The Topping A90 Discrete Balanced Headphone Amplifier (A90D) is a direct upgrade over it's predecessor, the Topping A90. Featuring a number of quality of life improvements including a R2R volume relay, a remote control, a ground loop noise terminator switch, a 12V trigger interface, a redesigned UI, volume memorization, and more, the A90D is better in every way.

As its name suggests, the A90D uses fully discrete components in a complete redesign of the A90 NFCA module. Four discrete NFCA modules using 39 transistors each form the fully balanced amp architecture. The matched precision transistors ensure unparalleled distortion and noise performance.