cap to ground on mid pot?

[joesatch]

is this a mistake in the schematic? what's this do?

[Willabe]

What does what do?

If your asking about the 2 - 220pF caps and switch, flip the switch, puts them in ||, caps add up in ||, so now 440pF feeding the treble pot, a little fatter sound.

[shooter]

What does what do?

if it's the .0047 across the 100k, it's a || RC network, sorta like a "tuned tank" to "define" what frequencies get passed down-steam n what gets dumped on the ground.

[tubeswell]

is this a mistake in the schematic? what's this do?

Not clear on which mistake you’re wondering about.

[joesatch]

is this a mistake in the schematic? what's this do?

Not clear on which mistake you’re wondering about.

the cap .0047u over the mid pot from input to ground

[tubeswell]

I doubt that’s a mistake - rather, it’s more like a ‘mistake’.

[joesatch]

wired up this way behaves strangely.  mid pot at 1 has very low mids, then at noon had strong mids, past noon up to 10 the mids progressively disappear pot on 1 or 10 sounds the same

[Willabe]

mid pot at 1 has very low mids, ....

It's at 1, no to very low mids. Mids are dialed out.

..... then at noon had strong mids, past noon up to 10 the mids progressively disappear pot on 1 or 10 sounds the same.

How does it sound/work without that cap across the mid pot?

If good, just leave it out.