipment into the output audio signal path pre-fader and mix meter.
3-pole 1/4" jack socket (tip = hot). Balanced >10kohm -2dBu line level.
Group/Aux/L/R/M Main Output
3-pin male XLR (pin 2 = hot). Electronically balanced 75ohm. +4dBu line level, +27dBu maximum into 600 ohm load.
Capable of driving long cable runs without loss or interference.
Mode Switching
Set the underpanel mode switches for the intended console operation. Some of these affect the way the connectors work. For full details please refer to the BLOCK DIAGRAM.
OUT REV underpanel mode switch - The Aux XLRs and inserts can swap
SEND
SEND
SEND
SEND
INSERT
INSERT
INSERT
INSERT
RET
RET
RET
RET
M
LISTEN WEDGE
GL4800 User Guide 15
with the Matrix and LR2 output jacks for aux (effects) sends on jacks if required. This also provides matrix and LR2 outputs on XLRs with inserts for driving speaker systems.
MONO MODE underpanel mode switch - The Mono output becomes the
engineers listen wedge monitor feed when the console is operated in on-stage monitor mode. However, the Mono insert remains with the mono mix.
MIX/AUX REV underpanel mode switch - Note that while the front panel
control sections are swapped when the reverse mode switches are pressed, the signals always appear at their related connectors, ie. the connectors do not swap.
LOCAL
R
L
Meterpod Connector
METERPOD
4321
MTX
AUX8
765
22 LR
9AUX10
FOR MATRIX/LR2 ON XLR + INSERTS =
SEND
SEND
SEND
INSERT
INSERT
INSERT
INSERT
SEND
RET
RET
RET
RET
AUX
9
SEND
SEND
SEND
SEND
INSERT
INSERT
INSERT
INSERT
RET
RET
RET
RET
AUX
10
MONITOR 10 MONITOR 9
MATRIX
OUT2
MODE
OUT REV
L2R2
Recessed 16-pin dual row header for connection to the meterpod.
Local Stereo Monitor
For connection to a stereo amplifier/speaker system for LR, AFL/PFL monitoring local to the console.
3-pole 1/4" jack sockets (tip = hot). Impedance matched 50ohm 0dBu nominal line level.
Headphones
Connections for 2 stereo headphones >8ohms. One connector is on the front panel, the other is concealed under the armrest.
3-pole 1/4" jack sockets (tip = left, ring = right).
Matrix Output
3-pole 1/4" jack socket (tip = hot). Impedance balanced 50ohm 0dBu nominal line level.
Can swap with the aux output XLRs and inserts to drive long cable runs without loss or interference, and to insert external signal processing devices such as graphic equalisers and delays.
LR2 Output
MIDI
RESET
THRU
OUT
Secondary LR output for 2-track recording, broadcast or additional speaker and zone feeds.
3-pole 1/4" jack socket (tip = hot). Impedance balanced 50ohm 0dBu nominal line level.
2-TRACK
RETURN
L
Can swap with the aux output XLRs and inserts to drive long cable runs without loss or interference, and to insert external signal processing devices such as graphic equalisers and delays.
R
2-Track Return Input
For connection to 2-track playback equipment such as cassette, DAT or CD players.
IN
3-pole 1/4" jack sockets (tip = signal). Unbalanced 50ohm. +10dB maximum gain allows connection to low and high level equipment.
MIDI Interface
Standard 5-pin 180' connectors for opto-isolated connection to other MIDI equipment. A mute processor reset switch is provided.
A
CHASSIS GROUND
DC POWER IN
INSERTINSERTINSERTINSERT
B
Console DC Power Input
The console connects to a separate power supply unit via a 10-pin circular connector cable. Connect only the Allen & Heath power unit supplied with the console. The standard power supply is the RPS11. Plug in a second RPS11 if a redundant backup is required.
(MAIN)
(BACKUP)
A chassis ground terminal post is provided. This connects to mains earth through the power cable.
16 GL4800 User Guide
Earthing
The connection to earth (ground) in an audio system is important for two reasons:
1. SAFETY - To protect the operator from high voltage shock associated with the AC mains supply feeding the system, and
2. AUDIO PERFORMANCE QUALITY - To minimise the effect of earth (ground) loops which result in audible hum and buzz, and to shield the audio signals from external interference.
