Quote:
Originally Posted by dobulee
Definitely! Spending some time looking at it in detail. It's sort of a quasi paraphase phase inverter?
|
Back in the day it was called a 'grounded grid, common cathode' phase inversion scheme.
During half a cycle, say the grid of the 1st tube swings positive> cathodes go more positive, making the grounded grid of the 2nd tube negative relative to cathode.
Truth be known, the balance wasn't perfectly symmetrical but consumer grade with minimum parts count, and still be "push-pull". The balance was probably on a par with the scheme using the 6AV6 inverter. To tailor the gain, looks like they chose 220K for the plate load resistor and 220K for that series resistor going to the grid.