Looking for a mid-range frequency booster? This one's apparently really good at it. Schematic and discussion on FSB here .

Here's an interesting opamp-based fuzz from Demeter for Fuzz Friday. I imagine other dual opamps can be used in place of the LF442, so s...

Here's a great sounding tremolo circuit from Demeter–the Tremulator. It's an optical trem, using a VTL5C1. That part can be replaced...

Here's a really nice optical compressor from Demeter. It offers vintage studio compression that's very transparent and a fairly simp...