PSA: What they don't tell you about bass-cut guitar tone circuits

[edvard]

I got it into my head that my chinese mini-humbuckers sounded dull (they probably don't, and the amount of distortion I regularly play with makes it irrelevant anyway) and so after I read Premier Guitar's "The Fabulous Focus Knob" and "Inside Yamaha's Dry Switch" I thought it was just the ticket to cure the woof.  I tried the Focus Knob arrangement in place of my never-used tone control, and liked it immediately.  There were a few quirks, but the biggest one, and the reason for this PSA, was this:

If you have a bass-cut circuit in your guitar, low-input-impedance effects (like vintage fuzzes, especially) will make it cut even more bass than you planned, and it cuts sharper (according to a quick LTSpice session).  Not unpleasant or unusable, really, but definitely unexpected.

Just thought I'd share...

P.S.:
I also discovered that it unexpectedly affects digital effects.  My Behringer UMC202HD interface has a published spec of 1 Megohm input impedance, but the digital processing apparently thinks otherwise.