1. Introduction
The Aune S17 Pro EVO is a high-performance headphone amplifier and pre-amplifier designed for discerning audio enthusiasts. Featuring a pure Class-A, fully-discrete, and fully-balanced circuit design, it delivers exceptional sound quality and powerful output for a wide range of headphones and In-Ear Monitors (IEMs). This manual provides essential information for setting up, operating, and maintaining your S17 Pro EVO to ensure optimal performance and longevity.
Figure 1: Aune S17 Pro EVO Headphone Amplifier (Black)
2. Safety Instructions
- Voltage Warning: This product must be used at 110V voltage. Excessive voltage will damage the product and void the warranty.
- Do not expose the device to rain, moisture, or extreme temperatures.
- Do not open the casing. Refer all servicing to qualified personnel.
- Ensure proper ventilation around the device to prevent overheating.
- Keep out of reach of children.
3. Package Contents
Please check the package contents upon unboxing. If any items are missing or damaged, contact your retailer.
- Aune S17 Pro EVO Headphone Amplifier Unit
- Power Cable
- User Manual
- Remote Control (All-Aluminum)
4. Product Overview
4.1. Front Panel
Figure 2: Front Panel Layout
- Headphone Outputs: 6.35mm, 4.4mm Balanced, 4-pin XLR Balanced.
- Display: 4-inch screen showing volume, input, gain, and quiescent current.
- Multi-Function Knob: Controls volume, input selection, and other settings.
4.2. Rear Panel
Figure 3: Rear Panel Connections (Example, actual may vary slightly)
- Audio Inputs: XLR Balanced, RCA Unbalanced.
- Preamp Outputs: XLR Balanced, RCA Unbalanced.
- Power Input: AC 110V.
4.3. Key Features
- Twin JFET Design: High input impedance and rich sound, with stable mid-point voltage.
- Pure Class-A Amplification: Mellow, warm, and smooth sound.
- Dual Gain Levels: Optimized for both sensitive IEMs and power-hungry headphones (up to 7.5W output).
- R2R Electronic Volume Chip: High control precision, excellent channel balance, wide soundstage, and accurate positioning.
- Fully-Discrete, Fully-Balanced Circuitry: Ensures high fidelity and minimal interference.
- Robust Power Supply: 50W low-ripple toroidal transformer and 19200µF capacitor array for powerful and rich sound.
- Advanced Cooling System: 3-dimensional cooler structure for stable Class-A operation and overheat protection.
5. Setup
- Placement: Place the S17 Pro EVO on a stable, flat surface with adequate ventilation. Avoid placing it near heat sources or in direct sunlight.
- Power Connection: Connect the provided power cable to the AC 110V input on the rear panel and then to a suitable power outlet.
- Source Connection: Connect your audio source (e.g., DAC, CD player) to the S17 Pro EVO using either the XLR Balanced or RCA Unbalanced input ports on the rear panel.
- Output Connection (Headphones): Plug your headphones into one of the front panel outputs (6.35mm, 4.4mm Balanced, or 4-pin XLR Balanced).
- Output Connection (Preamp - Optional): If using the S17 Pro EVO as a pre-amplifier, connect its XLR Balanced or RCA Unbalanced preamp outputs to your power amplifier or active speakers.
- Power On: Flip the power switch on the rear panel to the 'ON' position. The front display will illuminate.
6. Operating Instructions
6.1. Volume Control
- Rotate the multi-function knob on the front panel clockwise to increase volume and counter-clockwise to decrease volume.
- The volume level is displayed on the 4-inch screen.
6.2. Input Selection
- Press the multi-function knob once to cycle through available inputs (RCA, XLR). The selected input will be shown on the display.
6.3. Gain Level Adjustment
- Long press the multi-function knob to switch between Low Gain (G-L) and High Gain (G-H) modes.
- Low Gain is suitable for sensitive IEMs, while High Gain provides more power for demanding headphones.
6.4. Quiescent Current Mode (Class-A)
Figure 4: Display showing 50mA (A-L) and 100mA (A-H) modes
- Double press the multi-function knob to switch between 50mA (A-L) and 100mA (A-H) quiescent current modes.
- The 100mA mode is a high current Class-A operation, offering a richer sound but may lead to a slower temperature rise.
- The display uses two colors to indicate the current level and temperature for easy monitoring.
