(http://korgnutube.com/en/)
Nutube, similar to a conventional vacuum tube, has an anode grid filament structure, and operates exactly as a triode vacuum tube. Also similar to a vacuum tube, it creates the same characteristic rich overtones. By applying their vacuum fluorescent display technology, Noritake Itron Corp., a Noritake Co. Ltd affiliated company, have devised a structure which achieves substantial power saving, miniaturization, and quality improvements when compared with a conventional vacuum tube.
But even more interesting is that the first Nutube based products are actually out at consumer level prices:
http://www.voxamps.com/MV50AC

https://www.thomann.de/gb/vox_mv_50_ac.htm?ref=search_rslt_nutube_406235_0
Did anyone try that?