What is SED? (yeah it's a n00b question)

[Ailean]

Ok, I understand the various types of valves, but I keep seeing references to SED 6550's. Is SED a manufacturer? Is it a moniker for a particular type of 6550, like the winged C? What does 'SED' mean?

Cheers in advance!

 

[King Guitar]

SED is a brand name of tubes.

Here you go: http://www.sed-usa.com/

 

[Ailean]

Cheers dude!

Probably explains why a trawl of UK sites didn't get me very far.