Arcam PA240 Two-Channel Class G Power Amplifier

The PA240 makes a straightforward case: 225 watts per channel of Class G amplification, 50 watts of that in pure Class A, bridgeable to 790 watts in mono. It is Arcam’s most powerful amplifier on a per-channel basis, and it is the right answer when the system demands serious headroom — whether that means driving demanding floorstanders in a two-channel music system, powering left and right in a large cinema room, or providing dedicated amplification for a high-power subwoofer channel. At £2,249 it is not inexpensive, but the engineering it contains justifies the investment.

Where the PA240 Sits in the Arcam Power Amplifier Range

Arcam’s HDA power amplifier range spans three models. The PA410 covers four channels of Class AB amplification at 70W per channel — the multichannel workhorse for home cinema 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 modes.

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. For a home cinema installation, it adds dedicated amplification for the channels that benefit most from headroom — left and right main speakers, or a powered subwoofer driver in bridged configuration. In dual mono mode, the two channels share no common circuitry, which reduces crosstalk and keeps left and right independent throughout.

Sound and Performance

Class G with 50W 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. The 50W figure is generous — it covers real-world listening levels comfortably before the higher-voltage rail engages for dynamic peaks.

When those 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.

In bridged mono mode, the 790W output into 8Ω is available for loudspeakers or driven subwoofer configurations that genuinely benefit from that kind of headroom. Two PA240 units in bridged mono configuration provide 790W to left and right independently — an unusual level of power for a domestic installation, but the right answer for very large rooms or inefficient speakers that other amplifiers simply cannot drive with authority.

Build Quality and Design

The PA240 follows the same design approach as the PA720 and PA410: toroidal transformer power supply, paralleled output transistors, acoustically damped chassis. The two-channel topology means the power supply is not divided across seven or four channels — both channels benefit from the full resource of a supply designed for 225W per side. The physical construction is the same substantial standard as the rest of the HDA range.

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.

Connectivity and System Matching

In an AV cinema system, the PA240 connects to the pre-outputs of the AV41 processor via balanced XLR for the channels it is responsible for. Paired with a PA720 handling the seven main channels, the PA240 can take on a specific pair — most usefully the left and right main speakers in a large room where 100W from the PA720 is not enough headroom.

For a two-channel music system, the PA240 acts as a standalone power amplifier paired with any preamplifier or integrated amplifier that has a pre-output. It is equally at home in a stereo context as it is in a multichannel installation, which makes it a flexible long-term investment if your system evolves over time. Speaker matching is wide: at 225W into 8Ω and 790W bridged, virtually any domestic loudspeaker can be driven with substantial headroom.

Technical Specifications

Who Is the PA240 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 makes for one or two channels, the PA240 is the answer.

Buying from Martin’s Hi-Fi

Martin’s Hi-Fi has been in Norwich since 1968, and the Arcam range has been part of what we do for years. We are still family-run — Ted Martin’s daughter Elizabeth runs the business today — and we stock only brands we have heard properly and stand behind.

The PA240 is available to hear in our Norwich showroom; call ahead and we will have it set up with a system that makes sense for your budget. When you get in touch, you will be speaking to Dave or Chris — both experienced hi-fi specialists who can talk you through whether the PA240, PA720, or PA410 is the right fit for your room and your system.

Reach them at dave@martinshifi.co.uk, chris@martinshifi.co.uk, info@martinshifi.co.uk, call on 01603 627010, or WhatsApp Dave or Chris directly on 07554 687137 for a quick answer after your purchase. You can read more about who we are and how we work on our Why Martin’s page. We are at 85–91 Ber Street, Norwich, NR1 3EY, open six days a week.

Contact: info@martinshifi.co.uk | 01603 627010 | WhatsApp: 07554 687137 | 85–91 Ber Street, Norwich, NR1 3EY