CGS Serge resonant equalizer: Difference between revisions

m (Text replacement - " (archived) by Ken Stone, 2010, with permission of the author" to " by Ken Stone, 2010, with permission of the author - archived")
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== A little on how it works ==
[[File:cgs_schem_cgs202_res_eq.gif|thumb|center|800px|Click through to view an enlarged copy of the schematic.]]
=== Note from Aaron Lanterman ===
I wanted to share some research I've been doing into the Serge Resonant Equalizer, with the help of Serge Tcherepnin, Yves Chartier, and many folks on the [http://synth-diy.org/pipermail/synth-diy/2022-December/thread.html#130816 SDIY mailing list].
 
The top three filters on the CGS schematic are incorrect. The input of the 2nd op amp should be taken from the + input of the 1st op amp. The resulting filter is a "ideal current-inversion negative-immittance converter (INIC) bandpass filter" per a "Handbook Of Operational Amplifier Active RC Networks" TI (actually Burr Brown) app note by Carter and Huelsman. Note that the mixing op amp has slightly different resistors from the higher bands to the virtual ground than the lower bands; this is needed to get the volumes of the different filters to match up.[[File:cgs serge resonant equalizer filter top and bottom filter bandwidths.jpg|thumb|center|300px|Note the top and bottom filter have bandwidths that are slightly wider than the rest.]]
 
== Construction ==