This project contains the components for the power supply of a 40W tube guitar amp using an Antek 1T350 (100VA, 350VAC) or similar toroidal power transformer. It provides about 420VDC @ 120mA (plates), 6.3VAC @ 3A (AC filaments) and 12DVC @ 1A (DC filaments). The amplifier contains 4-5 preamp tubes operating from the DC filaments supply, a phase inverter and output stage operating from the AC filament supply. Power output stage is a PP pair of 6L6GC's or similar. The supply circuit on this board also contains a negative bias supply designed to provide about -38VDC for the 6L6 grids. This supply uses a charge pump operating from the high-voltage transformer secondary through C8/C9 coupling capacitors. The HV secondary includes a snubber to reduce noise, and the primary is protected by a surge limiter.
The board is designed to mount underneath (really, above, since the guitar amp's physical arrangement is the typical Fender-like upside-down chassis mount) the transformer, inside the 1-3/4" deep chassis. The drawing below shows the relationship of the components.
The project is on hold for a bit, while I finish up the overall design and construction of a 12W guitar amp, using the 50VA power supply design I recently released. I will be modifying the 100VA design to include all of the filter capacitors, mounted to the PS board, eliminating the traditional capacitor tank.