[baylessj]

Excellent writeup, I love seeing real engineering applied to guitar pedals rather than black magic tone chasing.

I'd be really curious to see if the model could be expressed as a transfer function and compared to the schematic for the pedal. The Tubescreamer is a fairly simple circuit but the mystery surrounding it indicates that there are some weird variables at play with the component properties that would lead to additional factors in the transfer function. Wonder if those variables could be identified somehow.

[hashkb]

The "weird variables" may have to do with the various changes in manufacturing over the years. "Tube screamer" refers to at least 10 different units. Maxon, Ibanez, TS9, TS808, and zillions of clones.