The schematic for the
Simple SE:
This is the schematic for the Simple SE amplifier. All optional features are shown. The mode (Triode / UL) switch, the Cathode feedback switch, the standby switch, and the rectifier switch are optional, and should be jumpered into the desired position if they are not used. The optional power supply choke and the optional auxiliary power supply capacitor are simply left out if not used. R1 and the choke should not be used at the same time. Install one or the other. A choke (even a cheap one) is recommended if high efficiency speakers are used.
This is a copy of the Eagle schematic that was used to design the PC board that is used in the Simple SE amp. It does not show the connections that are external to the PC board.