Allen&Heath GL2800 User Manual

ALLEN&HEATH

GL2800

USER GUIDE

Publication AP6095

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 complies with the European Electromagnetic Compatibility directives 89/336/EEC & 92/31/EEC and the European Low Voltage Directives 73/23/EEC & 93/68/EEC.

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.

GL2800 User Guide AP6095 Issue 3

ALLEN&HEATH Limited

Kernick Industrial Estate, Penryn, Cornwall, TR10 9LU, UK http://www.allen-heath.com

2 GL2800 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 and power units with

their covers 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: To reduce the risk of fire or electric shock

do not expose the console or its power units to rain or moisture or use in damp or wet conditions. Do not place containers of liquids on surfaces where liquid may spill into any openings.

Ventilation: Do not obstruct the power supply heatsinks and

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.

GL2800 User Guide 3

General Precautions



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 or its power unit 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



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.

Ensure that these colour codes are followed carefully in the event of the plug being changed.

WIRE COLOUR

4 GL2800 User Guide

Introduction

Welcome to the Allen & Heath GL2800, the latest generation of the popular GL series of dual function live sound 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 and technical specification. 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, resource downloads, our company pedigree, contact details, assistance with your technical queries, or simply to chat about 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.

http://www.allen-heath.com

http://www.glseries.com

Contents

Gain Structure.................................................. 25

Using the Oscillator / Noise Generator ........... 26

Mixing with Faders or Gain Controls............... 26

Using PFL / AFL ............................................... 27

The dB.............................................................. 27

Using Inserts ....................................................27

Polarity ............................................................. 28

Mixing the PA in Mono or Stereo? .................. 28

Zero the console .............................................. 28

Turning the System On or Off ......................... 28

Sound Levels ...................................................28

Dual Functionality ............................................29

Applications for the Matrix............................... 30

Create IEM Mixes with Ambience ................... 31

Using the Matrix to Create a Recording.......... 31

Recording with the GL2800............................. 31

Pre/Post Fade Aux Settings ............................ 31

Mix and Aux-Fed Subs .................................... 32

Other M Output Applications........................... 32

Using the Channel Direct Outputs .................. 32

Using the Stereo Channels ............................. 33

A Note about Combining Signals ................... 33

Warranty................................................. 2

Important Safety Instructions ................3

General Precautions ..............................4

Introduction to this Guide...................... 5

Panel Layouts ........................................ 6

Introducing the GL2800....................8

Installing the Console ..........................10

Connecting Power ...............................11

Audio Connections ..............................13

The Console Connectors ....................14

Mono Input Channel ............................16

Stereo Input Channel........................... 18

Stereo Return Channel ........................19

Group/Aux Masters.............................. 20

Mute, Aux 9-10 and L-R-M Masters..... 21

12x4 Matrix........................................... 22

2-Track Replay and Console Monitor .23

Talkback and Signal Generator ..........24

Applications and Operating Tips.........25

Specifications ......................................34

System Block Diagram ........................36

User Options........................................37

Cue Sheets ..........................................40

GL2800 User Guide 5

GAIN

HF

12k

HM

LM

LF

80Hz

AUX

1

AUX

2

AUX

3

AUX

4

AUX

5

AUX

6

AUX

7

AUX

8

AUX

9-10

STEREO

PAN

PK! +6

0

SIG

L-R

1-2

3-4

5-6

7-8

M1

M2

M3

M4

0

1k

700

500Hz

-15

70

45

35Hz

-15

ODD

M

30

20

-15 3k

180

OO +6

=

L R

=

L

+48V

POLARITY

LINE

(PAD)

40

60 40-14 6

HPF

100Hz

+15

15k

+15

1k

+15

EQ IN

PRE-EQ

POST PRE

+6OO

POST PRE

EVEN

PFL

10

5

0

5

10

20

30

00

GL2800GL2800

GAIN

HM

LM

250Hz

80Hz

9-10

STEREO

BAL

PK! +6

0 SIG

L-R

1-2

3-4

5-6

7-8

-20

-30

HF

12k

2k5

LF

AUX

1

AUX

2

AUX

3

AUX

4

AUX

5

AUX

6

AUX

7

AUX

8

AUX

M

M1

M2

M3

M4

0

30

20

-10

O

OO +6

L

ODD

+48V

POLARITY

LINE

(PAD)

