My first voltage multiplier PSU. 😎 (...for tube mics)

[trobbins]

If you have a 1 ohm or 0.1 ohm resistor then fit it in the transformer leg to the first 1,000uF 50V cap and use a true rms meter to measure the ac voltage across the added resistor, and then calculate the ripple current passing through the cap. Then try and find a datasheet for the actual cap you are using - perhaps circa 1.0A ripple at mains frequency.