opa1 wrote:Thanks! The 5881's look interesting. Any brand in particular?
Almost all of them were made by Tung Sol or Sylvania both are good NOS are getting expensive , the new ones are Russian or reissued Tung Sol .http://tubedata.tubes.se/sheets/127/5/5881.pdf
I have RCA and GE branded made by Tung Sol that i use .