Cayin iDAC-8 uses vacuum tubes: 6H6b-B double triode
Single-Ended Mode: Uses 2x 6H6b-B tubes, one for each channel. Within each tube, two parallel triodes form the first stage of the circuit, acting as cathode followers to improve current-driving capability and reduce noise. A fast-turning, low-resistance Vishay MOSFET is used in the second stage as a voltage follower for improved performance.
Balanced Mode: uses 2x 6H6b-B tubes, with two triodes in each tube designed to amplify the current and drive the positive and negative phases of the same channel.






