Allen and Heath GL-3800 Owners manual

ALLEN&HEATH

GL3800

USER GUIDE

Publication AP6157

Limited One Year Warranty

This product has been manufactured in the UK by ALLEN&HEATH and 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.

GL3800 User Guide AP6157 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 GL3800 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.

GL3800 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 GL3800 User Guide

Introduction

Welcome to the Allen & Heath GL3800, 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 GL3800............................. 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 GL3800....................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

GL3800 User Guide 5

LAMP LAMP

+48V

POLARITY

LINE

(PAD)

0

30

40

20

GAIN

50

60

40-14 6

HPF

100Hz

HF

12k

-15

+15

3k

4k

1k

6k

700

15k

500Hz

HM

+15

-15
180

250

70

400

45

1k35Hz

LM

+15

-15

LF

80Hz

+15

-15

EQ IN

AUX

1

+6

AUX

2

PRE-EQ

PRE-EQ

AUX

3

+6

AUX

4

+6

POST
PRE

AUX

5

+6

AUX

6

+6

AUX

7

+6

AUX

8

+6

POST
PRE

AUX

9-10

STEREO

+6

=

PAN

RL

POST
PRE

=

PAN

R

L

ODD

EVEN

MUTE

PFL

PK!
+6

0

SIG

10

5

M

0

L-R

5

1-2

3-4

10

5-6

20

7-8

+48V

POLARITY

LINE

GAIN

9-10

STEREO

(PAD)

