The Svetlana Electronic Devices (SED) 6550C is the reference standard 6550 power tube - quiet, strong, affordable and reliable. This is a brand new matched quad in original boxes. Matched quad means 4 matched tubes.

Matched octet possible, allow additional 3-4 days to match octet. We stock these, so unlimited quantities available. We offer the highest quality tubes at the lowest price on the Internet with low insured shipping costs with tracking number:
- USA: $8 USPS Priority Mail for the first quad, $2 extra for each additional quad. Flat rate $15 UPS Ground for larger quantity.
- International: $30 USPS Priority Mail for the first quad, $4 extra for each additional quad.


Insider information regarding Svetlana vs. SED Winged C:
New Sensor (a corporation based in Long Island, NY) acquired the Svetlana brand and they have been making the 6550C since 2003 at their factory in Russia. This is the same high quality 6550C vacuum tube as the SED Winged C, also made in Russia. The only distinguishing features are the fact that the Svetlana 6550C has round holes in the plate compared to the rectangular holes of the Winged C 6550C. The Svetlana 6550C sounds just as good with the same or better reliability but it is also much cheaper than the Winged C 6550C because New Sensor is a serious and savvy business with efficient distribution channels, while the other company is a bungling and inefficient operation like the a typical high-end audio company. Most tube dealers love the Winged C because they cost more and are harder to get due to inefficient distribution, so they can make higher profits with the same margin built-in - this is same way oil company makes more money with higher crude oil prices.