Joe and Paul - I'm not really sure, I downloaded some schematics and I'm copying them over. The preamp is for guitar to line level. The voltage is specified on the schematic. As far as how well regulated it needs to be, I'm not sure, but like I said before, I'm horrible at figuring out RC and LC power supplies like the ones in tube amps, that may have 4 or 5 voltages.
All I know is that the preamp calls for 325V. I actually have 450V coming in, but I was either gonna cascade a few of these so that the voltage drop + output voltage = less than maximum voltage for the device. The more I think about it, I'm better off with a bipolar transistor/resistor/zerenr ladder described in my last post.
like this:
http://en.wikipedia.org/wiki/Linear_regulator
