Soundcraft GP1 USER GUIDE

USER GUIDE

© Soundcraft Electronics Ltd.1994

All rights reserved

Parts of the design of this product may be protected by worldwide patents.

Part No ZM0055/01

Information in this manual is subject to change without notice and does not represent
a commitment on the part of the vendor. Soundcraft Electronics Ltd. shall not be
liable for loss or damage whatsoever arising from the use of information or any error
contained in this manual.

No part of this manual may be reproduced, stored in a retrieval system, or transmit­ted, in any form or by any means, electronic, electrical, mechanical, optical,
chemical, including photocopying and recording, for any purpose without the
express written permission of Soundcraft Electronics Ltd.

It is recommended that all maintenance and service on the product should be carried
out by Soundcraft Electronics Ltd. or its authorised agents. Soundcraft Electronics
Ltd cannot accept any liability whatsoever for any loss or damage caused by service,
maintenance or repair by unauthorised personnel.

Soundcraft Electronics Ltd.
Cranborne House,
Cranborne Road,
Cranborne Industrial Estate,
Pottersbar,
Herts.,
EN6 3JN
England.

Tel: [phone]

Fax: [phone]

Table of Contents

Introduction 1

Introduction to the GP1 2

Precautions and Safety Instructions 3

PPS110 Circuit Diagram 6

Connections 7

Block Diagrams 9

Block Diagram - Inputs 10

Block Diagram - Outputs 11

Mono Input Module 13

Mono Input Module 14

Std Stereo Line Input 17

Standard Stereo Line Input Module 18

Basic Stereo Line Input 21

Basic Stereo Line Input Module 22

Master Section 25

Master Section 26

Monitor Module 29

Monitor Module 30

Appendices 33

Technical Specifications 34

Dimensions 35

Warranty 36

Introduction

Introduction 1

Introduction to the GP1

Overview

The GP1 Location Broadcast Mixer is available in three frame sizes: 6, 8 and 12
Input Modules. The GP1 also has an Output & Meter Master Module ,and a Monitor
Module.

The Output meters are VU or PPM.

The GP1 is lightweight, for portability, whilst also being rugged.

The power consumption is low to ensure a long usable life for the internal batteries
(typically 8-10 hrs from Ni-Cd cells, and 15-20 hrs from alkaline cells - both figures
for the 12 Input version).

Although the GP1 is primarily designed for remote use with on-board battery power,
the mixer may also be rack mounted (8 Input variant only), or furniture mounted. It
may be mains powered via the PPS110 power supply.

2 Introduction

Precautions and Safety Instructions

General Precautions Avoid subjecting the mixer to conditions of excessive heat or cold, or installing it

in positions where it is likely to be subject to vibration, dust or moisture. Do not use
any liquids to clean the fascia of the unit: a soft dry brush is ideal. Use only water
or ethyl alcohol to clean the trim and legend strips. Other solvents may cause damage
to paint or plastic parts.

Avoid using the mixer close to strong sources of electromagnetic radiation (e.g.
video monitors, high-power electric cabling): this may cause degradation of the
audio quality due to induced voltages in connecting leads and chassis. For the same
reason, always site the mixer power supply away from the mixer.

Caution! In all cases, refer servicing to qualified personnel.

Power supply & cables Always use a power supply and power cables specified for the mixer: the use of

alternative supplies may cause damage and voids the warranty; the extension of
power cables may result in malfunction of the mixer.

Warning! Before switching on the power supply, check that the mains voltage selectors

are correctly set to the voltage for your area, and that the fuses are of the correct
type and rating. This is marked on the case of the power supply. Do not replace
the fuses with any other type, as this could become a safety hazard and will
void the warranty.

PPS110
Power Supply

Warning! Always switch the power supplies off before connecting or disconnecting the

mixers power cables, removing or installing modules, and servicing. In the
event of an electrical storm, or large mains voltage fluctuations, immediately
switch off the PSU and isolate from the mains. The power supply is connected
to the mixer via the 4-way socket, marked DC Power, on the rear panel.

Always ensure that you use a suitable power supply for the mixer. The GP1 may
use a PPS110 power supply (see details of the power connection below), or a suitable
external source.

The mixer is powered from an external power supply when the POWER switch on
the rear panel is set to EXT.

A PPS110 power supply is supplied with all variants of the GP1. The power supply
is capable of operating over a wide range of mains input voltages by means of a
comprehensive set of selectable voltage settings. It is important to ensure that the
correct voltage setting has been selected for the level of local AC mains input voltage
supply, for safe, uninterrupted-operation of the units.

Warning! DO NOT CHANGE THE AC MAINS VOLTAGE SETTING WITHOUT

FIRST DISCONNECTING THE MAINS PLUG FROM THE MAINS
SOCKET.

The power supply is provided with an IEC-type mains connector, coupled with a
voltage selector with integral AC mains fuse holder. Confirm that the arrow
moulded into the connector unit aligns with the voltage setting that is correct for
your area. Voltage selection should be as follows:

· 100Volt setting for AC Mains Input 100-115Volts AC

· 120Volt setting for AC Mains Input 115-125Volts AC

· 220Volt setting for AC Mains Input 210-225Volts AC

Introduction 3

· 240Volt setting for AC Mains Input 230-264Volts AC

To change the selected voltage, prise off the fuse holder square top with a screw­driver-type tool, using the square blade tip in the slot. Pull the fuse carrier assembly
clear of the body, rotate the fuse carrier body until the required input voltage lines
up with the arrow, and then push the fuse carrier back into the connector body.

