Electro Harmonix 300B Tubes Being Made - Russian Factory
Great video of the Expo-Pul factory producing 300B tubes. Who is Expo-Pul? They make tubes for Sovtek, Electro-Harmonix, Tungsol, Svetlana, Mullard and others.
They had a bit of trouble a few years ago. Here are a couple interesting stories regarding the factories history. Articles may be a bit older but a good bit of recent history. They picked on the wrong guy.