HPF

-5

EQ IN

=

10

5

0

5

10

20

30

00

100Hz

+15-15

MUTE

PFL

STEREO

PK! +6

0

SIG

2TRK REPLAY

OO

POWER

L

PFL/AFL

MONITOR

PHONES

+10

2TRK TO LR

R

+16 +9 +6 +3

0

-3

-6

-9

-12

-16

-20

-30

100

M

L-R

2TRK

MTX1

MTX2

MTX3

MTX4

AUX 9-10

WEDGE MODE

DUAL STEREO RETURNDUAL STEREO RETURN

STEREO

0

40

50

60 40-14 6

0

5

16

GAIN

STEREO

GAIN

9-10

-5 5

-10

-20

16

OO

DIRECT TO

0

-5 5

-10

-20

OO

16

AUX

1

+6OO

AUX

2

+6

OO

AUX

+6OO

MUTE

PFL

10

M

5

+6OO

+6OO+6OO

+6OO

POST PRE

+6OO

L-R

0

1-2

5

10

20

30

OO

AUX

1

OO

AFL

PAN

L

PK! +6

0

SIG

REV

GRP1 TO M

TO LR=TO LR

R

+6OO

POST PRE

+6OO

RL

POST PRE

R

EVEN

STEREO

0

-5

GAIN

ST1

10

LR

ST2

10

STEREO

GAIN

9-10

5

-10

10

-20

16

OO

DIRECT TO

0

-5 5

-10

10

-20

OO

16

AUX

1

+6OO

AUX

2

+6

OO

AUX

+6OO

MUTE

PFL

10

M

5

L-R

0

3-4

5

10

20

30

OO

AUX

0 0

2

OO+10

+10

3

OO +10 OO

0

AFL AFL AFL AFL AFL AFL AFL

REV REV REV REV REV REV REV REV

GRP2 GRP4GRP3 GRP5 GRP6 GRP7 GRP8 TO MTO MTO MTO MTO MTO MTO M

GRP2GRP1

PAN

L

R=L

PK!

+6

0

SIG

EXT

IN

GRP

LEVEL

AUX

1

2

3

4

5

6

7

8

L

R

M

5

OO +6

MUTE

IN

OO +6

GRP

1

OO +6

GRP

2

OO +6

GRP

3

OO +6

GRP

4

OO +6

GRP

5

OO +6

GRP

6

OO +6

GRP

7

OO +6

GRP

8

OO +6

L

OO +6

R

OO +6

M

OO +6

LEVEL

OO +6

MUTE

AUX

0

6

+10OO

OO

+10

ST3

LR

ST4

AUX

0

4

+10

EXT IN

GRP

LEVEL

AUX

1

2

3

4

5

6

7

8

7

OO +6

L

OO +6

R

OO +6

M

OO +6

MUTE

OO

EXT IN

OO +6

GRP

1

OO +6

GRP

2

OO +6

GRP

3

OO +6

GRP

4

OO +6

GRP

5

OO +6

GRP

6

OO +6

GRP

7

OO +6

GRP

8

OO +6

L

OO +6

R

OO +6

M

OO +6

LEVEL

OO +6

MUTE

AUX

0

8

OO

+10

TALKBACK MIC

TALKBACK

MAXMIN

OSC/NOISE

MAXMIN

PINK NOISE 1kHz OSC

ON

M

L-R

MTX1-2

MTX3-4

AUX 1-2

AUX 3-4

AUX 5-8

AUX 9-10

LATCH

TALK

AUX

9-10

STEREO

MUTE

+10OO

+10

MUTE GROUPS

GRP4GRP3

GRP5

GRP6

GRP7

TO LRTO LR

TO LR

PAN

R=L

PK!

