There is some good information at http://www.upscaleaudio.com/
Some NOS fakes are semi fakes. There are tubes that were made at one time in Japan from the original manufacturers specs. So these tubes are fakes, but sometimes very good ones. Some fakes are "rebranded".
Some NOS fakes are semi fakes. There are tubes that were made at one time in Japan from the original manufacturers specs. So these tubes are fakes, but sometimes very good ones. Some fakes are "rebranded".