Here's another tonestack with the addition of Mirosol's LPB1. Again, I have not built this so its not verified.
Would appreciate help in ensuring this is correct. I will be using this also in an upcoming project.
Again, thank you Mirosol for creating the BMP w/LPB1
if im not mistaken it's input impedance from the cathode follower network that comes before the tonestack. the Duncan tone calculator just substitutes an equivalent resistor value to take the place of the cathode follower circuit that drives the tone stack. but i could be wrong.