Arcam PA240 Power Amplifier

Arcam PA240 power amplifier is a two-channel model for stereo systems requiring a separate power stage. It uses Class G amplification and supports three operating configurations: stereo, dual mono, and bridged mode.

Construction and amplification design

The power supply uses a toroidal transformer, while the chassis is acoustically damped. Parallel-connected transistors are used in the output stages.

The amplifier can operate in Class A up to 50 W, with the Class G circuit providing additional power when required. This combines a Class A operating range with greater power reserves in a single unit.

Choosing between RCA and XLR inputs

You can select either the RCA input or the balanced XLR input. Use RCA with equipment that has an unbalanced line-level output. Choose XLR when the connected preamplifier or processor also provides a balanced output.

An XLR connection maintains a balanced signal path between the components. The input selector must match the cable being used, so this should be considered before the equipment is placed in its final position.

Control and system integration

The Ethernet and RS232 connections are provided for amplifier control. They can be used when integrating the PA240 with a compatible automation controller. The Ethernet port is a control connection, not a music playback input.

RS232 is useful in systems where control commands are transmitted over a wired connection. These control ports do not replace the RCA or XLR audio inputs. An analogue connection must still be selected for the audio signal.

Three operating modes

In stereo mode, both amplification channels operate independently. This is the conventional choice for driving the left and right speakers in a stereo system. Dual mono mode requires a suitable system connection arrangement, so consult the manufacturer’s instructions before connecting the equipment.

Bridged mode combines the amplifier’s power capabilities for one channel. In this configuration, the specified output is 790 W into an 8-ohm load. Select the mode before connecting the speaker because the required terminals differ from those used for stereo operation.

Understanding the quoted power output

Stereo output is rated at 2 × 225 W into 8 ohms. Bridged operation provides one 790 W channel into 8 ohms. Both figures are measured across the 20 Hz-20 kHz frequency range at 0.2% total harmonic distortion.

These conditions allow meaningful comparison only with power figures defined in the same level of detail. A rating measured at another frequency, load, or distortion level is not directly equivalent.

Placement and preparation

Place the amplifier on a stable surface and leave enough space around the chassis for heat to escape. Allow sufficient room behind the rear panel for signal and control cables. The acoustically damped chassis does not remove the need for a suitable, stable support.

Before switching on the system, select the required operating mode and input type. Connect the signal source, amplifier, and speakers first. Then confirm that the mode and input switches correspond to the chosen connection arrangement.

Technical specifications

Parameter	Value
Model	Arcam PA240
Type	Two-channel power amplifier
Amplification class	Class G with 50 W of Class A operation
Stereo output power	2 × 225 W into 8 ohms, 20 Hz-20 kHz, 0.2% THD
Bridged-mode power	1 × 790 W into 8 ohms, 20 Hz-20 kHz, 0.2% THD
Operating modes	Stereo, dual mono, bridged
Analogue inputs	Switchable RCA and balanced XLR
Control	Ethernet and RS232
Power transformer	Toroidal
Chassis	Acoustically damped
Output stages	Parallel-connected transistors

FAQ

Is this an integrated amplifier?

No. It is a separate power amplifier and requires a preamplifier or processor with a suitable line-level output. Source selection and volume are controlled by the component connected before the power amplifier.

When should I choose RCA or XLR?

Choose RCA for an unbalanced source output. Use XLR when both connected components support a balanced signal. The selected cable must correspond to the position of the amplifier’s input selector.

What does bridged mode change?

Both amplification channels are used to power one 8-ohm channel, for which the specified output is 790 W. Select bridged mode before connecting the speaker and follow the terminal markings on the rear panel.

Can the Ethernet connection carry music?

No. The Ethernet connection is intended for device control. The music signal is carried through the selected RCA or balanced XLR input.

What is RS232 control used for?

RS232 allows the amplifier to be included in a wired automation system. It is useful when several audio components are managed through a central control system.

How much space should I leave around the amplifier?

Leave open space for heat to escape and for cables to be connected. Do not place the unit on an unstable surface or inside a cramped, completely enclosed compartment.