Low Voltage Triodes

It is possibly not the triode themselves but the way they are biased.


For example, the Pleiades V6 schematic (shown a triode connected EF183):




The Pleiades bias resistor is usually 6MΩ. It can be less for less anode voltage.


A Nuvistor 7586 triode can also be used. Using an 1.8MΩ from anode to grid both EF183 and Nivistor 7586 can operate at less than 1./V anode potential. See previous posts.


Possibly an ECC82 too. So far tested at 4V. See Pleiades V2, Pleiades V3. 7025 a good candidate. CV2269 operating with less than 1.2V. See previous posts.


Further reading:


The Pleiades Bias - euroelectron


http://euroelectron.blogspot.com/2015/10/pleiades-electra-13v-electron-tube-pre.html



http://www.valvewizard.co.uk/Triodes_at_low_voltages_Blencowe.pdf


Even an open grid can impede electrons:
Operating Features of the Audion - E. H. Armstrong