Older guide for 300B tubes – some tubes in the list are not produced any longer – Still worth reading. In Search of the Perfect 300B Tube
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Guides and reviews of vacuum tubes and audio equipment
Older guide for 300B tubes – some tubes in the list are not produced any longer – Still worth reading. In Search of the Perfect 300B Tube
And here is another one from HI-Fi World DIY Supplement. Read NOW
Here are a few more from Enjoy Music
http://www.enjoythemusic.com/magazine/equipment/1201/300b/
http://www.enjoythemusic.com/channel/ch300b/