Integrated Streaming Amplifiers vs Separates: Arcam, Cambridge, Innuos

What an Integrated Streaming Amplifier Is – and Why It Matters

An integrated streaming amplifier is a single-box hi-fi component that combines a network streamer, DAC, preamp, and power amplifier, creating an all-in-one audio system that replaces multiple separates, reduces cables and rack space, and still aims for reference-grade sound quality suitable for demanding audiophile listening at home.

Against that definition, Arcam’s SA45, Cambridge Audio’s Evo 300, and Innuos’ STREAM3 answer different questions. The Arcam SA45 is a full-fat DAC amplifier combo with Class G power, Dirac room correction, HDMI eARC, and both moving‑magnet and moving‑coil phono stages, aiming to be a living‑room hub as much as a purist amp. Cambridge’s Evo 300 is a wireless streaming amplifier that packs 300 watts per channel of Class D power into a compact, living‑room‑friendly chassis, targeting listeners with big speakers who still want simplicity. Innuos’ STREAM3, by contrast, is a modular high‑end streaming DAC that focuses on digital source quality first and can then feed any separate amplifier you like. If you want “just‑add‑speakers” convenience, the Arcam and Cambridge are the real rivals; if you already love your power amp, the Innuos is the smarter upgrade.

Design Philosophies: One Box, Three Very Different Takes

All three products question the old belief that serious hi‑fi demands a tower of separates. Innuos explicitly rejects that assumption, aiming to make “serious digital playback more elegant, less intimidating and considerably more adaptable without compromising the aspirations associated with high-end sound.” The STREAM3 platform was built around modularity so one digital chassis can evolve with changing needs instead of locking you into fixed‑function streamers or servers.

Arcam’s SA45 also challenges the multi‑box habit but from an amplifier standpoint. It integrates an ESS Sabre DAC, high‑resolution streaming, built‑in Dirac room correction, Class G amplification, and extensive connectivity so it can anchor both stereo music and TV sound through HDMI eARC. Cambridge’s Evo 300 takes the lifestyle‑friendly route: a sleek aluminium case, a large 7.8‑inch display, interchangeable side panels, and its StreamMagic platform with Spotify Connect, Tidal Connect, Qobuz Connect, AirPlay 2, Google Cast, aptX HD Bluetooth 5.4, and Roon Ready support. All three reduce box count and cable clutter, but Innuos favours modular digital purity, Arcam emphasises a feature‑rich, room‑corrected hub, and Cambridge champions compact high-fidelity amplifier power with mainstream streaming ease.

Power, Topology, and Size: How the Hardware Compares

On paper, the Evo 300 wins the raw‑power race by a wide margin: 300 watts per channel of Class D power into 8 ohms makes it ideal for large rooms and demanding speakers. Arcam’s SA45 counters with a different strength: Class G amplification and a redesigned linear toroidal power supply aimed at low distortion and a quiet noise floor rather than headline wattage. Both are DAC amplifier combos that integrate streaming directly, but Cambridge pushes higher continuous power while Arcam focuses on refinement and room correction. Innuos’ STREAM3 slots in as the specialist digital brain: it becomes a high‑end streaming DAC when fitted with its optional module, yet measuring 420 x 330 x 85 mm and 12.8 kg, it manages to be a compact high-fidelity amplifier partner by high‑end standards, albeit surprisingly heavy for its footprint.

Everyday Use: Strengths, Trade‑offs, and Who Each Suits

If you want an all-in-one audio system that can replace a rack of separates, Cambridge’s Evo 300 feels almost purpose‑built: “For anyone looking for just-add-speakers convenience without feeling like they’re compromising on serious hi-fi performance, the Evo 300 makes a convincing case that you don’t need a rack of separates to get there.” Its compact box is only 7 cm wider than the Evo 150 SE yet doubles the power, making it a compact high-fidelity amplifier that can fill larger spaces. The downside is that in some rooms that 300 W muscle can be surplus to requirements, especially with sensitive speakers.

Arcam’s SA45 is better if you want the amp to be the true system hub. Dirac room correction, HDMI eARC, and dual sub outputs make it easier to integrate with TV and subwoofers while tailoring the sound to your room. It looks premium, though the plastic dials feel “shoogly” and the on‑unit text can be hard to read from a sofa, both shared ergonomic caveats for a device in this class. Innuos’ STREAM3 is for listeners already invested in good amplification who want a modular digital source that can adapt as libraries, formats, and habits evolve, instead of buying multiple fixed‑function streamers over time. All three prove you can now reach high‑end sound without a traditional multi‑box setup, cutting cable complexity while keeping performance ambitions intact.

Buy if / Skip if

• Buy the Arcam SA45 if you want a feature-rich integrated streaming amplifier with Dirac room correction, HDMI eARC, and serious hub capabilities in one chassis.
• Skip the Arcam SA45 if premium-feeling controls and perfectly legible on-unit text matter more to you than built-in room correction and connectivity.
• Buy the Cambridge Evo 300 if you need a wireless streaming amplifier that combines 300 W per channel with tidy design and broad streaming support for a just-add-speakers setup.
• Skip the Cambridge Evo 300 if your speakers are very easy to drive or your room is small enough that its high power feels unnecessary.
• Buy the Innuos STREAM3 if you already own a good amplifier and want a modular streaming DAC platform that can replace multiple digital separates over time.
• Skip the Innuos STREAM3 if you are starting from scratch and prefer a single-box compact high-fidelity amplifier with built-in power instead of adding separate amplification later.