Audia Flight - Strumento n°4 mk2 - Power Amplifier

The Strumento N°4 mk2 Stereo Power Amplifier represents the pinnacle of two-channel power amplification, offering remarkable response speeds (with a bandwidth exceeding 1MHz), substantial output power (up to 900 Watts), and exceptional speaker control capabilities.

In crafting the mk2 version, we drew from our expertise in designing the Strumento N° 8 Mono-block Power Amplifier and employed our keen ears to refine the original Strumento N°4 circuit. These refinements, which include subtle yet crucial changes to resistor and capacitor values, have brought us closer to our goal of achieving sonic perfection. This process mirrors the craftsmanship of a luthier who uses years of experience and a discerning ear to find the perfect tonal character and emotional response in their instruments.

The chassis of the Strumento N°4 mk2 begins as an ultra-high-grade bespoke aluminum cast. After CNC finishing, each component undergoes meticulous hand inspection and "mirror polishing." Critical areas receive additional hand finishing, while shot peening and anodization complete the exquisite metalwork. The finishing touch is an elegant silk-screening process.

Within the beautiful casework of the Strumento N°4 mk2, meticulous Italian craftsmanship shines. You'll discover fully balanced circuitry, carefully selected ultra-high-grade components, and a massive power supply built with extra-low impedance. Ultra-high-grade capacitors (with 280,000µF on the main power supply alone), custom printed boards featuring extra-high-grade surface copper, and ultra-pure copper bars in the output stages exemplify our commitment to excellence.

But the Strumento N°4 mk2 Stereo Power Amplifier doesn't stop there. Its power supply consists of two super-high-current supplies per channel and four independent stabilized stages for each channel. Two 150VA toroidal audio transformers power the main stages, while a 15VA toroidal transformer handles logic control and protection. The main power supply employs 28 10,000µF 40V extra-low impedance capacitors, omitting fuses in favor of a current sensor read by a microprocessor to maintain sound quality.

The amplifier's gain stage is an exclusive Audia Flight design, featuring a fully class A current-feedback circuitry. To shield this crucial amplification component from interference and ensure thermal stability for its discrete elements, the gain stage resides in an aluminum enclosure encapsulated in epoxy resin. The output stage, powered by a massive 3000VA custom-made audio transformer, is similarly sealed within two ferromagnetic shields. Ultra-fast rectifiers are employed on the main power supply for the output stage, eliminating the need for fuses.

Attention to detail extends to mechanical aspects. When the amplifier rests on a shelf, the power transformers, located on an independent chassis, are physically decoupled from the audio circuit chassis, effectively grounding any extraneous vibrations from the transformers.

The Strumento N°4 mk2 Stereo Power Amplifier is a masterpiece, combining aesthetics and electronics in a single chassis. Only a pair of its siblings, the Strumento N° 8 Mono-block Power Amplifier, can surpass its excellence.

Enhance Your Sound Experience with the Strumento N°4 mk2 Stereo Power Amplifier, Where Artistry Meets Audiophilia.



Specifications	Values
Output power per channel Watts RMS @ 8/4/2 Ohm	250/500/900W
Gain	29 dB
Input sensitivity	1.41 Volts RMS
Frequency response (1W RMS -3dB)	0.3 Hz ÷ 1 MHz
Slew-Rate (@ 8 Ohm)	200 V/µS
THD	0.05 %
S/N Ratio	110 dB
Input impedance	Unbalanced: 7.5 kOhm, Balanced: 7.5 kOhm
Damping factor (@ 8 Ohm)	1000
Main voltage AC (50-60Hz)	240 V
Stand-by Power consumption	Less than 1W
Nominal Power consumption (no signal)	400W
Power consumption (260W RMS @ 8ohm both channels driven)	1000W
Dimensions and weight	450x280x500mm (W x H x D) – 95kg
Shipping dimensions and weight	580x410x700mm (W x H x D) – 125kg