I borrowed a Primaluna integrated (Prologue) from my local dealer recently and it sounded fantastic! This was my first foray with tubes and I was impressed by the impact and large soundstage; nice, tight, deep bass too. I've never heard the LS50's, but I can vouch for the Primaluna. Another great amp in your price range is the SimAudio 250i. Occasionally, you'll see the Sim i-1 (original 250i) for about $800 on Agon. I liked it so much I eventually bought their 700i.
Amp recommendation for KEF LS50
I’ve had the LS50’s for a while now and have been saving up for a new integrated to power them. Currently using Rotel ra-12 which sounds good but I was wondering if anyone had any recommendations in an amp that pairs well with the KEF’s. I have a budget around $2k and can stretch to $2,500 if need be. Not many dealers in my area so any help would be greatly appreciated! Also, room is roughly 12x15. I have added room treatment to help as well.