• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Is it possible to make a +/- 12V DC Valve psu for multi channel preamp

Im planning to build a multi channel preamp / buffer where the current consumption is in the order of max 150ma for all channels and active crossovers in it. I was thinking to power it up with a valve supply. Instead of 330V DC output can we get much lower output voltage like +/-12V? 200ma?
 
It's possible, but even with damper diodes you have forward drop roughly as large as the rail voltage. :( How are you going to regulate the resulting rails? About the only thing that avoids "sand" is choke I/P filtration.

JMO, the time to use "hollow state" devices is when they do a better job than SS devices. in this situation, a CT rectifier winding feeding 4X Schottky diodes and 2 filter caps, along with 7812/7912 3 terminal regulator ICs seems to be an obvious choice.