Input impedance on buffer pedal (VARI-Z)

[zosotone]

I am experimenting with some buffers, the Cornish and Stupidly Awesome Buffer mainly on my pedalboard and I think that it's a nice idea a input impedance control for set de hi end.

I put the buffer the first pedal on my chain but some many times it's too sharp for my taste.

With the Stupidly Awesome Buffer can I replace the first 2M2 input resistor with a 1M pot?



makes sense?

Also, I found the tube buffer Sarno Steel Guitar Box, that has a Vari-Z control:

[zosotone]

Also, Okko makes the Variable Input Bufer pedal, that sets the input impedance and the capacity.