Audia Flight Strumento no.4 mk2 Stereo Power Amplifier

The Strumento n°4 mk2 is Audia Flight’s flagship stereo power amplifier, delivering reference-grade performance in a single chassis. Where its mono-block sibling, the Strumento n°8, dedicates an entire enclosure to each channel, the n°4 achieves the same engineering philosophy in stereo form: fully balanced, Class A gain stage, massive power reserves, and zero compromise on parts quality. It is the practical choice for listeners who want Strumento-level performance without the footprint or cost of a mono-block pair.

The mk2 revision refines the original Strumento n°4 with updated circuitry, improved thermal management, and subtle chassis enhancements that reflect Audia Flight’s continued evolution. Every unit is assembled by hand in Audia Flight’s facility in Italy, from the cast aluminum chassis to the epoxy-encased gain stage inside. Each amplifier undergoes an extended burn-in process before it leaves the factory. The result is an amplifier that combines raw authority with musical finesse, equally at ease driving a pair of high-sensitivity monitors at low volume as it is controlling a full-range floorstanding speaker at concert levels.

Paired with the Strumento n°1 evo Preamplifier, the n°4 forms a complete reference-grade amplification chain. For those seeking even more power per channel, the Strumento n°8 Mono Power Amplifier offers the same design philosophy in a dedicated mono-block configuration. And for listeners looking for an entry point into Audia Flight’s power amplifier lineup, the FLS 4 delivers the family sound at a more accessible price.

Key Features

• Stereo architecture with fully independent left and right channel signal paths
• Exclusive Class A gain stage using Audia Flight’s proprietary current feedback topology, encased in epoxy resin
• 250W / 500W / 900W into 8/4/2 ohms (Standard); 300W / 600W / 1000W into 8/4/2 ohms (Signature)
• Dual super high-current power supplies with massive capacitor storage
• 3000VA custom-wound toroidal transformer isolated in its own compartment for clean, distortion-free delivery
• No output-stage fuses: protection handled by microprocessor-controlled current sensors
• Chassis milled from high-grade aluminum, shot-peened, mirror polished, and anodized
• Fully balanced circuitry with high-purity internal copper conductors
• Transformer and power supplies isolated from the signal chassis to eliminate vibration transfer
• Designed, machined, and assembled in Italy with full quality control and burn-in process

What’s Different About the Strumento n°4 Signature Edition?

The Strumento n°4 Signature represents the ultimate expression of this platform. Audia Flight’s engineering team hand-selects upgraded internal components, precision-matched to tighter tolerances and validated through extended listening sessions. The result is a measurable and audible step forward: the Signature delivers 300W into 8 ohms (versus 250W standard), 600W into 4 ohms (versus 500W), and a full 1000W into 2 ohms (versus 900W).

Beyond raw power, the Signature edition features upgraded capacitors, precision-matched resistors, and refinements throughout the signal path that extract greater resolution and dynamic range from the circuit. Externally, it is distinguished by an engraved gold plaque. The Signature shares the same handcrafted chassis and layout as the standard model but pushes every element further. If the Strumento n°4 mk2 is the reference, the Signature is its definitive statement.

Circuitry and Power Delivery

At the heart of the Strumento n°4 mk2 is a completely discrete Class A gain stage, enclosed within a shielded aluminum housing and fully encapsulated in epoxy resin. This construction achieves complete thermal stabilization while blocking electrical interference, preserving signal purity from input to output. The gain stage uses Audia Flight’s proprietary current feedback topology, a design choice that yields exceptionally high slew rates (over 200 V/µs) and wide bandwidth (0.3 Hz to 1 MHz at –3dB).

The output section draws from a 3000VA custom-wound toroidal transformer, mounted in its own isolated compartment. The transformer is encapsulated in epoxy resin and shielded with twin ferromagnetic barriers, a level of isolation that prevents mechanical vibration and magnetic fields from reaching the sensitive signal circuitry. This is the same approach used in the Strumento n°8 mono-blocks.

Capacitor storage is substantial: 280,000µF total, provided by 28 hand-selected 10,000µF low-impedance capacitors. Ultra-fast rectifiers feed the supply rails, and four fully stabilized power stages serve the input and feedback loop independently. In place of output fuses, a microprocessor-controlled current sensor monitors and protects the amplifier without introducing resistance or limiting dynamic headroom. The result is complete authority over current delivery, with zero compromise in speed or transparency.

The Listening Room Difference

The Strumento series is available through only a select number of authorized dealers in the United States. The Listening Room is proud to be among them.

The Listening Room is a third-generation, family-owned hi-fi store built on expertise, honesty, and long-term relationships. We’re a real brick-and-mortar shop located in Chestertown, Maryland. Not a warehouse. Not a dropshipper. When you call, you’re speaking with someone who knows the gear inside and out.

Owner Mike Hoatson is involved in every part of the process. When a Strumento n°4 mk2 is sold, he doesn’t leave delivery to chance. Mike handles it personally. That includes white-glove delivery, full setup, and in-room testing to make sure the system is performing at its best.

We don’t just ship audio equipment. We show up, we install it, and we make sure it’s right.

Technical Specifications