Soulnote A-0 ver.2 – Integrated Amplifier without Negative Feedback

The Japanese audio manufacturer Soulnote has released the second version of its A-0 integrated amplifier, which delivers just 10 watts per channel, though in this case the modest power figures are part of a deliberate concept. The designers focused not on a substantial power reserve, but on precision, control, and musical expressiveness. What we have here is an amplifier with an extremely minimalist philosophy, built on a fully discrete circuit and operating without negative feedback.

At the core of the Soulnote A-0 ver.2 lies an unconventional approach to amplification: the minimum necessary power is used as a means of achieving higher sound quality. The manufacturer emphasizes that 2 x 10 watts is entirely sufficient for realistic listening in a living room, especially when paired with sensitive loudspeakers. This principle allows the design to concentrate on tonal accuracy, the rendering of rhythmic structure, and the preservation of the finest nuances of a recording.

The amplifier’s construction is built around the idea of the shortest and most direct possible signal path. The input selector and volume control are directly linked to the power amplification stage, while the number of components in the circuit has been reduced to a minimum. Such an architecture is intended to minimize any losses along the signal path and to ensure a more open, immediate, and structured sound.

One of the key features of the Soulnote A-0 ver.2 is its fully discrete circuitry without the use of negative feedback. In traditional amplifiers, feedback is employed to correct deviations that arise, but Soulnote prefers a different path – the most direct possible signal transmission without additional intervention. According to the company, this approach helps preserve the natural quality of microdynamics, improves the reproduction of fine detail, and makes the musical presentation more lively and unconstrained.

The amplifier’s output stage also follows this philosophy. It is based on a push-pull configuration using high-speed TO-220 transistors with low collector-base capacitance. Thanks to their fast response to signal changes, this design contributes to accurate impulse reproduction, careful handling of dynamic transitions, and better articulation of subtle sonic details.

With an output power of 2 x 10 watts, the model is intended primarily for use with high-sensitivity loudspeaker systems. In a standard living room, this is more than enough to achieve a comfortable and natural listening level, as well as a precise and convincing soundstage. At the same time, the amplifier operates in its optimal range most of the time, without being burdened by the need to manage excessive power reserves.

The manufacturer places special emphasis on the Soulnote A-0 ver.2’s ability to reproduce the finest elements of a recording with care and precision. Quiet passages, spatial layers, decay nuances, and barely perceptible dynamic shifts remain clear and intelligible. These same advantages also extend to the built-in headphone amplifier, which likewise benefits from the strengths of the stable output stage.

In the second version of the model, the bias circuit has been revised. This refers to the operating state of the output stage in the absence of a musical signal. A more stable bias setting helps reduce background noise, making the sound cleaner and allowing faint and delicate details to become more noticeable.

Despite its audiophile focus, the device is quite versatile. The Soulnote A-0 ver.2 can serve not only as an integrated amplifier, but also as a preamplifier. For this purpose, it is equipped with a pre-out available on both RCA and XLR connectors. In addition, the user can choose between two gain levels for more precise matching with external power amplifiers, active loudspeakers, or a subwoofer.

The Soulnote A-0 ver.2 integrated amplifier will be available in two finish options – black and silver. The recommended retail price of the new model on the European market is 2,700 euros.