The Singxer SA-2: more power, more control

The Singxer SA-2 is the successor to the acclaimed SA-1 headphone amplifier and preamp. While its exterior remains familiar, nearly everything inside has been re-engineered, from its power supply to its thermal design, to deliver cleaner current, higher output, and lower distortion. The result is a fully-balanced, Class-A-capable amplifier with serious drive capability, even with the most demanding headphones.

A significant power increase

The SA-2 doubles the output of its predecessor, delivering 10 W into 32 Ω and up to 15 W into 20 Ω. It comfortably supports headphones with impedances as low as 8 Ω, making it suitable for virtually any load, from sensitive dynamics to current-hungry planars.

Lower distortion, higher clarity

Singxer reworked the internal circuit layout to minimize distortion, even at high output levels. The result is THD+N performance as low as -117 dB @ 1 kHz (32 Ω @ 8 W) and a signal-to-noise ratio greater than 146 dB A-weighted. This gives the SA-2 a pitch-black background and a sense of clarity that lets your source components shine.

Class-A tone without compromise

Below 800 mW @ 32 Ω, the SA-2 operates in pure Class-A—offering the harmonic richness and warmth that define the topology. Above 64 Ω, nearly all output power remains Class-A, ensuring effortless control across a wide range of headphones.

Built for control and reliability

A redesigned heat-dissipation system uses a copper block paired with an aluminum alloy heat sink for stable thermal performance. A GND/LIFT toggle helps eliminate hum in complex systems, while flexible gain options make it easy to optimize the amplifier for different sources and headphones.

Technical precision

Every part of the SA-2’s design reflects a focus on measurable transparency and reliability. PCB routing has been refined, DC biasing adjusted, and a DC servo added for stability. The amplifier offers extremely low output impedance—0.15 Ω balanced, 1.1 Ω single-ended—ensuring precise damping and control.

Specs

• Output: 10 W @ 32 Ω / 15 W @ 20 Ω
  
• THD+N: -117 dB @ 1 kHz (32 Ω @ 8 W)
  
• SNR/DNR: >146 dB A-weighted
  
• Frequency response: 20 Hz–80 kHz ±0.1 dB
  
• Input impedance: 33 kΩ (SE), 20 kΩ (balanced)
  
• Output impedance: 0.15 Ω (balanced Low-Z), 1.1 Ω (single-ended Low-Z)
  
• Gain: Selectable low/high per input/output configuration
  
• Heat management: Copper + aluminum alloy sink
  
• GND/LIFT switch
  

Available now

The Singxer SA-2 is available now on Apos Audio as a fully balanced desktop headphone amplifier and preamp built for accuracy, control, and long-term reliability.