On a flashback of the episode Canelina and her friend connect a few megohms from anode to grid while using the microphone on ambient noise and the electron tube amplifier operating with 6V at anode suddenly becomes much more sensitive and low noise.
On flash forward after Canelina dreams of a Nuvistor electron type to be used on the Pleiades V6 mic head amp searches with the patient tortoise on Google for Nuvistor datasheets. By chance the come across to the one-half watt RCA Nuvistor report to a U.S. Navy contract.
By reading the references on electron tube fluctuation noise and measurement techniques they come across the classic noise papers and therefore obtain precious scientific backup for their re-discovery of the merits of low cathode temperature and low anode voltage on approaching the ideal noise behaviour on electron tubes.
They ponder how greatful they are to the wise girl Hliana who insisted that the negative self biased grid (by the missing electrons on the emitting cathode) should be pulled up by a positive voltage source to free electrons and making very low anode voltage operation possible. The mic sings.
Canelina jumps up from joy. And they all go to the beach and together with the wise seaguls sing and dance while swimming under the sun who leaves no shadow to the truth.
References:
The design and development of one-half watt heater power reduced size Nuvistor triode - Defence technical information centre
http://www.dtic.mil/dtic/tr/fulltext/u2/294926.pdf
Operating features of the Audion - E. H. Armstrong
On preserving transconductance of electron tubes at an anode potential as low as 3 Volts - euroelectron
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