+6

0

SIG

PAN

R=L

PK! +6

0

SIG

TO LR

R=L

PAN

PK! +6

0

SIG

TO LR

R=L

GRP8 TO LR

=

PAN

PK! +6

0

SIG

L-R TO M

R

MUTEMUTEMUTEMUTEMUTEMUTEMUTE MUTEMUTE

0dBOO

PK!

+6

0

SIG

AFLAFLAFLAFLAFLAFLAFLAFL

GRP8

GRP7

GRP6

GRP5

GRP4

GRP3

GRP2

GRP1

10

5

0

5

10

20

30

00

AUX2AUX1

10

5

0

5

10

20

30

00

AUX4

AUX3

10

5

0

5

10

20

30

00

AUX6

AUX5

10

5

0

5

10

20

30

00

AUX8

AUX7

10

5

0

5

10

20

30

00

L

AUX9-10

10

5

0

5

10

20

30

00

M

R

LISTEN

10

5

0

5

10

20

30

00

+48V

POLARITY

LINE

(PAD)

0

30

40

20

GAIN

50

4k

6k

250

400

R

HF

12k

HM

LM

LF

80Hz

AUX

1

AUX

2

AUX

3

AUX

4

AUX

5

AUX

6

AUX

7

AUX

8

AUX

9-10

STEREO

PAN

-15

1k

700

500Hz

-15

70

45

35Hz

-15

OO +6

ODD

3k

180

OO +6

=

L R

=

L

60 40-14 6

HPF

100Hz

+15

4k

15k

+15

250

1k

+15

EQ IN

PRE-EQ

POST PRE

+6OO

POST PRE

R

EVEN

MUTE

PFL

PK! +6

0

SIG

10

M

5

L-R

0

1-2

5

3-4

10

5-6

7-8

20

M1

30

M2

M3

00

M4

+48V

POLARITY

LINE

(PAD)

0

30

40

20

GAIN

50

6k

400

60 40-14 6

HPF

100Hz

STEREO STEREO

-5

-10

GAIN

-20

-30

16

O

HF

12k

+15-15

HM

2k5

+15-15

LM

250Hz

+15-15

LF

80Hz

+15-15

EQ IN

AUX

1

+6OO

AUX

2

AUX

3

+6OO

AUX

4

+6OO

POST PRE

AUX

5

+6OO

AUX

6

OO +6

AUX

7

OO +6

AUX

8

+6OO

POST PRE

AUX

9-10

STEREO

+6OO

=

BAL

POST PRE

=

BAL

L

ODD

EVEN

MUTEMUTE

PFL

PK! +6

0

SIG

10

M

5

L-R

0

1-2

5

3-4

10

5-6

7-8

20

M1

30

M2

M3

00

M4

50

0

5

RL

R

6 GL2800 User Guide

MRL87654321

The Range:

GL2800-24 22 mono mic/line, 2 mic/ stereo line, 2 dual stereo returns

GL2800-32 30 mono mic/line, 2 mic/ stereo line, 2 dual stereo returns

GL2800-40 38 mono mic/line, 2 mic/ stereo line, 2 dual stereo returns

GL2800-48 46 mono mic/line, 2 mic/ stereo line, 2 dual stereo returns

GL2800-56 54 mono mic/line, 2 mic/ stereo line, 2 dual stereo returns

RPS11 Power Supply

GL2800-SLV2 Sys-Link V2 console in/out expander option kit

OUT

L/M

L

LAMP LAMP

MONITOR

OUT

RL

(WEDGE)MOUT

R

INSERT

M

TB/GEN

OUT

LROUT

OUT

(9)(10)

MTXMTX MTX MTX

IN IN IN IN

3421

MTX OUT

4

INSERTLINSERT8INSERT7INSERT INSERT

R

AUX AUX

10

3

AUX AUX7AUX

(L)(R)

