If it doesn't glow, it doesn't go ;)
I've seen this mentioned by John Broskie in his post on TubeCad. I agree :)
Tubes are sexy. They look sexy and the work as a perfect input device too.
We've got two hybrid designs on the list at the moment:
- A rather simple and inexpensive TubeHex
- The great addition to NS Modular family TubSuMo SMD front-end
The latter can also be used in combination with very simple OPS - only 4 x lateral MOSFETs - if you can find the genuine ones these days.