Since it`s hard to google for you, let me enlighten you: http://en.wikipedia.org/wiki/Vacuum_tube#History_and_development
Btw, after having listen with Ultron PCC189 & Amperex GAC for longer period, switched to Mullard ECC88 and it "sucks" compared to GAC & Ultron. Salvatore, I think I will order 2 or 3 Ultrons instead JJ. I`m still going to buy A-frame orange from you.
Edited by CoiL - 3/30/13 at 3:28am