I got the word that Ei tube factory in Serbia (former Yugoslavia) has shut down production.

They've been making tubes for 50 years. They had ties with Telefunken and Dutch Philipps.

While many people seemed to really like Ei tubes for thieir sonics. Ei tubes have been plagued with quality issues in recent years and factory production output became minimal. I'd venture to guess that recent skyrocketing oil prices had direct effect on this outcome.

Their KT90 was a superb tube when they made it right. Unfortunately, EI KT90 started showing quality issues some time ago, but I was really hoping they would address it and start shipping this wonderful tube again. I'm really going to miss this tube.