SGR,
I will do an article on this at PTAudiophile soon to sort out the confusion.
1)Correct. Some people prefer the big box rather than 2 separate smaller boxes and other prefer the inverse.
2)Plain vanilla DSD ( what is used as the format on SACDs is DSD64...ie ibit 2.8mhz). DSD128 is double rate DSD, ie double data rate 5.6mhz. Twice the size and a bit better SQ, probably due to the fact that the ultrasonic noise is pushed even further away from the audible frequencies.
3) ECC40 has great SQ, but is less robust that 182. I dont know the characteristics of all, but a buddy just switched from 40 to 182 and prefers the latter. 182 is more robust as well, but also more expensive.
4)I agree here.
5) He uses either 6x5 or 5Y3 rectifier tubes. Both kinds are supplied stock. I think there is more tube rolling possibilities with the 5Y and consequently more upside from tweaking. I have the 6x5 and am happy enough. I did find a few at Ebay to try rolling with.