[sdiy] linearize OTA for VCF?

[jhaible at t-online.de]

>     Hmm....I used current sources to run the diodes on a 
> 13700 and I thought I 
> didn't have any problem...maybe I better go back and take 
> a look. 

Which resistors did you replace ?
Replacing *all* resistors with current sources *must* work.
Replacing the two resistors to GND (lowest value, thus
least ideal current source approximation) with current 
sources shows the mentioned, undesired effect.

JH.