A Class B2 tube amplifier
Output tube is 1635 twin triode
Class B2 means it run at positive grid voltage,
this requires very low impedance driving, and very well-regulated power supply.
This amplifier uses two 6N6P working as cathode followers to drive the 1635 grids,
and Mosfet regulators for B+ supply as well as current supply for the 6N6Ps.
The input and phase inverter stage are 12AU7 and 6AQ7 differential pair respectively.
Good Sansui H10-10 output transformers.
4, 8, 16 ohms output selectable.
The amp. runs at very low idle current so it is a cool tube amp.
Clean 10W on 8 ohm verified on oscilloscope.
The sound as tested was clean and strong.
Dead quiet at no signal.