6.5. Preamp/Headphone Dual Output Mode
The S17 Pro EVO allows independent selection between headphone amplifier output and preamp output. The current volume for each mode can be independently stored.
Figure 5: Output power for different loads and gain levels
6.6. Remote Control
The S17 Pro EVO comes with an all-aluminum remote control for convenient operation of volume, input selection, and other functions from a distance.
7. Technical Features
7.1. Twin JFET Technology
The S17 Pro EVO incorporates Twin JFETs, which offer high input impedance and a rich, tube-like sound. This design ensures consistent performance and stable mid-point voltage, making it an ideal input transistor for a headphone amplifier.
Figure 6: Close-up of Twin JFET circuitry
7.2. Powerful Output Stage
The final output stage utilizes two pairs of output transistors in parallel per channel, resulting in a total of 16 output transistors. This configuration allows for a maximum output of 7.5W, enabling the S17 Pro EVO to drive a wide variety of headphones and IEMs with ease.
Figure 7: Output stage with multiple transistors
7.3. R2R Electronic Volume Control
The S17 Pro EVO employs an R2R electronic volume chip from JRC and dedicated op-amps to construct a 4-way balanced R2R volume control. This design ensures high control precision, excellent channel balance, a wide soundstage, and accurate audio positioning.
Figure 8: R2R electronic volume control chip
7.4. Advanced Cooling System
To maintain stable Class-A operation, which generates heat, aune's industrial designers developed a complex three-dimensional cooling structure. This system integrates a heat sink on the transistor, a heat plate at the bottom, and the chassis to form a comprehensive cooling solution. Heat is efficiently dissipated through rear plate heat emission holes, ensuring stable performance.
Figure 9: Internal view of the 3-dimensional cooler structure
7.5. High-Quality Power Supply
The S17 Pro EVO features a 50W low-ripple toroidal transformer and a dual-power design. Digital control and analog circuits are kept independent to prevent interference. Additionally, a 19200µF capacitor array contributes to the amplifier's powerful and rich-sounding performance.
Figure 10: Toroidal transformer and capacitor array
7.6. Rigorous Component Selection
High-quality components are carefully selected for the S17 Pro EVO, including Hi-Fi electrolytic capacitors, ceramic capacitors, organic thin-film capacitors, and communication-grade PCBs, all contributing to superior sound quality.
Figure 11: Examples of high-quality internal components
7.7. Performance Measurements
Figure 12: Performance graphs demonstrating low distortion and noise
8. Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior of the device. Do not use liquid cleaners or solvents.
- Ventilation: Ensure that the ventilation holes are not obstructed.
- Storage: When not in use for extended periods, disconnect the power cable and store the device in a cool, dry place.
- Temperature: The device operates in Class-A mode and will generate heat. This is normal. If the device temperature reaches 69°C, the S17 Pro EVO will automatically switch to 50mA Class-A current mode for overheat protection.
9. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound output | Power not connected; incorrect input selected; headphones not plugged in correctly; volume too low. | Check power connection; select correct input; ensure headphones are fully plugged in; increase volume. |
| Distorted sound | Input signal too high; faulty cable; incompatible headphones. | Reduce input signal level; try a different cable; ensure headphones are within impedance range. |
| Device feels hot | Normal operation for Class-A amplifier; poor ventilation. | Ensure adequate ventilation. The device has overheat protection and will adjust current if necessary. |
| Remote control not working | Batteries depleted; obstruction between remote and device. | Replace batteries; ensure clear line of sight. |
10. Specifications
- Model: S17 Pro EVO
- Brand: Aune
- Item Weight: 10.38 pounds
- Product Dimensions: 14 x 11 x 2.76 inches
- Output Wattage: 7.5 Watts
- Compatible Devices: Headphones, IEMs
- Connector Type: 4.4mm Jack, 6.35mm Jack, RCA, XLR
- Power Source: AC adapter (110V)
11. Official Product Videos
Watch the official product video for a visual guide to the Aune S17 Pro Headphone Amp.
Video 1: Aune S17 Pro Headphone Amp Overview
12. Warranty and Support
Aune products are designed for reliability and performance. For warranty information, technical support, or service inquiries, please refer to the warranty card included with your product or visit the official Aune website. Keep your proof of purchase for warranty claims.
