I am running a vk60 amp in replacing my Biamped Bryston 3BST driving my pair of Norh Marble 9 Speakers (87db). Before I hook up the vk60, I was always concerning the bass may shy from the 2x Brystons. However, as soon as I play the 1st track of Jenifer Warran's Hunter CD, I noticed tears are running down to my cheeks with my draw down on the floor. Not only the vk60 gives the depth, texture and 3D holographic imaging, bass is tighter than my Brystons. Yes, the room tempeture is higer but all I have to do is move the vk60 further away from me and would be ok. Since the vk60, I am totally convinced with BAT and I purchased the VK30SE. Wow, it was another quantum leap to my system.. The synergy is just unbelivable. Now, I know what is sound stage, what is bass and what is 3D imaging. Now, the vk30SE has served in my system for a while, I am on the path to VK31SE or 51SE for futher sonic improvement.