Arcam PA240 Two-Channel Power Amplifier

The Arcam PA240 is a two-channel Class G power amplifier delivering 225 watts per channel, with 50 watts of pure Class A operation and the option to bridge to 790 watts in mono. It sits at the top of Arcam's HDA power amplifier range on a per-channel basis, and it is the right answer when the system demands serious headroom — driving demanding floorstanders in a two-channel music system, powering left and right channels in a large cinema room, or providing dedicated amplification for a subwoofer in bridged configuration.

Where the PA240 Sits in the Arcam Range

Arcam's HDA power amplifier range covers three models. The PA410 handles four channels of Class AB amplification at 70W per channel — the multichannel workhorse for height and surround duties. The PA720 delivers seven channels of Class G amplification at 100W, designed as the main channel solution in an AV41-based system. The PA240 is different in character from both: two channels, substantially higher power per channel, and the flexibility to operate in stereo, dual mono, or bridged mono.

The PA240's two-channel topology makes it versatile across contexts. For a two-channel music system it is a serious power amplifier for demanding speakers. Paired with the SA45 via balanced XLR, it bi-amplifies the system cleanly. For a home cinema installation it adds dedicated amplification for the channels that benefit most from headroom — left and right mains, or a powered subwoofer in bridged configuration. In dual mono mode the two channels share no common circuitry, which reduces crosstalk and keeps left and right independent throughout.

Class G Amplification

Class G with 50 watts of Class A operation means the PA240 spends the majority of its working life in pure Class A. Most music and cinema listening at reasonable levels stays within the Class A bias region, where the output transistors are always conducting and there is no switching transition in the signal path. When dynamic peaks arrive, Class G handles them cleanly — the architecture switches to the higher supply voltage for the duration of the transient, then returns to the efficient lower rail. There is no audible transition because the switching happens at the supply level rather than in the signal path. The result is an amplifier with the low-level refinement of a Class A design and the dynamic capability of a much larger Class AB unit.

Build Quality and Design

The PA240 uses a toroidal transformer power supply, paralleled output transistors and an acoustically damped chassis. The two-channel topology means the power supply is not divided across multiple channels — both channels benefit from the full resource of a supply designed for 225 watts per side. Balanced XLR and unbalanced RCA inputs are both fitted and switchable. Ethernet and RS232 control ports support professional installation and integration with control platforms including Elan, RTI and URC. Dual mono and bridged mono configurations are set via the rear panel.

Technical Specifications

Who Is It For?

The PA240 suits two distinct listeners: the two-channel enthusiast with demanding speakers that need genuine power and Class A refinement; and the home cinema builder who wants to give specific channels — main left and right, or a subwoofer driver — dedicated high-power amplification separate from the multichannel chassis. If you need four or seven channels in one box, the PA410 or PA720 are the more practical choices. If you need the highest power level Arcam make for one or two channels, the PA240 is the answer.

Buying from Martins Hi-Fi

Martins Hi-Fi has been in Norwich since 1968. Elizabeth Gould runs the business today, and we stock only brands we have heard properly and stand behind. Arcam have been a core part of our range for many years — Dave and Chris can advise on partnering speakers and sources, and talk you through whether the PA240, PA720 or PA410 is the right fit for your room and system. You can hear the PA240 in our Norwich showroom; call ahead and we will have it set up with a system that makes sense for your brief.

Contact us at info@martinshifi.co.uk, call 01603 627010, or WhatsApp on 07554 687137. You can read more about how we work on our Why Martins Hi-Fi page. We are at 85–91 Ber Street, Norwich, NR1 3EY.