An upgrade of the TA-20, the TA-20 PLUS from xDuoo features a number of improvements. This fully symmetrical Class A tube headphone amplifier now boasts a 5Z4P correction tube in addition to its two 12AU7 amplification tubes, for an even warmer, more rounded sound. It now also incorporates a VU meter on the front panel, and an aesthetic design that's more stretched across the width, even though it remains very compact. It also adopts Class A transistors, enabling it to develop considerable power and drive headphones with impedances ranging from 16 Ω to 600 Ω. Its comprehensive connectivity makes it easy to integrate into any Hi-FI installation. xDuoo's TA-20 PLUS features a fully balanced circuit between the XLR inputs and the balanced headphone outputs. This enables this headphone amplifier to achieve excellent performance, with a crosstalk of 95 dB, an SNR of 113 dB and a THD+N of just 0.05%.