For safety it is important that all equipment earths are connected to mains earth so that exposed metal parts are prevented from carrying high voltage which can injure or even kill the operator. A solid, low impedance earth system is necessary to ensure that earths at different points in the system are kept at the same potential. A typical sound system includes amplifiers, signal processing equipment, microphones, musical instruments and much more in addition to the console, all of which require earth connection for safety and correct audio operation. Often this equipment is spread across the venue and interconnected by hundreds of metres of power and audio cables. It is recommended that the sound engineer check the continuity of the safety earth from all points in the system including microphone bodies, guitar strings, muticore cases, equipment panels ...
The same earth is also used to shield audio cables from external interference such as the hum fields associated with power transformers, lighting dimmer buzz, and computer radiation. Earth is also used for the signal 'return' when connecting to unbalanced equipment. Problems arise when the signal sees more than one path to mains earth. An 'earth loop' (ground loop) results causing current to flow between the different earth paths. A larger potential difference between these paths results in more current flow and so more audible noise. This condition is usually detected as a low frequency hum or buzz at mains frequency or its harmonics.
To ensure operator safety and trouble-free audio performance from your system we recommend the following :
Do not remove the earth connection from the power unit mains plug. The console chassis is connected to mains earth through the power cable to ensure your safety. Audio 0V is connected to the console chassis internally. If problems are encountered with earth loops operate the audio 'ground lift' switches on connected equipment accordingly, or disconnect the cable screens at one end, usually at the destination. It is useful to carry ground lift cable adaptors such as short XLR male to female leads with pin1 disconnected.
Use a separate 'clean' mains outlet for the audio equipment to prevent interference from other equipment such as lighting, stage machinery and vending machines. Ensure a good central 'star point' earth connection.
Avoid running audio cables next to mains, computer or lighting cables, or near thyristor dimmer and power supply units. If unavoidable, cross these at right angles.
Use low impedance sources such as 200 ohm or less microphones to reduce susceptability to interference. The console outputs are designed to operate at very low impedance to minimise interference problems.
Use balanced connections where possible as these provide further immunity by cancelling out interference that may be picked up on long cable runs. To connect an unbalanced source to a balanced console input, link the cold input (XLR pin3 or jack ring) to 0V earth (XLR pin1 or jack sleeve) at the console. To connect a balanced console output to an unbalanced destination, link the cold output to 0V earth at the console.
Use professional quality cables and connectors and check for correct wiring and reliable solder joints.
If you are not sure ... Have your system checked by a competent engineer, or contact your local Allen & Heath agent for advice.
GL4800 User Guide 17
Connecting Power
Connect only the Allen & Heath power unit specified for the console. The standard unit for GL4800 is the RPS11. This is an external 3U 19" rack mounted unit that connects to the console via the separate DC cable supplied. The RPS11 is a low noise linear design that converts AC mains voltage to the DC voltages required to power the console. It also provides +48V phantom power for use with high quality powered microphones. The presence of AC mains voltage is shown on the power unit front panel neon indicator. The presence of the DC voltages is shown on the console power indicator LEDs. A second backup RPS11 may be connected to the console via the backup DC power connector (located adjacent to the main DC power connector at the rear of the console).
DO NOT OBSTRUCT VENTILATION OPENINGS. ALLOW ADEQUATE VENTILATION AROUND THE UNIT. SEE INSTALLATION INSTRUCTIONS BEFORE CONNECTING TO THE SUPPLY.
POWER
ON
DC FUSES
CAUTION: FOR CO NTINUED PROTEC TION AGAINST R ISK OF FIRE
REPLACE FUSE WITH SAME TYPE AND RATING.
ATTENTION: REMPLACER LE FUSIBLE AVEC UN DES MEMES
CARACTERISTIQUES.
T 10A 250V 20mm
V+
V-
OFF
DO NOT OBSTRUCT VENTILATION OPENINGS. ALLOW ADEQUATE VENTILATION AROUND THE UNIT.
WARNING: THIS APPARATUS MUST BE EARTHED.
WARNING: TO REDUCE THE RISK OF ELECTRIC SHO CK, DO NOT EXPOSE THIS APPARATUS TO RAIN OR MOISTURE
CAUTION
AVIS: RISQUE DE CHO C ELECTRIQUE - NE PAS OUVRIR.
