high voltage regulator

[wleediy]

I am now interested in regulator as even the serial reg do improve the amp sound.
In my friend Cj PV 6 tube amp, The regulator for the high voltage B+ is consist of MJE 340 controlled by MPSA 42. The output is about 380 Volts DC, while the input could be as high as 470 Volts due to the high AC of 242 V vs the transformer stated 230V primary.
As I increase the smoothing capacitors, the voltage rose to near 500V and blowed out the MJE 340 and MPSA 42. I am thinking of using MJE 13034 to replace MJE 340. Could any one suggest modern replacement for MPSA 42, and MPSA 92?
What if I use CMOS 2SK2769 which could be found in lots of switching mode PS? Will it sound better then bipolar?

tks and rgds

William

[ikoflexer]

Probably more people would try to be useful if you post a schematic.

[wleediy]

Yes tks, the schemetic is too big, here is the link:

http://www.drtube.com/audioamp.htm#CJ

or

http://images.google.com/images?q=conrad+johnson&rls=com.microsoft:en-SG:IE-SearchBox&oe=UTF-8&sourceid=ie7&rlz=1I7ADBR&um=1&ie=UTF-8&ei=6N53Sr-nNoOHkAWI6IC0Bg&sa=X&oi=image_result_group&ct=titl e&resnum=5

William