TerrySmith
What your doing is great. There is nothing wrong with your design however if it were me I would increase the size of the caps after the output stage. You may find that it sounds better. One might also install 2) 75 ohm resistors in the power supply to knock down the voltage just a tad.
I like to use a damper diode tube to keep the slow turn on and end up with roughly 21 or so volts less.
Years ago I got a Dynaco from SY on the diyaudio board. SY had modified the power supply quite a bit and it sounded awsome. He used some stocky caps and the sound was very quick and punchy without being muddied up. It takes a little of experimentation to arrive at what I feel sounds the best for each individual driver board and amplifier.