I have a fascination with the early technology of vacuum tubes. After looking at the tubes available on eBay I've decided to make a preampilfier using WE 101D type tubes as a model. They look fairly easy to build and I like the planar geometry of the electrodes.
The photos show my approach to doing the build. I'm going to do the construction without the aid of a glass arbor to support the tube elements and rely on the extra pins in the button pinch. Using a couple of fixtures to help in the assembly greatly improves the alignment and therefor, hopefully, the reproducibility of the tube characteristics. We'll see.