Korg is making (and selling) this low power, low voltage vacuum tube twin triode
- Vcc : 5-80v
- 12mW per channel (it have 2 channel)
- Korg Nutube 6P1 Dual Triode – diyAudio Store (price is per unit resell pricing, not manufacturer price)
- lot of video and webpage about it
it seems to be really easy to use.
(And it looks nice.)
a bit expensive but not unreal for a eurorack module.