Warning! DO NOT USE DC MAINS INPUT VOLTAGES

Replacing Mains Fuse Switch the units on/off mains switch to the off position, remove the mains lead plug

from the mains supply socket.

Check the fuse and replace if necessary: also check that the voltage selector is correct
for the mains supply level before switching the unit on again. The correct fuse ratings
are as follows:

220/240 VAC fuse rating T1.0A/250V

100/120 VAC fuse rating T2.0A/250V

Warning! TO AVOID THE RISK OF FIRE REPLACE ONLY WITH THE CORRECT

VALUE AND TYPE OF FUSE AS INDICATED ON THE UNIT.

In the event of repeated failure of the mains fuse, consult the dealer from whom the
unit was purchased.

Technical Specification Mains Input Voltages (Nominal): 240/220/120/100 VAC @50/60Hz

PPS110 XLR pin out:

Pin 1 Chassis

Pin 2 0V

Pin 3 Battery charging voltage (28V DC (nominal))

(for charging the internal batteries)

Pin 4 28V DC ( nominal)

Overall Dimensions (Chassis)

Height: 77mm

Width: 140mm

Depth: 172mm

Power Supply Installation Free Standing

The PPS110 is designed to operate as a free-standing unit without requiring any
special cooling arrangement, but should not be accidentally or deliberately covered
in any way.

Rack Mounting

The PPS110 can be provided with an optional 19-inch rack-mounting kit: it occupies
2U of rack space.

Batteries The Location Mixer may also be powered by its own internal batteries: 12 or 16 D

type cells are required: the 6 and 8-input variants use 12 cells, the 12-input variant
uses 16 cells. These may be primary cells or rechargeable cells; all cells must be of

4 Introduction

the same type, do not mix types. The access panel for inserting and removing the
cells is on the underside of the mixer.

Warning! DO NOT try to recharge dry (primary cells: they may explode, and the wiring

will melt if this is attempted

Rechargeable cells may be recharged from the power supply. To do this set the
CHARGE switch on the power supply to on.

It is not advisable to charge the cells and use the mixer at the same time: performance
specifications may not be achieved under adverse conditions.

The mixer is powered from the internal cells when the POWER switch on the rear
panel is set to INT.

Signal Levels It is important to supply the correct input levels to the mixer, otherwise signal-to-

noise ratio or distortion performance may be degraded, and in extreme cases damage
to the internal circuitry may result. Likewise, on all balanced inputs, avoid sources
with large common mode DC, AC or RF voltages, as these will reduce the available
signal range on the inputs. Note that 0dBu = 0.775V RMS.

The microphone inputs are designed for use with balanced, low impedance (150 or

200) microphones.

Caution! DO NOT use unbalanced microphones or battery powered condenser microphones

without isolating the phantom power - degraded performance or damage to the
microphone may result.

Introduction 5

PPS110 Circuit Diagram

LD1

R3
2K4

CHARGE

F4

CHARGE

SW1

SPST

CN2

F1A

1

2 P IN

2

AMBER

F3

F3,16A

DC

0V

CHASSIS

DC

CHARGE

1

2

3

4

5

L1

2U2H

5 P IN

CHOKE

R4

2K4

10000/40V

CN3

D1

1N4001

C5

LD2

GREEN

4 P IN XL R

CABLE CONNECT OR

DC

4

1

RED

WHT

YEL

CHASSIS

CHARGE

0V

GREEN

3
2

PPS-110

UNREGULATED POWER SUPPLY

ISSUE 2

ED3395

240V

C4

10000/40V

C3

2U2F/50V

!

F2

3,15A

F1

3,15A

CN1

4 P IN

123

R2

22R

C2

100N

0.5W

4

C1

100N

R1

47R

RECT1

!

18V5 AC

!

TRANSFORMER

T1

!

0V

220V

120V

100V

DPST

SW2

MAINS VOLTAGE

!

50/60Hz

100V-240V

!

LNE

(I.E.C)

SELECTOR

120V

220V

100V

240V

F5

FUSE

!

A.C.

The Mains input fuse is rated at:

T1.0A/250V Mains Input 220/240V AC

T2.0A/250V mains Input 100/120V AC

CHASSIS

6 Introduction

Connections

Wiring Conventions The GP1 uses two different types of audio connector: 3-pin XLR, and

jacks.

XLR Connectors

MALE XLR

12

3

Pin 1 = Ground (Screen)
Pin 2 = Hot (In-Phase)
Pin 3 = Cold ( Out-Of-Phase)

FEMALE XLR

1

Pin 1 = Ground (Screen)
Pin 2 = Hot (In-Phase)
Pin 3 = Cold ( Out-Of-Phase)

2

3

Jack Plugs

1

/4" 3-pole

Tip Ring Sleeve

The Connections are as follows:

Balanced Inputs

Tip Hot (In-Phase) Signal

Ring Cold (Out-Of-Phase) Signal

Sleeve Ground (Screen)

Headphones

Tip Left Signal

Ring Right Signal

Sleeve Ground (Screen)

Introduction 7

8 Introduction