I thought I asked this last week, but maybe I failed to hit the 'create thread' button, so I ask again. I am building a Fender-ish push-pull amp using 6V6. I see that some amps (musicmaster bass, 5F1, 5F2-A) have the signal entering pin 5, and pin 6 is unused. Others (5E3, 5E5A) have the signal entering Pin 6 with a 1500K resistor jumpering to Pin 5. Obviously both work. What is the difference (meaning, which should I do)?