Liang Zhu from IWISTAO 2X40W Vacuum Tube Amplifier Pull Push FU29 Power Stage 6N2 Preamp Bluetooth 5

“The Butterfly Lovers Violin Concerto“ often abbreviated as “The Butterfly Lovers“ or “Liang Zhu“. We played it with FU29 pull-push vacuum tube amplifier. This FU29 vacuum tube named FY29 in Russian, and named 829B in American. It is a composite vacuum tube in which two Cambodian tetrodes are packaged in a same glass shell. It is generally used in power amplifiers with push-pull output, which can reduce tube selection and matching trouble. FU29 filament voltage is , current is , screen voltage is 600V, curtain grid voltage is 200V, zero letter screen current is 40mA, full letter current is 110mA. The grid bias voltage is -18V, the optimal load impedance from the screen to the screen grid is 13750Ω, and the output power (effective value) reaches 44W when the signal is full. In order to further simplify the circuit, this unit uses a composite tube 6N2 for preamplification and phase inversion, so that a single channel can use 6N2 and a FU29 to co