Ts4d Motorola

[timmy]

Originally Posted by jr_tech

What do you hear if you disconnect the grid (pin 2) of the 25L6 audio output tube.

jr

I didn't disconnect anything else but pin 2 of the 6sq7, still humming.

[jr_tech]

Originally Posted by timmy

I didn't disconnect anything else but pin 2 of the 6sq7, still humming.

So now i'm asking what happens if you repeat the experiment on the next (last) audio stage.

jr

[timmy]

Well I could take off pin 2 but nothing will happen, heater. Or you meant grid I think ?

[jr_tech]

Originally Posted by timmy

Well I could take off pin 2 but nothing will happen, heater. Or you meant grid I think ?

Yes, grid, pin 5, sorry for the confusion.

jr

[timmy]

Pin 5 off hum even louder with no hiss as if there was no ant.

[jr_tech]

Interesting.

What happens if you connect pin 5 of the 25L6 to either end of the cathode resistor (330 ohm R-38) ? Try both ends.

jr

[timmy]

Originally Posted by jr_tech

Interesting.

What happens if you connect pin 5 of the 25L6 to either end of the cathode resistor (330 ohm R-38) ? Try both ends.

jr

After the grid wire was put back on?