I think you're going from a 6sn7 input tube to a 6h30 + more power supply stuff. I haven't heard this...but I do remember going from a VK60 to a VK75SE...The 75SE was definately quieter, better staging...deeper base but more a little more cool...that 6sn7 input tube is quite nice...
Upgrade BAT VK-55 to VK-55SE? Worth it?
I have had a VK-55 for about 3 years now. Excellent amp that I have not been able to better no matter how hard I try. I am really happy with it, but have been considering having BAT upgrade it to the 55SE. $2K seems pretty pricey for the upgrade. I have never heard the 55SE in person, so it is hard to decide if it would be a worthy upgrade. Has anyone compared the two directly? Is there a significant difference, or a small incremental gain in performance?