Arcam SA45 Streaming Integrated Amplifier

There is a point in Arcam's range where the engineering stops being about hitting a price bracket and starts about doing things properly. The SA45 is that point. Designed in Cambridge, it traces a direct line back to the A49 — Arcam's best integrated amplifier — and brings that engineering heritage into a single unit that streams, amplifies, and manages a room, without compromise in any of those roles.

A New Platform, Built for the Whole Signal Path

The SA45 is built on an entirely new 6-layer digital audio and streaming platform. The board incorporates a ground plane running through its entirety — a deliberate engineering decision to isolate the sensitive audio components from noise and interference. This matters more than it sounds: digital streaming and high-gain analogue amplification are not natural neighbours on a circuit board, and most products at this level make concessions. Arcam have not.

At the heart of the digital section sits the ESS Hyperstream IV DAC topology, run in a balanced configuration with advanced jitter elimination. The Hyperstream IV is the current flagship DAC architecture from ESS, and Arcam are using it in a fully balanced implementation — a signal path decision that pays dividends in noise floor and dynamic clarity. The result is a DAC stage that supports up to 32-bit/384kHz streaming, with gapless playback across FLAC, WAV, AAC, ALAC, AIFF, DSD up to DSD256, MP3, OGG, and WMA.

Class G Amplification — Fifth Generation

The amplifier section is Arcam's fifth-generation Class G design. Class G operates more efficiently than Class AB by using multiple supply rails, switching to higher voltage only when the signal demands it. The result is lower operating temperatures, lower noise, and better dynamics — particularly on transients where the music suddenly asks for more power. Two channels driven, 20Hz–20kHz into 8Ω: 180W. Into 4Ω at 1kHz: 300W. Harmonic distortion at 80% power into 8Ω: 0.002%. These are not modest numbers. This is an amplifier that will drive difficult loads without strain.

Power comes from a new linear toroidal transformer — a considered choice. Toroidal transformers generate less electromagnetic interference than conventional EI-core designs, and Arcam have used it to supply the entire internal operation, further protecting the audio circuit from noise.

Analogue Connections, Including Phono

The SA45 carries three RCA analogue input pairs and one XLR balanced input. Both MM and MC phono stages are included — a meaningful inclusion at any price, and a confirmation that Arcam expect this amplifier to sit at the centre of a considered, permanent system rather than a convenience setup. Frequency response across the analogue section is 20Hz–20kHz ±0.2dB, with a signal-to-noise ratio of 106dB (A-weighted, ref. 50W, 1V input).

Digital inputs cover two coaxial (RCA) and two optical (Toslink), plus HDMI eARC — useful for integrating a television without degrading the signal chain. Digital inputs support up to 24-bit/192kHz.

Streaming and Wireless

Wi-Fi is dual-band, covering IEEE 802.11 a/b/g/n/ac/ax across 2.4GHz and 5GHz — current-generation Wi-Fi 6 specification. Setup is handled through the ARCAM Radia App, which also manages presets, internet radio, and podcasts. Once connected, the SA45 supports Apple AirPlay, Google Cast, Spotify Connect, Tidal Connect, Qobuz Connect, and Roon Ready. UPnP and USB media playback via USB-A mass storage are also supported.

Bluetooth is version 5.4, with Snapdragon Sound, AAC, LE Audio, and Auracast. Auracast is Bluetooth's broadcast audio standard — it allows the SA45 to share audio to compatible Bluetooth headphones or hearing devices without pairing. Worth noting for households where one listener wants to sit closer to the music than the rest of the room.

Display and Room Correction

The front panel carries a bonded 8.8-inch high-resolution display, showing album artwork and metadata. Dual subwoofer outputs are provided, and Dirac Live Room Correction is built in — supplied with a measurement microphone and 5m USB cable in the box. Dirac Live is one of the most respected room correction systems available; its inclusion here, fully licensed, is not a token feature.

Technical Specifications

Who Is It For?

The SA45 is for someone who wants a single unit at the heart of a serious system — not a convenience compromise, but a deliberate architectural choice. If you have a record collection, a streaming subscription, a television, and possibly a subwoofer, this amplifier addresses all of them from one chassis without asking you to sacrifice the quality of any input. It is particularly well suited to speakers with demanding impedance curves; the headroom into 4Ω is substantial.

It is not the right choice if you prefer separate boxes for their own sake, or if you are building a system where the amplifier will eventually be upgraded independently of the source. For those listeners, a dedicated streamer such as the Arcam Radia ST5 paired with a dedicated amplifier may make more sense. But for the listener who wants the best single-box solution Arcam make, the SA45 is it. If you'd like to explore a CD source alongside streaming, the Arcam Radia CD5 pairs naturally with it.

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.

The SA45 is available to hear in our Norwich showroom — we would encourage you to bring your own music and take the time to listen properly. You can pair it with speakers from our demonstration room to hear what it does with a load it can genuinely drive.

When you get in touch, you'll be speaking with Dave, Chris and Tim — experienced specialists who can advise on this product and your whole system.

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.