Arcam PA410 Four-Channel Power Amplifier

The Arcam PA410 is a four-channel Class AB power amplifier in a dedicated chassis, built for the channels that most AV receivers handle poorly under sustained load. At 70 watts per channel with all four channels driven, 0.003% THD at 80% power, and a signal-to-noise ratio of 105dB, it adds genuine amplification quality to any AV system that needs to expand beyond what the receiver handles on its own.

Where the PA410 Sits in the Arcam Range

Arcam's power amplifier range covers three models. The PA240 is a two-channel Class G design at 225W per channel with 50W of Class A operation — substantial power for a stereo pair of demanding speakers or two cinema channels. The PA410 sits in the middle: four channels of Class AB amplification at a practical power level for the surround and height channels that most home cinema systems need to cover. Above it, the PA720 delivers seven channels of Class G amplification at 100W, designed primarily as the main channel solution in an AV41-based system.

The PA410's role in a typical system is to handle the additional channels that the main amplifier does not cover. In a Dolby Atmos 7.1.4 configuration paired with the AV41, the PA720 handles the seven main channels and the PA410 takes the four height channels. This division of labour is a cleaner engineering solution than asking a single chassis to drive eleven channels simultaneously.

Class AB Amplification

Class AB amplification in the PA410 means there is always a portion of each output transistor's operation in Class A — the region where the device is conducting continuously rather than switching. This eliminates the crossover distortion that pure Class B designs are susceptible to, and it is the reason Class AB remains the standard for quality audio amplification. The 0.003% THD figure at 80% power into 8Ω at 1kHz is the performance consequence: a distortion level inaudible in any practical listening context.

The paralleled transistor output stages and acoustically damped chassis both address the same goal from different directions: reducing noise that is not in the signal. With 700W maximum consumption for four channels, the PA410 is not under-specified for its power output — the headroom in the power supply means the amplifier does not compress under dynamic peaks.

Build Quality and Design

The PA410 matches the PA720 and PA240 in physical approach: toroidal transformer, substantial chassis, and a footprint designed to stack neatly in a rack alongside an Arcam processor or receiver. At 433 × 325 × 105mm and 10kg, it occupies a single standard rack unit height. Both balanced XLR and unbalanced RCA inputs are fitted and switchable. RS232 and Ethernet control ports support professional installation and integration with third-party control systems.

Technical Specifications

Who Is It For?

The PA410 suits anyone expanding a home cinema system beyond the channels their receiver amplifies directly — most commonly for Dolby Atmos height speakers in a 5.1.4 or 7.1.4 configuration. It is also a straightforward upgrade path for anyone running an AVR5 who wants to move dedicated amplification for surround channels into a separate chassis. If you need seven channels from a single unit, the PA720 is the answer. If you need two channels at higher power, the PA240 is worth considering.

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 talk you through whether the PA410, PA720, or PA240 is the right fit for your room and system, and have it set up in our Norwich showroom for you to hear.

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.