I have a couple of mod and filter cap questions

[Brentsp]

1) what does the 220k from the treble to the volume accomplish instead of the standard jump wire not resistance? I've tried this on some of my builds and from what I can tell maybe the highs are retained better at lower volumes?

2) The 1M to ground on the volume pot, what does it do? I've tried it and it seems to give the MV a smoother and even response for playing at low volumes without not jump in volume.



3) preamp, screens, mains, PI cans on a 100 watt Marshall. I currently have 50/50 through out but want to try 16/16 pre, 32/32 screens and PI and keep the mains at 50/50. His is an area of the circuit I know hardly anything about and have just focused on the preamp but as I get older I'm favoring lower preamp gain and more pwr tube with a bouncey feel. So what is the results of lowering the filtering in each of the 4 areas do? If you could break it down into four groups and describe it. Thank you