Heater Pots?

[Agi]

What's the idea behind having a 500k pot in between pins 4/5 of my 6n1's to gnd?

I've just dismantled my mini meng (6n1 and 6p1) to point to point it instead, but I couldn't see the point of them being there??

The 500r trim in the bottom right:

Anyone shed any light?

 

[llwhtt]

The heater supply has no center tap, that means lots o' hum, so the pot creates one. It's a 500 Ohm not 500K. Adjust it for minimum hum from the speaker.

Craig

 

[Agi]

😀 i even put 500r the second time around.

Thanks a lot for that, i'll make sure they go back in then. 🙂