This is the bare PCBs of two channels of high-end Amplifier End version 2022 by the designer, audio expert Mr. Andrea Ciuffoli. This amplifier is the best sounding amplifier Mr. Andrea Ciuffoli have designed. According to the words of Mr. Andrea : "If we compare this amplifier with my last Power Follower 2021 we have a higher transient speed obtained by driving the mosfets with a lower impedance and higher current. The mosfets used have also have a lower input capacity than the IRF and there is another dynamic while still maintaining the purity of the sound of the Power Follower. The main benefit of a Circlotron design is an high power amplifier with no switching output stage like a pure class A but higher efficiency, with only 1A bias current still 1mA with 2.3A on 8 ohm load." Specifications: Pout = 60w on 8ohm with 1.5% thd Pout = 105W on 4ohm with 1.6% thd Pout = 21W on 8ohm no-switching with 1A bias Pd = output stage 2 x 1A x 38V = 76W each channel with 1A bias Zout = 0.4ohm to have a damping factor of 20. Ft(-3dB) = 20Hz-56KHz at 0dB and 10Hz-65KHz at -3dB This board set includes : 1. amplifier boards two pieces ; 2. input transformer boards two pieces ; 3. driver and PSU board one piece ; 4. rectifier diode boards four pieces. We do air shipping worldwide at US$8.00. We welcome combine shipping.