
CONTENTS
1 INTRODUCTION
1.1 Introduction
1.2 Serial Number
1.3 Warning
1.4 Caution
1.5 Attention
2 FRONT PANEL
2.1 On/Off
2.2 Power Indication
2.3 Protect
2.4 Bridge
2.5 Level
2.6 LED Display
3 REAR PANEL
3.1 AC Input
3.2 Fuse
3.3 Signal Output
3.4 Ground Switch
3.5 Cooling Fan
3.6 Signal Input
3.7 Bridge Switch
4 INSTALLATION
4.1 Unpacking
4.2 Mounting
4.3 Cooling Requirements
4.4 Cable Looms
4.5 Power Requirements
4.6 Voltage Selection
4.7 AC wiring
4.8 Balancing Option
4.9 Balanced Signal - A Description
4.10 Input Connections - Balanced
4.11 Input Connections - Unbalanced
4.12 Speaker Wire
4.13 Output Connections
4.14 Signal Matching
4.15 Grounding
5 OPERATION
5.1 Power Up
5.2 Power Down
5.3 Power Loss
5.4 Stereo Mode
5.5 Mono Parallel Mode
5.6 Mono Bridged Mode
5.7 Protection
5.8 Cleaning
6 PERFORMANCE & SPECIFICATIONS
6.1 General Specifications
6.2 Stereo Specifications
6.3 Mono Specifications

1. INTRODUCTION
1.1 Introduction
The RA Series of amplifiers from C Audio combine a variety of power formats in a
uniform low-profile package, incorporating considerable knowledge and expertise
accumulated over many years involvement in the art of Amplifier design and manufacture.
Modern power amplifiers are sophisticated pieces of electronic engineering capable
of producing extremely high power levels. They must be handled with respect and
correctly installed if they are to provide you with many years of reliable service. They
are potentially extremely dangerous if abused, misused or incorrectly installed.
Please take a little time to study this RA Series manual, in order that you can get the
best service from the amplifier.
1.2 Serial Number
Every RA Series amplifier has an individual serial number which is marked on the
back of the unit. Make a separate note of this number somewhere safe where you can
refer to it. You may need to know this number on an occasion when the amplifier is
not to hand. (e.g. if it is stolen or has been sent away for repair) or the rear is not
easily accessible.
1.3 Warning
To prevent the danger of electric shock or fire hazard do not expose the unit to rain
or moisture. If the unit should come into contact with moisture for any reason, disconnect it from the
mains supply and leave it in a suitable place to dry out.
1.4 Caution
All controls needed for the safe operation of this amplifier are accessible from the
outside of the casing. There are no user serviceable parts inside the unit. Never remove the service covers with the unit connected to the mains supply. In the event of a
failure refer to your Dealer. Unauthorised servicing or tampering with the circuitry may
be dangerous and invalidates your warranty.
1.5 Attention
The RA Series has been designed to be rack-mounted in any standard 19" equipment rack or
(in fixed installations) "stack" mounted on its base. If this amplifier is to be
used in a mobile application it must be properly mounted in a suitable equipment rack
with front and rear support. C Audio will not be responsible for any damage (electronic or mechanical)
sustained due to a failure to rack mount in a mobile application,
or insufficient support in the rack housing. Failure to comply with this may invalidate
the warranty. Please read section four concerning installation which details the correct
procedures for mounting the RA Series.

2. FRONT PANEL CONTROLS
2.1 On/Off
This switch powers up the amplifier. The amplifier is ON when the switch is depressed DOWN. [See 5.1]
2.2 Power Indication
The red power LED is a visual indicator that will light up when the unit is connected
to the mains and switched on.
2.3 Protect
The yellow protect LED is a visual indicator that will light up when there is a fault
condition in the amplifier. When the amplifier is powered up it will light up momentarily. If it should come on during operation switch the amplifier off and leave it to cool
down, then power up again. If it still remains on switch the unit off and consult your
dealer for service advice.
2.4 Bridge
The green bridge LED is a visual indicator that will light up when the amplifier is
being used in bridge mono mode. [see section 5.5]
2.5 Cooling Vent
All high power amplifiers produce considerable heat as a by product of power
output. Keeping an amplifier cool is essential to its performance and long life. The
cooling system of the RA Series employs a fan mounted on the rear of the amplifier
chassis which draws air through the amplifier and exhausts through the vent in the
front panel. It is important to ensure that this vent is never blocked, [see 3.5 and 4.3]
2.6 Level
The two black rotary level potentiometers individually control the input signal to
each of the amplifier's channels. When turned fully clockwise they allow the amplifiers
maximum gain of 32dB to be utilised.