I had the Andra 2's for a while, although they are supposed to be a bit more efficient than the original Andra's. I feel that the 2 needed alot of power. I could not imagine the VK-60 being even close to enough power with this speaker. The Vac 300.1's are a healthy 150 wpc IMO, but driving my Vandersteens with a powered woofer I believe is an easier load than Andra's. It's a very nice speaker, but not a tube friendly one. I think Kurt's suggestion of the VTL is the best if you want to make these sing. The Air Tight ATM-2's are a powerfull 80 wpc, but 2 in mono exceed 6k on the used market. If you go VTL, you may want to try KT-88's. I did not personally do it, but a good friend swears by the 88's in his VTL's.
