Singxer SA-2 Fully-balanced Headphone Amplifier

The SA-2 picks up where the SA-1 left off: same pragmatic exterior but with radically upgraded internals. With doubled output power, lower distortion, and improved heat management, it’s a balanced headphone amplifier and preamp designed for those who like their music honest, detailed, and powerful. Whether you’re running high-impedance headphones or sensitive IEMs, the SA-2 delivers the clean current and headroom to drive them all with confidence.

More power to play with

The SA-2’s output power boasts 10W into 32Ω, topping out at 15W into 20Ω. That means effortless control and dynamic range even with power-hungry planar headphones. It’ll drive anything down to 8Ω without issue.

Distortion that barely registers

Circuit optimizations and a new DC servo design bring the SA-2’s THD+N down to -117dB at 1kHz under an 8W load. 

Cooler heads prevail

A copper block and aluminum alloy heat sink work together to pull heat away from the circuit. The result is steady thermal performance even when you’re deep into a long listening session.

Class-A sweetness

At lower loads, the SA-2 runs in pure Class A, delivering that lush, harmonically rich tone that Class-A fans adore. Above 64Ω, nearly all its output power stays Class A, smooth, full, and beautifully controlled.

Gain staging done right

Whether you’re using balanced or single-ended sources, the SA-2’s gain options keep things flexible. Choose from low or high gain across configurations for the perfect balance between noise performance and drive power.

Ultra-low noise floor

At low gain, the SA-2’s noise floor measures just 500nV RMS A-weighted (20–22kHz). Even the most sensitive IEMs will stay dead quiet between notes. 

Ground control

A new GND/LIFT mode switch helps eliminate hum in complex systems. If you’ve ever chased a ground loop through a chain of balanced gear, this small switch will feel like a big relief.

Product highlights

• Output power up to 10W @32Ω, 15W @20Ω
  
• THD+N as low as -117dB @1kHz (8W, 32Ω)
  
• SNR/DNR >146dB A-weighted
  
• Class A operation for higher-impedance loads
  
• Copper + aluminum hybrid heat dissipation design
  
• Ultra-low noise floor: 500nV RMS A-weighted
  
• GND/LIFT mode switch for ground loop management
  
• Optimized PCB routing and DC servo design
  
• Adjustable gain for balanced and single-ended modes
  
• Output impedance as low as 0.15Ω (balanced, Low-Z mode)
  

Specs

• Output power: 10W @32Ω, 15W @20Ω
  
• Minimum load: 8Ω
  
• Distortion:
  
  • THD+N -125dB @1kHz A-weighted, 5.2V RMS preamp
    
  • THD+N -117dB @1kHz, 32Ω @8W balanced headphone amp
    
• Noise floor: 500nV RMS A-weighted (20–22kHz)
  
• SNR/DNR: >146dB A-weighted
  
• Frequency response: 20Hz–80kHz ±0.1dB
  
• Class A mode:
  
  • 16Ω <400mW
    
  • 32Ω <800mW
    
  • 64Ω <1600mW
    
• Above 64Ω: nearly full Class A power
  
• Gain (dB):
  
  • SE input → SE output: 0 / +12.8
    
  • SE input → BAL output: +6 / +18.8
    
  • BAL input → SE output: -6 / +6.8
    
  • BAL input → BAL output: 0 / +12.8
    
• Input impedance:
  
  • SE: 33kΩ
    
  • BAL: 20kΩ
    
• Input sensitivity:
  
  • BAL→BAL: High 4.2V RMS / Low 18V RMS
    
  • SE→BAL: High 2.1V RMS / Low 9V RMS
    
• Output impedance:
  
  • Low-Z mode: 0.15Ω (BAL) / 1.1Ω (SE)
    
  • High-Z mode: 10Ω (BAL) / 11Ω (SE)
    
• Preamp output impedance: 150Ω (BAL), 75Ω (SE)
  
• Heat dissipation: Copper + aluminum alloy hybrid
  
• Frequency response: 20Hz–80kHz ±0.1dB
  

What’s included

• SA-2 headphone amplifier
  
• Power cable
  
• User manual