9

8

MTX OUT1MTX OUT

2

MATRIX EXT IN

IN2TRK

(COMMON)

L/MRL/M L/M L/M

INSERT

5

6

AUX

6

5

ST1 IN

ST2 INST3 INST4 IN

INSERT

2

3

4

AUX

2

3

4

GRP 2(AUX)(AUX)GRP(AUX)GRP(AUX)GRP(AUX)GRP(AUX)GRP(AUX)GRP 345678 (AUX) 1GRP

DIRECT

OUT

INSERT

R

RETURN

DIRECT

INSERT

MIC OUT

(BREAKPOINT)

STEREO LINE IN

L/M

R

MIC IN

INSERT

SEND

TIP

RING

OUT

USE ONLY THE RECOMMENDED ALLEN & HEATH POWER SUPPLY

DC POWER IN DC POWER IN

A

DIRECT

OUT

INSERT

DIRECT

OUT

INSERT

LINE IN

MIC IN

DIRECT

OUT

INSERT

DIRECT

INSERT

LINE IN

MIC IN

OUT

B

(BACKUP)

DIRECT

OUT

INSERT

DIRECT

INSERT

LINE IN

MIC IN

DIRECT

OUT

INSERT

LINE IN

MIC IN

INPUT

+IN

1

2

DIRECT

INSERT

MIC

- IN

3

TIP +INTIP

LINE

RING -INRING

DIRECT

OUT

INSERT

DIRECT

OUT

INSERT

LINE IN

MIC IN

SERIAL NUMBER

DIRECT

OUT

INSERT

LINE IN

MIC IN

ALLEN & HEATH LIM ITED

MIC OUT

(BREAKPOINT)

STEREO LINE IN

L/M

(GRP/AUX REVERSE)

DIRECT

OUT

INSERT

MIC IN

1

AUX

(GRP)(GRP)(GRP)(GRP)(GRP)(GRP)(GRP)(GRP)

1

LINE IN

MIC IN

LINE IN

SYS-LINK V2 CONSOLE EXPANDER INPUT ( option )

LINE IN

INPUT BINPUT A

LINE IN

MIC INMIC INMIC INMIC INMIC INMIC INMIC IN

GL2800 User Guide 7

Introducing the Allen & Heath GL2800

The GL2800 is an 8-bus dual function analogue mixing console designed for professional audio applications. Whether mixing FOH, monitors or both, recording live or in the studio, installed in a busy venue, out on the road touring, or earning its keep in rental stock, the GL2800 provides the perfect solution. Engineered to the same exacting standards as our top of the range consoles it ensures the highest reliability and finest sonic performance. We have taken the outstanding success of our industry leading GL consoles and provided yet more innovative capability and enhanced performance for modern mixing.

• 24, 32, 40, 48, 56 channel frames

• L, R and M mix buses

• 8 audio groups with pan and routing to LR and M

• 10 Auxes including a dedicated stereo send

• 12x4 matrix with full stereo capability

• 2 Stereo channels each with mic and stereo line inputs

• 2 extra dual stereos provide 4 summed or independent stereo returns

• Proper dual functionality for FOH/monitor mixing

• M can be used for centre, mono sum or sub, or for engineers monitor wedge

• Recording capable with channel direct outputs

• Matrix external inputs with level trim and common input capability

• Stereo channel mic can cross patch into matrix for ambience

• Dual stereo return line inputs can be independently routed to LR

• Responsive 4 band, 2 sweep EQ

• 100Hz channel high pass filters

• Individual phantom power and polarity switching

• Wide angle 4 led channel meters

• Per channel pre/post fader aux switching for unlimited flexibility

• Recessed pre/post-EQ aux switching per channel, no internal access needed

• Internal pluggable jumpers for pre/post-EQ aux and direct out

• Mutes and meters on all fader masters

• Assignable talkback to all outputs

• 1kHz oscillator / pink noise generator with external output

• 2 Track monitoring and replay to LR

• 3 Headphones sockets including 3.5mm for IEM

• Dedicated stereo monitor meters

• Electronically balanced XLR outputs with +26dBu drive capability

• Preamp 74dB gain range and +34 maximum input capability

• Ultra low noise mix head amp design

• Uses external linear power supply

• Built-in combiner for redundant power supply

• Metal jacks, gold plated XLRs, sealed pots and switches

• Individual circuit card assembly with nutted pots

• Solid copper bus grounding

• Sys-Link V2 console linking option

• 4-pin XLR lamp sockets

8 GL2800 User Guide

Here are just a few key points we considered when specifying the GL2800:

