"The Strumento N°1 evo’s gain stage is an exclusive Audia Flight design consisting of an entirely class A current-feedback circuitry. It is fed by four stabilized independent stages per each channel: two for the input stages and two for the output stage. The gain stage is enclosed within an aluminum box and encapsulated by epoxy resin to grant thermal stabilization for all gain stage’s components. The high-current low-noise output stage is made of Class A biased MOSFET audio devices and is able to drive any kind of amplifier."

The Strumento N°1 evo's volume control is a critical aspect of its design, and it aims to address common issues associated with variable impedance volume controls. Here's a summary of its key features:

1. Variable Impedance Control: Traditional volume controls can introduce variable impedance elements as the attenuation changes. This variability can affect the frequency response, slew rate, and internal impedance couplings between different stages of the preamplifier.

2. Constant Impedance Attenuator: Audia Flight has developed a custom attenuator that maintains a constant impedance throughout the entire attenuation range. This attenuator is constructed using discrete components, including low-noise metallic film resistors and relays.

3. Wide Gain Range: The Strumento N°1 evo offers a wide gain range, with the ability to provide a gain as high as 127 dB. This allows for precise adjustment of the volume to suit your preferences.

4. Fine Attenuation Steps: The attenuator provides constant steps of 0.5 dB, ensuring precise control over the volume level.

5. Exceptional Performance: Audia Flight's measurements indicate that the Strumento N°1 evo boasts an extended frequency response (3Hz to 1MHz, -3 dB) and a high slew rate (>250V/µs) across the entire gain range (-90 dB to +10 dB).

6. Silent Operation: The volume control operates silently, without any noise or distortion, as you raise or lower the volume.

This constant impedance attenuator is a notable feature that contributes to the preamplifier's ability to provide accurate and high-performance audio signals for amplification.

Chassis and Components of the Strumento N°1 evo Preamplifier

Chassis Excellence:

• The Strumento N°1 evo boasts a chassis crafted from premium bespoke aluminum cast, ensuring both durability and aesthetics.
• Our meticulous CNC finishing is followed by rigorous hand inspection and "mirror polishing" for a flawless finish.
• Key areas receive further precision hand-finishing, including shot peening and anodization.
• The chassis is adorned with elegant silk-screening for the perfect final touch.

Internals Optimized:

• The heart of the Strumento N°1 evo lies within, powered by four strategically placed toroidal transformers:
  • Two 75VA toroidal audio transformers for primary stages.
  • One 25VA toroidal audio transformer dedicated to control boards.
  • One 15VA toroidal transformer for the logic board.
• All transformers are meticulously enclosed within a ferromagnetic shield and sealed with epoxy resin for protection and stability.

Advanced Power Supply:

• Our preamplifier boasts an exceptionally low-noise main power supply, employing ultra-fast rectifiers and a suite of 40 extra-low impedance capacitors (680µF, 100V) for effective filtering.
• Electrolytic capacitors are fortified with EMI shielding and vibration-damping materials, ensuring minimal physical noise.

Amplification Precision:

• Each amplification channel is equipped with fully balanced circuitry, hosted on individual printed circuit boards.
• We utilize custom printed circuit boards featuring high-grade surface copper.
• The ground and power supplies are anchored by ultra-pure copper bars, preserving signal integrity.
• Signal integrity is maintained as the input signal, post-selection and buffering, meets our precise volume control.

The Strumento N°1 evo exemplifies meticulous craftsmanship and engineering, delivering outstanding audio performance within a visually stunning product.