OVERDRIVE TYPES- Noninverting OpAmps, MOSFETS and JFETs ...the Big 3 ...which is your sound?

OVERDRIVE TYPES

NON INVERTING OpAmps

These pedals create Symmetrical Distortion. These pedals are popular for low gain and transparent sounds as they boost the 'even order harmonics which are tightly related to the notes and chords going through them. A Fuzz is all about odd order harmonics which are the harmonics which are less musically related. In an acoustic guitar they add character but are very subdued. So pedals made with these OpAmps are more natural sounding but not at all tube amp sounding. Basically we are talking about a Tube Screamer and the beefed hundreds of super tweaked variations.

MOSFETS

They are very tube like, and like a tube the more you stack one on the other in a row the more dirt you create. Like tubes they create a mix of odd and even order harmonics so they create asymmetrical distortion.

JFETS

They are the same as MOSFETS except when hit hard they gasp and rasp a bit. Where as the MOSFETS are more warm and sweet the JFETS are a bit angry and in your face.

SUMMARY

Non Inverting OpAmps are virtually Tube Screamers. 

Mosfets and J-Fets are the various amp-in-a-Box pedals. All the hot big selling Overdrives are one of these.