I'm sorry if this topic has been covered in another thread. How do I calculate the resistor values in a tube rectified power supply? I have a Hammond 269jx transformer, 500V CT . I'm using a 6x4 rectifier. The unloaded voltage after the 6x4 is approximately 330V. I need to supply a circuit with 295V @ 30 milliamps. The trans is rated 250-0-250 @ 69ma. How do I calculate the resistance needed to drop the 330V to 295V?