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 wide viewing angle meter design, the exceptional feature set, or the ‘under the bonnet’ engineering such as the solid copper grounding strip, individual cards, circuit enhancements and more. The result is a nononsense, 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 GL2800 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 smooth travel faders with protective dust covers, 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 external linear power supply has plenty of overhead. You can even plug in a second supply as a backup for added security.

Performance The GL2800 benefits from our latest circuit developments which have

improved the sound and responsiveness of the mic preamp 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 new 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 +26dBu 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 GL2800 takes this an important stage further with its new multiple stereo mix capability. Tamperproof recessed switches configure the console safely for optimum FOH or stage monitor operation, or for mixing monitors from FOH. In FOH mode you get 3 main mix buses L, R and M. You can use M to feed the C in an LCR system, to create a mono fill by summing L and R, or even drive a sub-bass speaker system. 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 8 subgroups to LRM, and the groups/LRM feeding the matrix for yet more mixes. The fully featured 12x4 matrix is a valuable addition. For example, in FOH mode you can create independent fill speaker and acoustics compensated recording feeds, even capturing the atmosphere by cross patching the stereo channel mic preamps into the matrix to add individual or common mono or stereo ambience signals. In MONITOR mode the matrix gives you more monitor outputs easily created from the groups and LR with added ‘more me’ and ambience for the in-ear application. This compact console can feed up to 14 independent mixes, for example 8 wedges and 3 true stereo IEM. We have also considered the RECORDING application with direct outputs on all mono channels, 8 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, the built-in tone/pink noise generator for system checking, full channel and main output metering, the multifunctional stereo channel and return strips, Sys-Link V2 console expansion… and much more. We hope you enjoy being as creative using the GL2800 as our team enjoyed creating it.

Carey Davies, Head of Design, and sound guy too…

GL2800 User Guide 9

Installing the Console

The GL2800 has a space saving, compact chassis design. This is convenient both in saving seats for the paying audience in a busy venue, and in reducing the size, complexity and weight of flight casing for on-the-road use. The control surface has a 10 degree slope for optimum visibility during operation. The rear connector panel has a split angle design for ease of plugging and unplugging the connectors.

Free Standing The console has rubber feet fitted for free standing operation on a flat

surface. Make sure the surface is well supported, stable and big enough for the console to sit securely on all its feet. Allow enough space behind the console for access to its connectors.

Flight Casing The console is shaped for easy flight casing. Make sure it is supported

on all sides using suitably thick, shock absorbent foam intended for this purpose. Ensure no part of the case or its lid touches the controls or connectors. If you include a rear ‘doghouse’ to house the connections make sure the cables can be supported in a way that prevents putting stress on the console connectors. To prevent transit damage through inadequate protection, we recommend you have the flight case supplied or approved by a professional, specialist equipment case manufacturer.

Do not obstruct the heatsinks or ventilation openings on the power unit. Ensure adequate air flow around its surfaces. To avoid audible hum, buzz or other performance degradation, do not place equipment that radiates strong electromagnetic fields such as the power unit, other mains power supplies, amplifiers and computers next to or directly underneath the console.

