GC_ET_AFX_HPM.html
161117-0836
2021-01-06   11:53:00 

             "HiPerMite Audio Filter"

Above is the HiPerMite 2015 Kit assembled.
Stages in the HPM are Lo,Lo,Lo,Hi pass.
Stages here are VCVS topology ,  
and produce a pronounced 'Band Pass" Butterworth shape . 

HPM designer Cripe used the VCVS circuit design, which works well. 
F(center) is adjusted by adjusting hard-ware components.  No Single f() control. 
 

Precision components required.    Difficult to adjust for component variations.  
Be sure to trim and pad resistors to 1% and use precision caps.  

*** This Bode is from WE8DSB 

   

This Bode is from QRQ-CW.net, showing the depth of the filter action.  
 

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"Original" Hi-Per-Mite article from a 1994 magazine, original 12 chip layout. 

*** 1994 Original Active circuit Schematic.

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