> > If the 12KHz band actually has the lowest amplitude of any of the bands, I > would invert the signal with an op amp configured as an inverting > amplifier > and then apply it to the LM567s. This would then give the 12KHz band the > highest amplitude, otherwise, I would proceed with Jim's recommendations. > > You're kidding... Right? -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.