0

30

40

20

50

60 40-14 6

HPF

100Hz

HF

12k

-15

+15

3k

4k

1k

6k

700

15k

500Hz

HM

+15

-15
180

250

70

400

45

1k35Hz

LM

+15

-15

LF

80Hz

+15

-15

EQ IN

AUX

1

+6

AUX

2

PRE-EQ

PRE-EQ

AUX

3

+6

AUX

4

+6

POST
PRE

AUX

5

+6

AUX

6

+6

AUX

7

+6

AUX

8

+6

POST
PRE

AUX

+6

=

PAN

RL

POST
PRE

=

PAN

R

L

ODD

EVEN

STEREO

GAIN

STEREO

GAIN

9-10

PK!
+6

SIG

0

-5

ST1

5

-10

10

-20

16

DIRECT TO

LR

0

-5

ST2

5

-10

10

-20

16

AUX

1

+6

AUX

2

+6

AUX

+6

MUTE

PFL

10

M

5

L-R

0

1-2

5

10

20

30

AUX

0 0

1

2

+10

AFL

GRP1
TO M

TO LR

=

PAN

PAN

L

R

PK!
+6

0

0

SIG

MUTE

PFL

PK!
+6

0

SIG

10

5

M

0

L-R

5

1-2

3-4

10

AFL AFL AFL AFL AFL AFL AFL AFL

GRP1

AUX1 AUX2

10

10

5

5

0

0

5

5

10

10

5-6

20

7-8

20

20

GL3800

DUAL FUNCTION AU DIO MIXING CONSOLE

DUAL STEREO RETURNDUAL STEREO RETURN

STEREO

0

-5

GAIN

5

-10

10

-20

16

DIRECT TO

STEREO

0

-5

GAIN

5

-10

10

-20

16

AUX

1

+6

AUX

2

+6

AUX

9-10

+6

MUTE

PFL

10

M

5

L-R

0

3-4

5

10

20

30

AUXAUX

0

3

+10

+10

AFL AFL AFL AFL AFL AFL AFL

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

GRP2GRP1
TO LR

TO LR

=

=

PAN

L R

PK!
+6

0

SIG

GRP2

GRP3

AUX3

10

5

0

5

10

20

EXT

EXT
IN

GRP

GRP

GRP

GRP

GRP

GRP

GRP

GRP

LEVEL

AUX

EXT
IN

+6

+6

GRP

1

1

+6

+6

GRP

2

2

+6

+6

GRP

3

3

+6

+6

GRP

4

4

+6

+6

GRP

5

5

+6

+6

GRP

6

6

+6

+6

GRP

7

7

+6

+6

GRP

8

8

+6

L

R

M

6

+6

L

+6

+6

R

+6

+6

M

+6

+6

LEVEL

+6

+6

AUX

0

7

+10

+10

IN

ST3

LR

ST4

AUX

4

+6

GRP

1

+6

GRP

2

+6

GRP

3

+6

GRP

4

+6

GRP

5

+6

GRP

6

+6

GRP

7

+6

GRP

8

+6

L

+6

R

+6

M

+6

LEVEL

+6

MUTE

AUX

0

0

5

+10

+10

REV

GRP4GRP3

GRP5

GRP6

TO LR

=

PAN

L

PK!
+6

0

SIG

GRP4

10

5

0

5

10

20

TO LR

=

PAN

RL R

PK!
+6

0

SIG

GRP5

AUX4

10

5

0

5

10

20

=

PAN

RL

PK!
+6

0

SIG

GRP6

AUX5

10

5

0

5

10

20

TO LR

GRP7
TO LR

=

PAN

RL

RL

PK!
+6

0

SIG

GRP7

AUX6

AUX7

10

5

0

5

10

20

EXT
IN

GRP

1

GRP

2

GRP

3

GRP

4

GRP

5

GRP

6

GRP

7

GRP

8

L

R

M

LEVEL

MUTEMUTEMUTE

AUX

0

8

TALKBACK MIC

+6

+6

TALKBACK

+6

+6

+6

+6

+6

+6

OSC/NOISE

ON

M

L-R

MTX1-2

MAXMIN

MAXMIN

PINK NOISE
1kHz OSC

MTX3-4

+6

AUX

9-10

STEREO

1-2

AUX
3-4

AUX
5-8

AUX
9-10

LATCH

TALK

AUX

00

+10

MUTE

+6

+6

+6

+6

+10

REVREV REVREVREVREVREVREV

ROTARIES

AUX MODE

FOH
MONITOR

FADERS

GRP8
TO LR

=

PAN

PK!
+6

0

SIG

GRP8

10

5

0

5

10

20

L-R TO M

RL

MUTEMUTEMUTEMUTEMUTEMUTEMUTE MUTEMUTE

AUX8

0dB

PK!

PK!

+6

+6

0

0

SIG

SIG

L

AUX9-10

10

10

5

5

0

0

5

5

10

10

20

20

1 2

STEREO

STEREO

MUTE GROUPS

M

P/AFL

PK!
+6

0

SIG

R

10

5

0

5

10

20

PHONES

2TRK REPLAY

POWER

L

PFL/AFL

MONITOR

MONITOR

+16

+9
+6
+3

-12

-16

-20

-30

M

0

-3

-6

-9

M

L-R

2TRK

MTX1

MTX2

MTX3

MTX4

AUX
9-10

WEDGE
MODE

+10

2TRK
TO LR

100

LISTEN

UNDER

ARMREST

R

PK!
+6

SIG

GAIN

STEREO

GAIN

250Hz

9-10

STEREO

0

L-R

1-2

3-4

5-6

7-8

HF

12k

HM

2k5

LM

LF

80Hz

AUX

1

AUX

2

AUX

3

AUX

4

AUX

5

AUX

6

AUX

7

AUX

8

AUX

BAL

BAL

M

0

20

-10

-20

-30

-15 +15

-15 +15

-15 +15

-15 +15

L R

ODDLEVEN

30

-5

=

=

+48V

POLARITY

LINE

(PAD)

40

60 40-14 6

HPF

100Hz

16

EQ IN

+6

+6

+6

+6

POST
PRE

+6

+6

+6

+6

POST
PRE

+6

POST
PRE

R

MUTE

PFL

10

5

0

5

10

20

+48V

POLARITY

LINE

(PAD)

0

30

40

20

GAIN

50

0

5

STEREO

GAIN

50

60 40-14 6

HPF

100Hz

-5

-10
0

-20

5

-30

16

HF

12k

-15 +15

HM

2k5

-15 +15

LM

250Hz

-15 +15

LF

80Hz

-15 +15

EQ IN

AUX

1

+6

AUX

2

+6

AUX

3

+6

AUX

4

+6

POST
PRE

AUX

5

+6

AUX

6

+6

AUX

7

+6

AUX

8

+6

POST
PRE

AUX

9-10

STEREO

+6

=

BAL

L R

POST
PRE

=

BAL

R

ODDLEVEN

MUTE

PFL

PK!
+6

0

SIG

10

5

M

0

L-R

5

1-2

3-4

10

5-6

20

7-8

30

M1

M2

M3

M4

30

M1

30

30

30

30

30

30

30

30

30

30

30

M2

M3

M4

1615

GRP

12345678

12345678

LRM

910AUX

LISTEN WEDGE

M1

M2

M3

M4

30

M1

M2

M3

M4

17 18

30

6 GL3800 User Guide

The Range:

