[Milsurplus] sweep tubes

[Hue Miller]

I hope you succeed in finding subs for the HV triodes. I have a BC-307

that also uses pricey tubes.

I recall looking at a prewar transformer catalog that showed many 

examples of audio amps using the the products - Thordarson, maybe?

One thing that surprised and interested me was in so many cases,

the circuits reconnected pentodes to act as either low or hi mu triodes.

I had thought that this kind of playing with the grids only began much

later, like maybe in the 1950s.

After this success, maybe you can go on to find a practical replacement

for the 2E22 and 307-A, hi.

-Hue