This started as a bit of experimenting in my Guitar Signal LAB simulator and turned into one of those "wait... what is that doing?" rabbit holes.
I ended up building it into a real guitar to see what would happen.
Check out the new video →
This one has been a bit of a rabbit hole!
I built my own simplified version of Grant Wills' Baking Tray Tube Tester and have spent the last few months putting it through its paces in the workshop, including testing hundreds of guitar valves alongside my commercial testers.
I also built a free online app to go with it, which takes the actual HT voltage, grid bias and plate-current readings and turns them into a simple valve-health result.
The video is up now if you'd like to see how it works and how it compares with the commercial testers.
And as always, a massive thank you to all for supporting what I do. ❤️