@thebiglebowski, sonetduo is right, it's not a vfet preamp, at least according to the official specs
I just got the Hitachi working. Well, she's not a bad amp, but she's not even close to the B-2 or the B-3. Sure, she's an integrated amp and wasn't even hi-end at the time of the release, but I soft of expected more. Every possible aspect of the sound is worse, except maybe for the bass response, which is quite good.
C1 is still under repair, as well as N7B. I hope it's going to be done soon.