05-11-2016, 09:28 AM
That's an interesting concept!
If the p-p transformer was UL, then the screen-grid currents would all flow through the difference transformer. So for each transformer, they would contribute to the output. However, if you applied a pure mono signal at the input (both grids driven in anti phase), the thing would look like a UL push-pull amplifier; if you applied the mono signal with both grids driven in-phase, it would look like a SE triode amplifier! All rather horrendous when it comes to trying to optimise the transformers, calculate output power, etc!
If the p-p transformer was UL, then the screen-grid currents would all flow through the difference transformer. So for each transformer, they would contribute to the output. However, if you applied a pure mono signal at the input (both grids driven in anti phase), the thing would look like a UL push-pull amplifier; if you applied the mono signal with both grids driven in-phase, it would look like a SE triode amplifier! All rather horrendous when it comes to trying to optimise the transformers, calculate output power, etc!
