Form and function

The S17 Pro Evo has a completely unusual shape, at least in the world of Eastern manufacturing, and especially in its price range. It is a block of aluminium milled from a single piece that looks like a wave: soft, sinuous, elegant. Its lines unmistakably reflect its sound character, that of a Class A amplifier. It does not harden or distort, but accompanies and caresses, interpreting the signal with the same softness and elegance as its shape. Just as a true high-end product would do.

The front panel features a colour display that uses a two-tone colour scheme to indicate output level and operating temperature, providing an immediate overview of the amplifier's operating status. The single knob on the right is multifunctional: it can be used to control power, gain and, of course, volume, making it quick and intuitive to use. The aluminium remote control completes the experience, allowing convenient management even from a distance. The S17 Pro EVO is not only a headphone amplifier, but also a preamplifier with a completely discrete approach, without operational amplifiers and with a balanced architecture. It belongs to Aune's new generation of Class A amplifiers and is based on a Twin JFET structure, a technical choice that aims to combine the tonal qualities typical of JFETs, in many ways similar to valves, with the stability and precision of solid-state circuits.

The system uses selected pairs with the same operating temperature and power characteristics, thus ensuring symmetrical, stable and consistent performance over time: a fundamental element for quality and reliability. The final stage adopts a parallel architecture that uses two pairs of transistors per channel, for a total of sixteen output transistors, with a maximum power of 7.5 W. This configuration is designed to achieve very high driving capacity, so that no headphones are a problem, not even the most difficult high-impedance or demanding planar ones. There are two levels available, corresponding to two distinct operating modes: low and high current. The first is designed for easy loads, the second for maximum dynamics and driving authority.

The latter involves a gradual increase in operating temperature, which is constantly monitored and controlled by the system via a complex three-dimensional cooling structure. The heat sinks on the transistors, the lower heat plate, and the chassis work as a single integrated system, conveying and dissipating heat through the rear openings and ensuring efficient dissipation and constant operating stability even during long listening sessions at high power. A thermal protection system automatically intervenes when the temperature reaches critical thresholds, returning the amplifier to a more conservative operating mode without compromising sound quality. Volume control is handled by an electronic R2R system based on JRC chips, configured in a balanced structure that allows for extremely precise and consistent adjustments between channels. This solution avoids the typical problems of traditional potentiometers, ensuring perfect balance even at the lowest listening levels, which is essential for those who use high-sensitivity headphones or IEMs. A large 50-watt low-ripple toroidal transformer powers the entire device. It has separate windings for the digital and analog sections to avoid interference and signal contamination. Filtering is handled by a bank of capacitors totaling 19,200 µF, ensuring a stable power reserve and immediate dynamic response even in the most demanding musical passages.

From a functional point of view, the S17 Pro EVO offers a wide range of connections that make it extremely versatile: three headphone outputs (6.3 mm, 4.4 mm and balanced 4-pole XLR), two sets of preamplified outputs (RCA and XLR) with the same number of line inputs, for maximum integration with any usage scenario, from desktop systems to Hi-Fi systems. The S17 Pro EVO is available in black or silver.

Who is Aune Audio?

AUNE is an Eastern manufacturer that has gradually established itself in the hi-fi and personal audio scene thanks to a strongly research-oriented approach. The brand was founded in the mid-2000s, initially focusing on the development of digital circuits and D/A converters, before expanding its catalogue to include solid-state and hybrid amplifiers, balanced solutions, DACs with increasingly sophisticated architectures and, later, magnetoplanar headphones.

Tecnical specification

Inputs: 1x single-ended stereo RCA, 1x balanced stereo XLR
Outputs: 1x 6.35 mm, 1x balanced 4.4 mm, 1x 4-pin XLR, 1x RCA, 1x balanced XLR
RCA/XLR input impedance: 10 kΩ
RCA/XLR output impedance: 200Ω/100Ω
Frequency response: 20Hz~80kHz (±0.05dB)
THD+N: < 0.0003% @ 1kHz
Signal-to-noise ratio: > 115dB @ 600Hz
Crosstalk: -105dB @ 1kHz, 600Hz
High/low gain output power: 738mW 32Ω RCA-2.88W 32ΩXLR/2W 32ΩRCA-7.5W 32Ω XLR
Dimensions: 288 x 211 x 63 mm
Package contents: 1x Aune S17 Pro EVO, 1x remote control, 1x power cable, 1x 6.35 mm to 3.5 mm jack adapter