ARCAM SA45

A flagship built for one room and one purpose

The ARCAM SA45 is the amplifier ARCAM builds when the brief is simply to make the best one. As the flagship of the Radia range, the ARCAM Radia SA45 takes the fully balanced architecture of the A49, the integrated amplifier ARCAM regards as the high point of the company’s amplifier design, and places around that heritage everything a modern music room asks for: high-resolution streaming, digital conversion of reference quality, phono stages for both cartridge types, television connection and room correction. The purpose is a single chassis that removes the reasons for owning separates without removing any of the performance.

The SA45 looks the part. A deep, heavy enclosure, dials that turn with damped precision, and a bonded high-resolution screen wide enough to read from the sofa give the amplifier a presence that photographs cannot quite convey. Designed in Cambridge, the SA45 is intended to remain the centre of a system for a very long time.

Class G, in ARCAM’s fifth generation

Amplification is the competence ARCAM was founded on, and Class G is the form the company has refined over successive generations. The principle is elegant: the amplifier runs in Class A for the opening watts, where music lives most of the time and where the sound is purest, and a second, higher-voltage supply steps in only when a crescendo calls for more. The SA45 represents the fifth generation of that thinking, with components and materials re-examined for this model and a new linear toroidal transformer supplying the whole of the audio circuitry. A separate switching supply exists only for standby, so nothing but the linear supply is at work while music plays.

The result is 180 watts per channel, and a character that belies the number. Quiet passages carry the intimacy of a small Class A amplifier; loud ones arrive with reserves that feel bottomless. Difficult loudspeakers, the kind that expose lesser amplifiers under load, are simply driven, and the sense of grip in the bass is one of the first things a listener notices.

Balanced by design, not by adaptor

Many amplifiers offer an XLR socket and convert the balanced signal to single-ended immediately behind the panel. The SA45 does something rarer at any price: the digital and analogue audio paths are balanced throughout. The new digital platform is built on a multi-layer board with a ground plane spanning the whole of the layout, isolating the audio circuitry from noise and interference. Conversion is by the newest Hyperstream iV DAC from ESS in a balanced arrangement, with jitter elimination ahead of the analogue stages, and the balanced signal then travels to the output stages intact.

For a listener seeking an XLR amplifier, or specifically an amplifier with XLR input for a balanced source, the SA45 offers a dedicated XLR pair alongside three single-ended analogue inputs and delivers balanced pre-amplifier outputs on the way out. Long cable runs to a power amplifier or active loudspeakers lose nothing, the noise floor sits lower, and the space between notes is quieter than an integrated amplifier is usually permitted to be.

Two subwoofers, one coherent low end

Few stereo amplifiers take bass management seriously, and fewer still provide for a pair of subwoofers. The SA45 is a stereo amplifier with subwoofer output twice over, with two subwoofer connections that allow subwoofers to be positioned where the room, rather than the furniture, dictates. Dirac Live Room Correction is included and extends to the subwoofers, so main loudspeakers and subwoofers are measured together and corrected as one system, in time and in level.

The measurement microphone and cable come in the box, and the Dirac Live software walks through the process on a computer: a handful of measurements around the listening seat, a target curve, and a filter exported to the amplifier. What the room used to add, a boom here and a dip there, disappears; what remains is the bass the loudspeakers were always capable of, in the very room where the listening happens.

The screen that changes how streaming feels

An 8.8-inch bonded display gives the SA45 an advantage that is hard to appreciate until lived with. Album artwork, track and artist names and format details are legible from across the room, so the phone can stay in a pocket and the amplifier itself becomes the interface. Presets for favourite stations and playlists are recalled from the front-panel dial, and the remote control carries transport keys so a streaming source is paused, skipped and resumed as easily as a disc.

The platform behind that screen was designed in-house. The SA45 is Roon Ready, streams natively from Qobuz Connect, from Tidal Connect and from Spotify Connect using each service’s own application, and accepts Apple AirPlay and Google Cast from almost any device. Through the ARCAM Radia app come internet radio, podcasts, music on a network drive and files on a USB stick, and high-resolution files play natively with gapless transitions. Software updates arrive over the network in standby, so the platform matures rather than dates.

Records, television, headphones

A flagship integrated amplifier is measured by how many boxes on the rack become redundant. Vinyl is handled by two dedicated phono inputs, one for moving magnet and one for moving coil cartridges, sharing an earth post between them, so that a turntable of any pedigree connects directly with no external stage. The HDMI eARC input allows a television to route sound into the SA45, with the television’s own remote controlling volume and the amplifier waking to the HDMI input automatically, so film and broadcast sound share the same amplification and the same Dirac Live correction as music.

Bluetooth works in both directions: from a phone into the amplifier, and out from the amplifier to wireless headphones for listening after everyone else has retired, with Auracast broadcasting able to reach several sets at once. A choice of four DAC filters lets the balance between transient precision and tonal ease be set to taste, a quiet luxury that most amplifiers at any price do not offer.

Quiet competence in daily use

The refinements continue in the details. The halo lighting around the dials dims to suit the hour, inputs can be renamed and unused ones hidden so the carousel shows only what matters, and the display can be switched off entirely for a late listening session. A Pre Amp Mode turns off the internal power amplifier and turns the SA45 into a balanced streaming pre-amplifier for owners who wish to add a dedicated power amplifier later, which makes the flagship as much a foundation as a destination. Installers will find RS232 and network control and an infra-red input for integration into a wider system.

The ARCAM SA45 streaming amplifier rewards an unhurried audition. Audio Lounge keeps the flagship on demonstration at Wigmore Street and welcomes enquiries about hearing the SA45 with your own loudspeakers, or with a pairing from the showroom chosen to show what the amplifier can do.

About ARCAM

The ARCAM name comes from Amplification and Recording, Cambridge, the company two university engineers established in 1976 to build the A60, an integrated amplifier whose success carried a small workshop into one of the most respected names in British audio. The letter A in ARCAM stands for amplification, and the company has treated that as a first principle for five decades, from the early integrated amplifiers through pioneering outboard digital-to-analogue converters to home cinema receivers that introduced Class G amplification and Dirac Live room correction to a wide audience. Now part of HARMAN, ARCAM designs in Cambridge to this day, and the Radia range gathers amplification, streaming and digital conversion into a single, coherent family. Browse every ARCAM product at Audio Lounge, from the A5+ to the SA45 flagship.