168

5

9

GL2800-824 = 944

GL2800-832 = 1171

GL2800-840 = 1398

GL2800-848 = 1625

GL2800-856 = 1852

640

6

3

4

62

58

19

MONO

INPUTS x 8

MONO

INPUTS x 8

MONO

INPUTS x 8

MONO I/P x 6

ST I/P x 2

MASTER

SECTION

MONO

INPUTS x 8

MONO

INPUTS x 8

MONO

INPUTS x 8

10 GL2800 User Guide

650

Connecting Power

USE ONLY THE RECOMMENDED ALLEN & HEATH POWER SUPPLY

DC POWER IN DC POWER IN

A

B

(BACKUP)

Read and understand the Important Safety Instructions printed at the start of this guide, and the warnings printed on the rear of the console. Check that your local mains supply voltage is the same as that marked on the rear of the RPS11 power unit. Check that the correct mains lead with moulded plug has been supplied. Make sure that the IEC mains plug is pressed fully into the panel socket on the RPS11 before switching on.

Grounding

The connection to ground in an audio system is important for two reasons:

1. SAFETY - To protect the operator from high voltage electric shock, and

DC FUSES

CAUTION: FOR CONTINUED PROTECTION AGAINST RISK OF FIRE

REPLACE FUSE WITH SAME TYPE AND RATING.

ATTENTION: REMPLACER LE FUSIBLE AVEC UN DES MEMES

CARACTERISTIQUES.

T 10A 250V 20mm

POWER

ON OFF

V+

V-

2. AUDIO PERFORMANCE - To minimise the effect of ground (earth) loops which result in audible hum and buzz, and to shield the audio signals from interference.

For safety it is important that all equipment grounds are connected to mains ground so that exposed metal parts are prevented from carrying high voltage which can injure or even kill the operator. Do not disconnect the ground connection in the mains lead. It is recommended that the system engineer check the continuity of the safety ground from all points in the system including microphone bodies, turntable chassis, equipment cases, rack metalwork and so on.

Connecting the power supply

Connect the DC power lead between the socket labelled “DC OUT” on the RPS11 and the socket labelled “DC POWER IN A” on the GL2800.

Switching the console on and off

It is good practice to turn power amplifiers off before switching the console and any other connected equipment on or off. This prevents any unexpected clicks or thumps when the equipment is powered up.

Turn amplifiers and powered speakers on last and off first.

Turn the console on and off using the power switch on the front of the RPS11 (there is no separate ON/OFF switch on the console itself). The blue power indicator LED on the console front panel will illuminate to show that the console is switched on.

Connecting a backup supply

A second power socket, labelled “DC POWER IN B (BACKUP)” is included for plugging in an optional backup power supply. This provides the reassurance of power supply dual redundancy, a feature usually found only on expensive top end consoles. The console uses diode combining technology so that both supplies can be powered at the same time. One will automatically take over should the other be switched off or stop working. The recommended backup supply for the GL2800 is a second RPS11.

Only use the recommended Allen & Heath power supply unit. Do not attempt to modify any other power unit to work with the console. Do not attempt to modify or extend the DC power cable that comes with the supply.

GL2800 User Guide 11

PIN 2 = HOT

BALANCED

1=ground

XLR male socket

3

2=hot +

INPUTOUTPUT

XLR female socket

21

3

2=hot +

12

1=ground

1+3 = 12V

1

LAMP

BALANCED

3

4 = 0V

RCA phono jacks

Tip

UNBALANCED

Female XLR plug

3=cold -

XLR male plug

UNBALANCED

Ring

Sleeve

TS jack plug

Sleeve

TRS jack plug

INPUT / OUTPUT

UNBALANCED

link Ring to Sleeve

HEADPHONES

Sleeve=ground

Ring=RIGHT

Tip=LEFT

INSERT

231

XLR female plug

132

BALANCED

Sleeve=ground

Ring=cold -

Tip=hot +

AB

SYS-LINK V2 OPTION

UNBALANCED

Sleeve=ground

Ring=return

Tip=send

XLR male plug

13 GRP 4+

12 AUX 1+

11 AUX 2+

10 AUX 3+

9 AUX 4+

8 AUX 5+

7 AUX 6+

6 PFL+

5 AFL+

4 nc

3 PFL DC

2 AFL DC

14 GRP 3+

15 GRP 2+

16 GRP 1+

17 R+

18 L+

19 0V (CHS)