GL3800-824m 24 channels, 2 dual stereo returns

2TRK
OUT

MONITOR OUT

R

L

OUT M(WEDGE)

TB/OSC

OUT

(10) (9)OUT R LOUT 8GRP(AUX)

L/M

R

INSERT

MATRIX IN

(INDIVIDUAL OR COMMON)

2TRK

IN

INSERT

RRM

10

GL3800-832m 32 channels,

GL3800-840m 40 channels, 2 dual stereo returns

GL3800-848m 48 channels, 2 dual stereo returns

RPS11 Power Supply

GL3800-SLV2 Sys-Link V2 console in/out expander option kit

L/M

IN

3

4

MTX

MTX

OUT

OUT

INSERT

L

AUXAUX

(R) (L)

9

(AUX)

7GRP (AUX) 6GRP (AUX) 5GRP (AUX) 4GRP (AUX) 3GRP (AUX) 2GRP (AUX) 1GRP

*

1

2

MTX

MTX

OUT

OUT

INSERT

8

8

INSERT5INSERT4INSERT3INSERT2INSERT1INSERTINSERT

6

7

AUX

AUXAUX

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

7

R COMMON L/M

6

1234

*

IN

IN

IN

L/M

ST3

ST4

RR

R

AUX4AUX3AUX2AUX1AUX

5

2 dual stereo returns

m = A all mono channels

B 4 stereos to right of masters

C 4 stereos on right of console

D 8 stereos on right of console

L/M

L/M

ST2

STEREO

ST1

INPUTS

METERPOD

TIP +

INSERT

SEND

RETURN

TIP

RING-

RING

(GRP/AUX REVERSE)

LINE

+

1

2

MIC

-

3

DIRECT

DIRECT

OUT

OUT OUT

INSERTINSERT

LINE IN

LINE IN

MIC IN

MIC IN

DC POWER IN

A

(MAIN) (BACKUP)

USE ONLY THE RECOMMENDED ALLEN & HEATH POWER SUPPLY

DIRECT

INSERT

LINE IN

MIC IN

B

DIRECT

OUT

OUT

INSERT

LINE IN

MIC IN

ALLEN&HEATH

SERIAL No

DIRECT

LINE IN

MIC IN

A

DIRECT

OUT

OUT

INSERTINSERT

LINE IN

MIC IN

GL3800

(option)

SYS-LINK V2

OUTPUT

MADE IN ENGLAND BY ALLEN & HEATH LIM ITED

DIRECT

INSERT

LINE IN

MIC IN

DIRECT

OUT

INSERT

LINE IN

MIC IN

B

DIRECT

DIRECT

DIRECT

INSERT

LINE IN

MIC IN

DIRECT

OUT

OUTOUT

INSERT

LINE IN

MIC IN

DIRECT

LINE IN

MIC IN

DIRECT

OUT

INSERTINSERT

LINE IN

MIC IN

OUT

OUT

INSERT

INSERT

LINE IN

LINE IN

MIC IN

MIC IN

A

(option)

SYS-LINK V2

INPUT

OUT

INSERT INSERT

LINE IN

LINE IN

MIC IN

MIC IN

OUT

B

DIRECT

DIRECT

GL3800 User Guide 7

Introducing the Allen & Heath GL3800

The GL3800 is a large format 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 GL3800 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 channel frames with A, B, C, D stereo channel options

• 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

• Stereo channels each with mic and stereo line inputs – options for 0, 4 or 8 stereos

• 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

• Integral LED-illuminated moving coil VU meter pod

• 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

• 100mm top grade dual rail faders

• 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 GL3800 User Guide

Here are just a few key points we considered when specifying the GL3800:

Choice Our goal has been to provide a truly professional range of consoles to satisfy

your mixing needs, whatever the application. The GL3800 is not only available in 4
different frame sizes, but also 4 different mono/stereo channel combinations for each size…
that is a choice of no less than 16 variants! You can even extend the number of channels
feeding the mix by linking two consoles using our Sys-Link option. The feature set is
bristling with innovative capability that lets you work the way you want.

Reliability

professional application. The GL3800 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, long life
premium grade dual rail faders, metal bodied jacks, 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. A socket is available to plug in a
second supply as a backup for added security.

Without doubt, the most important quality for any equipment intended for the

Performance The GL3800 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 GL3800 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 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 neat, colour coded layout, the practical, 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, both LED and VU
metering, the multi-functional stereo channel and return strips… and much more. We hope
you enjoy being as creative using the GL3800 as our team enjoyed creating it.

