Our second revision of this PCB, smaller footprint, higher output currents. A compact, regulated power supply suitable for tube preamps, line amps, and microphones. Can supply up to 5A at 6.3V or 12.6V and up to ~250mA at 300V with adequate heat sinking. Max B+ voltage is dependent on input AC and is set by a Zener string on the board. Using the recommended IRF830B DC B+ voltages of up to 450V can be easily achieved, just remember to scale your capacitor working voltages to match the output, and ohm’s law to be sure you don’t exceed the dissipation of the MOSFET.
We cannot stress enough: if you’re going to pull more than 3A or so of heater current, or more than 50W dissipation on the IRF830 you absolutely must have a substantial heat sink in place to avoid thermal shutdown or potential component damage.