NO USER SER VICEABLE PARTS INSIDE
CAUTION: FOR CONT INUED PROTECTION AGAINST RISK OF FIRE REPLACE FUSE
WITH SAME TYPE AND RATING.
ATTENTION: REMPLACER LE FUSIBLE AVEC UN DES MEMES CARACTERISTIQUES.
WARNING: THIS APPARATUS MUST BE EARTHED. WARNING: TO REDUCE THE RISK OF EL ECTRIC SH OCK, DO NOT EXPOSE THIS APPARATUS TO RAIN OR MOISTURE
CONSOLE POWER SUPPL Y
SERIAL No:
AVIS: RISQUE DE CHOC E LECTRI QUE - NE PAS OUVRIR.
NO USER SERVICEABLE PARTS INSIDE
CAUTION: FOR CONTINUED PROTECTION AGAINST RISK OF FIRE REPLACE FUSE
WITH SAME TYPE AND RATING.
ATTENTION: REMPL ACER LE FUSIBLE A VEC UN DES MEMES CARACTERISTIQUES.
AC MAINS IN ~
FUSE TYPE AC SUPPLY
T 3.15A 20mm 220 - 240V~ T 5.0A 20mm 100 - 120V~
47-63Hz 320VA MAX 300W MAX
Made in the UK by
RPS11
DC OUT
SAFETY WARNINGS !
Ensure that the warnings printed on the
power unit (shown here) are followed.
Always switch the power unit off before connecting or disconnecting the console power cable.
It is normal for the power unit to dissipate heat. Do not cover the unit or position it on soft furnishings during operation. Do not position other equipment known to generate significant amounts of heat below the unit. It is recommended that rack units containing high power amplifiers and other heat dissipating equipment are fitted with cooling fans.
Before Switching On !
Check that the voltage indicated on the
AC MAINS IN ~
fuseholder is correct for the mains voltage in your area.
Check that the mains IEC connector is fully inserted into the inlet socket.
FUSE TYPE AC SUPPLY
T 3.15A 20mm 220 - 240V~ T 5.0A 20mm 100 - 120V~
47-63Hz 320VA MAX 300W MAX
Check that the DC power cable is correctly fitted to both the power unit and the console. The locking ring should be screwed in place.
A
(MAIN)
DC POWER IN
B
Console DC Power Connectors
(BACKUP)
It is recommended that audio power amplifiers are switched on last and switched off first to prevent possible damage to loudspeakers.
Check the system for safety earthing.
18 GL4800 User Guide
Matching the Signal Levels
For best performance it is important that the connected source signals are matched to the "normal operating level" of the console. Similarly the console outputs should be correctly matched to the operating levels of the connected amplifiers and destination equipment. If too high the signal peaks will be clipped resulting in a harsh distorted sound, and if too low the signal-to-noise ratio is reduced resulting in excessive background hiss and noise.
For best results operate the console with the meters averaging around '0' letting the louder passages peak into the 'yellow'. Reduce the gain if the red peak indicators flash. The GL4800 produces a standard XLR output level of +4dBu for a meter reading of 0VU. It is advisable to adjust the power amplifier input gain or fit an attenuator pad if normal console operation results in an output level too high for the connected amplifier. Normal operation should result in fader levels around the '0' mark. Note that when reversed with the auxes the matrix and LR2 output level trims can be used to match the console to the amplifiers independent of the mix levels. Similarly the group output trims can be switched in to match levels.
The GL4800 has an advanced PFL (pre-fade listen) / AFL (after-fader listen) and channel metering system to let you listen to and check the level of signals at different points in the signal path without affecting the main outputs. Use the channel PFL switches to set up the input GAIN controls to read an average '0'. Signal activity is always shown on the channel meters regardless of fader position. The green 'SIG' LED lights at -20dBu to indicate signal presence, the green '0' LED indicates normal level, yellow '+6' indicates normal peaks, and the red 'PEAK' LED warns of potential overload 5dB before clipping.
The mix meters above each output fader monitors the pre-fade mix level. You can run the mix 'hot' but reduce the channel fader levels if the red 'PEAK' LEDs flash.
Dynamic Range
GL4800 User Guide 19
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