Fully Discrete · Class-A · Fully Balanced
The New Generation of Headphone Amplifier
Twin JFET · Class-A · Adjustable Current · R2R Volume
The Aune S17 Pro EVO is a new-generation, fully discrete Class-A headphone amplifier built for uncompromising performance. It features a twin-JFET input stage, R2R volume control, selectable Class-A bias current (50 mA / 100 mA per transistor), output power up to 7.5 W, three headphone outputs, and two preamp outputs. The result is a powerful, richly musical amplifier designed for reference-level listening.
Twin JFET Input Stage
Tube-Like Musicality
JFETs offer high input impedance and a rich, smooth, tube-like sound signature. The S17 Pro EVO uses matched twin JFETs, ensuring identical thermal behavior, consistent performance, and stable midpoint voltage—making them ideal input devices for a high-end headphone amplifier.
Dual Output Transistors per Channel
High Power, Total Control
The output stage uses two pairs of transistors in parallel per channel, for a total of 16 output transistors. With a maximum output of 7.5 W, the S17 Pro EVO effortlessly drives everything from sensitive IEMs to the most demanding planar and high-impedance headphones.
Adjustable Class-A Bias Current
Two Operating Modes
Two Class-A bias levels are available: 50 mA / 100 mA per transistor. With dual transistor pairs per channel, the quiescent current reaches 100 mA / 200 mA per channel, delivering the signature warm, smooth, and organic sound of Class-A amplification.
Pure Class-A Amplification
In a Class-A amplifier, output transistors remain conducting at all times, operating in their most linear region. This results in extremely low distortion, exceptional detail, and a lush, natural presentation with outstanding musical realism.
R2R Electronic Volume Control
Precision and Balance
The S17 Pro EVO employs a JRC R2R electronic volume chip with dedicated op-amps to form a four-channel fully balanced R2R volume control, delivering precise level adjustment, excellent channel matching, wide soundstage, and pinpoint imaging.
Smart Display Interface
Current & Temperature at a Glance
The redesigned display uses color-coding to clearly indicate bias current level and operating temperature.
(In 100 mA mode, gradual temperature rise is normal. Thermal protection automatically switches to 50 mA at 69 °C.)
Dual Gain Levels
Optimized for Headphones & IEMs
Low gain maximizes Class-A linearity for sensitive IEMs, while high gain delivers up to 7.5 W, providing ample headroom for power-hungry headphones.
Advanced Thermal Management
Stable Class-A Operation
Aune’s multi-layer cooling architecture integrates transistor heatsinks, a bottom heat plate, and the aluminum chassis into a unified cooling system, ensuring long-term thermal stability for continuous Class-A operation.
50 W Toroidal Transformer + 19,200 µF Capacitor Bank
Power with Musical Weight
A low-ripple 50 W toroidal transformer, dual power-supply architecture, and a 19,200 µF capacitor array ensure clean, interference-free power delivery with exceptional dynamics and tonal richness.
Multi-Function Knob & Aluminum Remote
Intuitive Control
A single multi-function front knob controls volume, gain, and bias current. The included all-aluminum remote adds convenience without compromising design or build quality.
Comprehensive Connectivity
Preamp Functionality Included
- 3 headphone outputs
- 2 preamp outputs
- 2 line inputs
Designed to integrate seamlessly into desktop or full Hi-Fi systems.
Elegant Industrial Design
The Beauty of the Arc
The signature arc-shaped design is clean, minimalist, and timeless—crafted to complement both modern and classic audio setups.
Carefully Selected Hi-Fi Components
Only premium components are used, including high-grade audio capacitors, communication-grade PCBs, and organic thin-film capacitors—every choice made purely for sound quality.
High-Performance Specifications
- Output noise (high gain): 4 µV
- THD+N: 0.00016%
A technically robust foundation for truly reference-class sound.
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