BAT VK75SE or ARC VT100 mk3

"All I know VK75SE is TRIODE power tube while VT100 is FET,6H30,TERTODE TUBE"

You need to know more than that before you buy either amp. If you want to make a successful purchase, you'll need to make the decision based on your own experience with each amp and not just opinions of others. How did you even come up with those 2 amps in the first place?

I have not experienced the VT100, but there are several relatively simple modifications that can be done to make the VK75SE more resolving, dynamic, and neutral. PM if you're interested.

I found the VT100 to sound like SS. YMMV.

"10-06-14: Keithr
I found the VT100 to sound like SS. YMMV."

Did you have the 3's with 6h30, or the 1 or 2?

OP,

"All I know VK75SE is TRIODE power tube while VT100 is FET,6H30,TERTODE TUBE"

I'm pretty sure the BAT has 6h30's as well. I think all of their SE tube products use them.

I heard the full ARC VT3 system several times- and owned the VK75SE with 6h30s.

I strongly prefer BAT to ARC, but to each their own. I just find those old ARC amps really dry. The latest Ref 75 is better, though still not quite my cup of tea.