L- 37

R- 36

AUX 1- 31

AUX 4- 28

AUX 5- 27

AUX 2- 30

AUX 6- 26

AUX 3- 29

GRP 4- 32

GRP 3- 33

GRP 2- 34

GRP 1- 35

1 0V (PAFL)

nc 21

nc 23

nc 20

nc 22

PFL- 25

AFL- 24

14 GRP 7+

15 GRP 6+

16 GRP 5+

17 nc

18 M+

19 0V (CHS)

13 GRP 8+

12 AUX 7+

11 AUX 8+

10 AUX 9+

9 AUX 10+

8 nc

7 nc

6 nc

5 nc

4 nc

3 nc

2 nc

1 nc

nc 22

nc 36

M- 37

GRP 5- 35

GRP 7- 33

GRP 6- 34

nc 27

AUX 7- 31

AUX 8- 30

AUX 9- 29

GRP 8- 32

AUX 10- 28

nc 21

nc 23

nc 20

nc 24

nc 26

nc 25

12 GL2800 User Guide

Audio Connections

The GL2800 uses professional grade 3 pin XLR and 1/4" TRS (3 pole) jack sockets. To ensure best performance, we recommend that you use high quality audio cables and connectors, and take time to check for reliable and accurate cable assembly. It is well known that most audio system problems are due to faulty or sub standard interconnecting leads. The following plugs may be used to connect audio to the console:

Avoid reversing + and - on balanced connections as this will result in reversed polarity (out of phase) signals which may cause signal cancellation effects.

Where long cables runs are required, balanced interconnections should be used. However, line level interconnections between more affordable 2-wire (signal, ground) unbalanced equipment and the console are unlikely to cause problems if the cables are kept shorter than 10 metres or so. Refer to the wiring diagrams on the opposite page.

Dealing with Ground Loops, Buzz and Interference

For optimum performance all audio signals should be referenced to a solid, noise-free ground (earth) point, frequently referred to as the ‘star point’ or ‘clean earth’.

A ground loop is created when potential differences exist between grounds at different points in the system, and the signal has more than one path to ground. In most cases ground loops do not result in audible problems. Should you experience hum or buzz caused by a ground loop, check first that each piece of equipment has its own separate path to ground. If so, operate ground lift switches on connected equipment in accordance with the instruction manuals. Alternatively disconnect the cable screen at the destination end only. This breaks the offending loop while keeping the signal shielding down the length of cable.

WARNING For operator safety, do not remove the ground (earth) connection

in the power lead of the console power supply unit or connected equipment.

To avoid interference pickup keep audio cables away from mains power units and cables, lighting cables, thyristor dimmer units, computer equipment and mobile phones. Where this cannot be avoided, cross the cables at right angles to minimise interference

A note about balanced connections

A differentially balanced connection has two signal wires, signal + (hot) and signal - (cold) and a shield. The signal source generates positive going polarity down the + wire and negative polarity down the – wire. The destination input stage accepts the + signal on its non-inverting (+) input pin, but it inverts the – signal, adding it to the + signal. The result is that the wanted signal is boosted. Now examine what happens when unwanted interference (hum and noise) is induced into the cable. The noise is induced equally and with the same polarity into both wires. At the destination input the – wire signal gets inverted and added to the + signal. Because the polarity is the same on both input wires the noise cancels itself out at this input. For this interference rejection to work it is important that the source, the cable and the destination input are all balanced. Balancing provides greatest advantage with low level signals such as those produced by microphones.

An impedance balanced maximum drive capability as the differentially balanced output, typically +20dBu versus +26dBu. It does not generate a negative polarity signal at its – output. Instead, the – wire has no signal but is held at the same impedance as the + wire. This means that both wires pick up the noise equally resulting in the advantage of noise cancellation as described above when connected to a balanced input stage.

output provides similar interference rejection, but not as much

GL2800 User Guide 13