We’re fairly certain production of the SED Winged “C” tubes has come to an end. We have purchased as much stock as available from them that was not factory seconds. We were offered factory seconds at a lower cost however we declined. We do know these factory seconds have entered the marketplace.
Our price has been raised to reflect the higher purchase cost of this final product. SED Winged "C" tubes should now be considered NOS (New Old Stock).
The Winged "C" (SED) 6550C is an ideal replacement for amplifiers with GE 6550A tubes.
From our 6550 tube type listening test: "The Winged "C" 6550C has very controlled sound - nothing offensive can be found in any part of the frequency response. Also very consistent in detail and separation, with clean highs and exceptional balance throughout."
This 6550 tube is a popular choice in Audio Research amps.