Let me recommend this excellent paper on opamp distortion. It contains actual measurements of many chips that have been used in pedals, though it is more applicable to high-end audio applications. It’s a big file to download but if you are interested in this subject, it is well worth a look. Nice work, Samuel!
I was hoping some of the Burr-Brown TI OAs would be in the paper (not that I use those for distortion). Are any of these amps *good* for distortion? And does the data give clues as to why? Basically I got from this paper that $4 are better than $.99 ones for audio purposes 😉 I’ll have to print the PDF and leave it in the bathroom for pondering!
Thanks for the link!