With its TA-66, xDuoo presents a headphone amplifier / preamplifier with tubes. The TA-66 features two tubes: a 6N2 tube for the preamplifier and a 6N5P tube for the buffer. These tubes amplify and process the signal, producing a final sound with smooth vocals and a round, colorful tone. The special feature of this headphone amplifier is that it uses a point-to-point soldering technique to connect its tubes to the rest of its components. This technique shortens internal wiring distances and protects the signal from interference for a clean sound. The Xduoo TA-66 features essential connectivity, with a stereo RCA input, a 6.35mm headphone output and a stereo RCA preamp output. A large potentiometer on the front panel controls output volume. This headphone amplifier/preamplifier is ideal for headphone listening, with the option of preamplifying a signal for a power amplifier or active speakers.