STEREO POWER AMPLIFIER

The Strumento N°4 Signature is a two-channel power amplifier created for audiophiles who demand uncompromising sonic performance and refined design. With bandwidth exceeding 1MHz and output power reaching up to 1000 Watts per channel, it delivers extraordinary speed, control, and precision—even with the most challenging loudspeakers. A distinctive golden plaque on the front signals its exclusivity. The chassis is crafted from ultra-high-grade aluminum casting, then meticulously CNC-machined, hand-polished to a mirror finish, shot-peened, and anodized. This multi-step process results in a flawless metallic surface, combining aesthetic beauty with structural durability. The final touch is precise silk-screening that completes the amplifier’s sophisticated appearance. Inside, the Strumento N°4 Signature reveals fully balanced circuitry and a selection of the finest components available. Mundorf capacitors, Dale resistors, and high-frequency Reed relays ensure low distortion and maximum signal purity. A massive 320,000µF capacitor bank ensures ultra-stable power delivery for dynamic, detailed playback. Custom-designed PCBs with extra gold plating and gold-plated internal audio parts guarantee reliable signal transfer and longevity. At the heart of the Strumento N°4 Signature lies a dual-mono power supply: each channel features two high-current sections supported by four independent stabilized stages—two for the input and two for the Audia Flight current-feedback circuitry. Ultra-fast rectifiers and low-impedance capacitors reduce noise to an absolute minimum. Two 150VA toroidal transformers feed the main audio stages, while a dedicated 15VA transformer powers logic and protection systems. Unlike conventional designs, there are no fuses in the output stage—microprocessor-monitored current sensors replace them to ensure optimal sonic performance. The amplifier’s core gain stage is Audia Flight’s proprietary Class A current-feedback design. It is enclosed in an aluminum shell and embedded in epoxy resin to stabilize temperature and shield it from external interference. The output stage draws power from a custom-built 3000VA transformer, sealed in epoxy resin and protected by twin ferromagnetic shields—ensuring immense power reserves and superior isolation from electrical noise. To preserve sonic integrity, the power transformers are mounted on a separate, mechanically isolated chassis. This setup decouples them from the sensitive audio circuitry, channeling any unwanted vibrations away from critical components. The result: cleaner, more accurate sound—even at extreme volumes. The Strumento N°4 Signature is more than just an amplifier—it’s a masterpiece of engineering, craftsmanship, and musical expression. Its combination of cutting-edge design, artisan-level finishing, and stunning sonic capabilities delivers a listening experience of unmatched realism and emotional impact. Only the Strumento N°8 Signature mono-blocks can exceed its performance, making the N°4 Signature the ideal centerpiece for any reference-level system.

Technical data

Output power per channel Watts RMS @ 8/4/2 Ohm: 300 / 600 / 1000 W
Gain: 29 dB
Input sensitivity: 1.41 Volts RMS
Frequency response (1 W RMS -3 dB): 0,3 Hz ÷ 1 MHz
Slew-Rate (@ 8 Ohm): > 200 V/uS
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 (50-60 Hz): 100, 110 – 115, 220 – 230, 240 V
Stand-by Power consumption: less than 1 W
Nominal Power consumption (no signal): 400 W
Power consumption (260 W RMS @ 8ohm both channels): 1000 W
Dimensions: 450 x 280 x 500 mm (WxHxD)
Weight: 103.5 Kg
Shipping dimensions: 760 x 500 x 630 mm (WxHxD)
Shipping weight: 124 Kg
Available finish: silver or black