Topping has just announced its latest headphone amplifier called A50s. As you might have guessed already, it’s meant to pair with D50s I’ve already reviewed. It boasts similar CNCed aluminum chases as D50s which grants a neat-looking stack for the owners of both devices. Topping equipped A50s with both single-ended 6.35 mm and balanced 4.4 mm headphone output, increasing its versatility.
Topping A50s will deliver up to 3.5 W of power into 32 Ohms & 760 mW in 300 Ohm loads on its 4.4 mm balanced output with both channels driven. When using a source that provides a signal level of 2 Vrms, the A50s will output 1950 mW into 32 Ohms and 208 mW into 300 Ohms. The gain levels of the A50s allow for easy switching between 0dB/6dB (single-ended) and 6dB/12dB (balanced). This gives users the ability to adjust the headphone amplifier according to their needs.
On the back, we find a set of RCA inputs as well as outputs, meaning that A50s can act as a preamplifier too. Unplugging headphones activates the analog preamp mode of the A50s. Preamp mode automatically switches the headphone amplifier section off. Plugging the headphones back in starts the headphone amplifier section and deactivates the preamp section, allowing the A50s to act as a pure headphone amp or pure preamp, but not both at the same time.
The near 0-Ohm output impedance of the A50s produces a high damping factor that minimizes frequency-based reactive-load impedance shifts and ensures a predictable frequency response. The high damping factor ensures adequate control over the connected headphone’s drivers, allowing for powerful bass and accurate sound reproduction.