I lived with a pair of Harbeth C7 for about a year using a Rogue Cronus Magnum 2 amp. From my experience tube amps seem a bit slow for the Harbeth. I would go for a SS amp, something like a LFD, Naim, Sudgen, Hegel or Exposure. All great matches for Harbeth. I haven't listen to the VAC but I did have a chance to listen to the Leben and I will say that the Leben CS600 sounds very good with Harbeth speakers. With that said, I still would personally would go with a SS amp. Although, I did not end up upgrading my C7s and selling them, I was very close to getting a pair of SHL5+ and the Hegel H360 amp. Good luck!
