My attempt in making a ruben's tube that uses LEDs instead of live flames.
So i finally got around to test the rubens tube more. What I did this time, was noting where are the peaks and the bottoms of the waves when a 400hz is played into the tube. Then I mounted cheap-ass microphones from ebay into three of the positions. Played the 400hz signal into the tube again and inspected the microphone output on an oscilloscope. I was very glad to find out that a clear difference between these points could measured! This measn that I should be able to digitize the tube.
So I finally got my Ruben's tube working. As there are many instructions online, I will not go into many details. Basic steps I took:
First I did some shopping and basic preparation. I got myself: