has anyone built a real mctube or similar preamp? looks real cool, i like the backwards transformer for the high voltage for the tube. it seems like a better option than the starved plate designs that are out there, anyone have any thoughts or experience?

can the voltage rating on a filter cap be too high?

ive got a traynor reverb mate 40 that a friend brought to me to repair it has two tda 2030 amps for its power section, one was destroyed ( it looked like it had exploded) and the other one didnt work when i put it in another 2030 10 watt amp.  he got the amp from his cousin  along with a bass guitar that he had been playing through the amp. 
i am replacing the 2030s and i also am socketing all of the opamps in the preamp/chourus/reverb sections for purposes of experementation.  i wonder if anyone has any experience with such an amp and could offer any input, or comments. i am still reletively new at this stuff, i am self taught and still learning. i have built several stompboxes and 386 type amps but i am just getting into amplifiers so any help is welcome.