Built my own vacuum tube curve tracer hardware using high voltage transistors, opamps and opto-isolators.
20 Tube Test Jig
The Automated Plate Curve matching Curve Tracer was an idea born of necessity, as the SR 71 tube compressor is a push-pull device with no negative feedback, so tube matching totally controls the sound. This machine would pick 8 tubes out of a batch that had similar plate curve characteristics and mark the test jig sockets on the GUI with a large green dot. I could walk away and do other meaningful work and return to pluck them from their position. A remarkable time saver.
But wait, there's more! Tube Noise Measurement is also included to weed out the noisy characters. Microphonic tubes are also revealed with aplomb.
Engagement