Recently I have been doing some experimentation with 6V6 power tubes. As I was looking over some old designs I realized that I really wasn’t designing the 6V6 power stages so much as picking values and hoping for the best. This led me to develop an entire set of operation data on operating the 6V6 in Single Ended Ultra Linear (SE-UL) mode. You can read the results here (http://www.cascadetubes.com/optimization-of-the-6v6-se-ul-amp/) or over on the DIYAudioProjects site (http://diyaudioprojects.com/Technical/6V6-SE-UL-Bias-Optimization/). But it also got me thinking more generally about a common problem we all share, a general lack of resources to support the vacuum tube circuit design process.

Of course I will start by saying that the one truly great resource we do have is the DIY community. Through online forums like DIYAudioProjects we can share designs, discuss circuits, and ask and answer questions. This allows not only our own growth but the growth of others, and the DIY community itself. But what about technical data? What about raw information concerning specific tubes or amplifier configurations? Here our resources a spread more thinly.

There are textbooks of course (“The Theory and Application of Electron Tubes” comes to mind) and design manuals (such as the RCA “Radiotron Designer’s Handbook”) but these are really geared to the trained Engineer not the weekend hobbyist exploring the technology of a bygone age. There are tube data sheets but these can be almost as infuriating as having no data at all. They contain some general information a few design point solutions, but never anything which could be called comprehensive.

Personally I have taken to experimenting and generating lost of graphs, notes, and spreadsheets detailing the operation of various tubes and circuits. The 6V6 data referenced above is a good example. I am curious, what others have done. Drop me a note and let me know how you handle this situation. Maybe you’ve found something that works which I haven’t.