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

GL3800 User Guide 9

Installing the Console

The GL3800 has a robust, all metal chassis design. It is convenient both for fixed
installation and flight casing. The control surface has a 10 degree slope for optimum
visibility during operation. The rear connector panel is recessed and angled 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 and along the rear extruded beam 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 console power unit, other mains power supplies,
amplifiers and computers next to or directly underneath the console.

275

0

5

6

9

4

78

35

691

GL3800-824 = 1026

GL3800-832 = 1281

GL3800-840 = 1536

GL3800-848 = 1791

80

MASTER
SECTION

INPUTS x 8INPUTS x 8INPUTS x 8INPUTS x 8INPUTS x 8

INPUTS x 8

10 GL3800 User Guide

691

Connecting Power

DC POWER IN

A

(MAIN) (BACKUP)

USE ONLY THE RECOMMENDED ALLEN & HEATH POWER SUPPLY

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

B

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 GL3800.

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 GL3800 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.

GL3800 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

Tip

UNBALANCED

Female XLR plug

3=cold -

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 GL3800 User Guide

Audio Connections

The GL3800 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

GL3800 User Guide 13

RETURN

SEND

GROUND

The Console Connectors

MONO CHANNEL MIC / LINE IN The LINE (PAD) switch selects

DIRECT

OUT

INSERT

LINE IN

MIC IN

MIC OUT

(BREAK

POINT)

STEREO LINE IN

L/M

R

MIC IN

INSERT

TIP

RING

LINK RING TO SLEEVE TO UNBALANCE

TB/OSC

SEND

RETURN

RETURN

SEND

OUT

PROCESSOR

LAMP

either the MIC XLR or the LINE TRS jack as the input source. The XLR is
normalled through the TRS jack so that it can be used for microphone or
line level signals when nothing is plugged into the jack socket. This gives
the channel preamp a massive headroom with +34dBu maximum input
capability using XLR or jack. Both inputs are balanced but can be wired
to work with unbalanced signals when
required. The MIC XLR can be switched to
provide +48V DC via 6k8 ohm resistors to
pins 2 and 3 for microphones such as
condensers which require phantom powering.

WARNING: Do not connect unbalanced sources or cables to

the XLR input when 48V phantom power is selected. To avoid loud
clicks always turn the channel off by pressing MUTE when switching
+48V on or off, and when plugging or unplugging cables.

STEREO CHANNEL MIC IN Each stereo channel fitted features a

mono microphone XLR input and an independent stereo line input. The
balanced MIC input accepts a maximum +14dBu and can be switched to
provide 48V phantom power.

STEREO CHANNEL MIC OUT The output of the mic preamp is

available on the MIC OUT (BREAKPOINT) TRS jack socket. This is
impedance balanced and operates at a nominal 0dBu line level.

Plugging into this socket breaks the signal into the associated stereo
channel. This means that the mic preamp can be used independently of

the channel, for example to create an ambience mic feed for recording, or
as a preamp for an RTA measurement system.

STEREO CHANNEL LINE IN These inputs are balanced on TRS

jacks. The L input is normalled through the R socket to accept mono
signals on a single jack.

INSERT A single 3-pole TRS jack carries the unbalanced insert signal

for each mono channel and main mix output. Tip = send, Ring = return,
Sleeve = common ground. The channel inserts are post-HPF, pre-EQ

OUT

and operate at 0dBu. The group (aux) and LRM mix inserts are pre-fader
and operate at -2dBu. Use these to patch in line level signal processing
equipment such as compressors, outboard EQ, delay units and so on.
The wiring of a suitable cable is shown in the diagram.

IN

DIRECT OUTPUT Each mono channel direct output is available on

an impedance balanced TRS jack providing a line level signal operating at
0dBu. The source is set using an internal option jumper for each channel.
The factory default setting is pre-fade (following the pre/post-EQ setting).
This may be changed to post-fade if preferred.

TB/OSC OUTPUT Use this to provide an external talkback feed, or

to access the console 1kHz oscillator / pink noise generator. You can
patch this into other inputs or equipment as a test signal.

LAMP The console has two 4pin XLR sockets to plug in standard 12V

gooseneck lamps to illuminate the operating surface when working in a
dark environment. Only use lamps intended for this purpose. We
recommend the Allen & Heath LEDlamp with cool white LED illumination
and a built in dimmer.

INPUT

+IN

TIP +INTIP

RING -INRING

1

3

MIC

- IN

LINE

2

14 GL3800 User Guide