[sdiy] Ray Wilson Filter question

[harrybissell]

well OK I'd change this thought...


> --Put a 1K resistor in between the - input of the OTA and ground...right
> now, as Ray did it, this signal goes straight to ground. This 1K
> additional resistor guarantees that the current added with the mod doesn't
> go straight to ground, but instead goes into the - input as desired.
>

The additional resistor forms two things... one is that the resistance from each
input of the OTA to ground is 1K.  This balance will help offset voltage in the
first place.  Two is that the 1M / 1K make a huge voltage divider, dropping the DC
level down to useful levels...  like about +/-15mV at the inverting input.

But hookup-wise you are golden !

H^) harry