Does anyone have a vero/stripboard layout for a one band parametric EQ? I would like to add one to my acoustic board. I'm playing a Baby Taylor and I've done probably close to 200 gigs with it. It has a dual pickup system, with a UTS piezo and a small condenser mic. When using both pickups, I'm quite happy with the sound. It's a tiny guitar, so it's not the fullest - but it's good enough. When I can't use the mic (because of feedback or noise) and only the piezo, there's a harshness somewhere in the upper mids. I think a simple one band parametric EQ would be enough to dial that out.
Did you think to use just a notch control to cut the excessive mid?
There's a Yamaha NE-1 preamp that is cut mid (no boost, just cut), with two pots: one for cut and one for the frequency. I don't remember the range frequency, but I think it's a useful mid range.
I found a schematic with amount of cut control, but that was a DIY mod version, indeed you found the original one.
Changing the 47pF with a 220pF will cut a bit of treble, But I think that's not so different. You could try both.
I think that's good on bass and on guitar, the frequnecy range is pretty wide. I never tried it, but I'm pretty sure it works fine.