Here’s my first attempt at a parametric equalizer. I combined parts of the graphic equalizer I did previously with information on how to make gyrators from R.G.Keen at Geofex. There’s a schematic and a vero layout, and I haven’t verified either yet. Updates to come soon.
Update (13.01.2011): Correctly labeled C1 as 150nF and not 150pF.
Update (24.02.2011): Built this circuit yesterday and I can hereby verify it as working.
Update (29.03.2011): Boxed this effect last night with a friend. This is my second take at using a transparent film for artwork and labeling, and it came out a lot nicer now. Only thing missing is a few (many!) knobs.
Update (20.10.2011): Fixed dead picture links.