The problem lies in the fact that there are a lot of NOS KR tubes around today being sold by "unauthorized" KR dealers who are "actively" misrepresenting themselves as USA distributors. If you google KR tubes USA you will get the USA KR distributor but when you go to KR's main website it makes no mention of said USA distributor and directs you to another USA site.
KR has a lot of rogue dealers who offer no warrantee support. My buddy bought a pair of ballon 300b which ended up have some loose internals and was not offered a replacement. He is so worried about a short, the tubes remain in a box.
I wouldn't recommend KR tubes based on my experience and knowledge. If one does decide to go with KR tubes, I would contact KR in the Czech for an authorized reseller. My 2 cents.
KR has a lot of rogue dealers who offer no warrantee support. My buddy bought a pair of ballon 300b which ended up have some loose internals and was not offered a replacement. He is so worried about a short, the tubes remain in a box.
I wouldn't recommend KR tubes based on my experience and knowledge. If one does decide to go with KR tubes, I would contact KR in the Czech for an authorized reseller. My 2 cents.