Here I would put a quick review regarding my headphone amplifier. As same as general VFD, fluorescent material is prepared in Nutube and we can enjoy small light during operation. (This is just light-on, not sound indicator such as magic-eye)
Actually This amplifier can be battery driven. In my design NJM2884 is used for 3.3 V regulator and its maximum input is 10 V so around 10 V is the maximum DC power source. As for the current, I confirmed,
which is really small for the case of vacuum tube amplifier!!!
Actual operation can be found in the following movie. As same as another project, I have a plan to sell this kit at tindie.com around $90 (sorry so expensive, but Nutube alone costs $50 and MUSES 8920, capacitor, PCB fabrication accumulates the total costs...!)