I just want to know what is the difference between the Svetlana 6550 C sold in a red boxe and the one in the blue boxe ? I was told the blue one came directly from St-Petersburg and the other from the U.S. distributor. Are the tubes of the same quality ? wich one is better ? Is the one coming from C.J are better (more expensive!!!)?
The ones which come in the blue box are the 'original' brand of Svetlana, now known as SED. The Svetlana name was bought and the new Svetlana tubes are essentially Sovteks. The Old Svetlana (SED - Winged C's) are the preferred tube sonically.