[sdiy] linearize OTA for VCF?

[Terry Michaels]

Message text written by "Ian Fritz"
>Hi --

Looking through my vcf schematic collection, I notice that none of the
designs use the linearizing diodes on the OTA inputs. Does anyone have any
comments on the pros and cons of using these, and has anyone actually
incorporated them in a design?

Best regards,

  Ian<

Hi Ian:

Consider this:  Non-linearity in a low pass filter isn't necessarily all
that bad, the filter cutoff will usually attenuate many of the harmonics
created by the non-linearity, especially the higher harmonics, which are
harsher.  OTOH, if I was designing a high pass filter, I would make that as
linear as possible, that's a case where the harmonics created by
non-linearity are more objectionable and noticeable.

Terry Michaels