Presence circuit

[12AX7]

In your opinion, in marshal style circuits what is the tonal impact of the difference between a 4.7k ground reference pus a 25k presence pot verses using a 5k pot for the presence and eliminating the 4.7 resistor? I've had both but i am unsure of what the tonal impact is but i think there is one. The way i see it the 4.7k resistor is just a way to use a 25k pot and effectively make it work like a 5k put since it's in parallel, probably because marhall had a lot of 25k pots at the time or they  got them cheaper than 5k's. But i really think there may be some sort of difference totally, i just can't put my finger on it. But when i changed from the 25k pot and 4.7 resistor to the 5k pot alone it seemed to sound different somehow. Was it just placebo effect or do you think theres a difference?

[sluckey]

The 25K pot circuit eliminates the dc on the pot and the resulting scratchy sound when you rotate the pot.

[12AX7]

I know, I was just asking about tonal differences if any. Like i said, i seemed to have noticed something.

[HotBluePlates]

... But i really think there may be some sort of difference totally, i just can't put my finger on it. ...

If you can't be sure there was a difference, there probably was no difference.