Tone stacks explained

I disagree with a lot of stuff there.
Non techs seem to love Uncle Doug, but his stuff seems invariably to contain some bad info, so I can’t recommend him, and urge caution, take what he says with a pinch of salt. He’s as likely to cause misunderstanding / misapprehension as he is to convey good info.
The narrative that ‘passive tone controls can only cut’ seems fallacious to me, such an overly simplistic starting point that the subsequent analysis and conclusion are hobbled. How can anyone hear the action of the controls in a tonestack, see the effect of the frequency response, and still think that?
My take is that the multiple filters within a tonestack interact to create a boost and cut, relative to a nominal mid range baseline.
Have a play with www.guitarscience.net/tsc/info.htm
Just need to select the appropriate tab at the top, and drag the sliders to see the effect on the frequency (and phase) response.

But passive filters are cut only. It's not fallacious, it's just how circuits work. Of course, if we think of the middle of the knob range (the 12 o'clock or center position) as zero or nominal then, yes, turning the control clockwise does feel like we're adding frequency content, but it's really *reducing the cut* in those frequencies rather than truly adding anything. And depending on how the max resistance of the pots are chosen, the fully clockwise position may still include a substantial cut relative to bypassing the tone stack. Let me state this another way...

No matter what we do to the controls, we will always have a smaller signal at *every frequency* than we would have if the tone stack was bypassed.

Apologies for my somewhat unusual perspective on the matter.
My point is that for non techs, thinking of tonestack controls as ‘cut’ only may not be particularly helpful in understanding how they affect circuit response and how to get the desired results from them.

But the above snippet may be a misapprehension.
With basic low pass or high pass filters, signal loss is low, ie at the corner frequency it’s-3dB, up or down a decade (as appropriate) it’s only 1dB.
The standard tonestack treble control is an example of a high pass filter. With treble up, signal loss in the passband is pretty negligible; lifting the tonestack will have minimal effect on the signal level in the treble range.
Using TSC, lifting the tonestack can be simulated by mid control RM pot value to a suitably high value, eg 100M ohms.
Losses there are due to the source impedance of the preceding stage RIN and its load impedance, made up of the net total effective impedance of the tonestack in parallel with whatever comes next RL.
Having a play around with TSC can be enlightening.

Am I sick in the head because I enjoy reading and learning about this stuff? I don’t pretend to understand it beyond a basic level but my brain feels strangely stimulated when all the heavy hitters chime in.

Yes…

That’s why you’re hanging out here with your kind. 😂

Lettuce? Nah, that's word salad!