guys, i've been reading up on the Tungsol 6550 tube.... it seems that there are new production tubes made in Russia (by Sovtek).... the original tube was made in the US in the 1950's.
Sovtek has acquired the rights to the Mullard and Tungsol brand names and have re-issued the Tungsol 6550..... they will also be releasing new production Mullard EL34's
.....the specs are said to be the same as the original but as to whether they can duplicate the sound of the original remains to be seen..... initial reports from buyers of the new tubes are positive, though strangely i have yet to find a side-by-side comparison between the NIB and NOS.
new production