Fets in distortion pedals

[RandomRedLetters]

is it possible to change transistors out from any normal OD pedal design (transistor, diode clipping type circuits) and replace them with FETs for a different sound. Of course rebiasing is needed, but is that it?

[rodriki1]

Hi

Some words sound wrong.

You CAN NOT change ANY transistor with fet.
Even fet with another fet sometimes.

We have infinite types of transistor with different atributes.

Fet have different type of operation from Bipolar Junction and high "resistance" (or impedance) at the input.

Sounds may change a lot.

Try to learn about transistor polarization scheme.

There are good references at web. Maybe a litlle boring for your taste
but if you are about it, the knowledge will be very useful.

Eletronics can be fun.

Regards

[davebungo]

You can't simply substitute in most cases as previously mentioned but with a few circuit adjustments and changes you would be able to substitute BJTs for FETs in most circuits.  It is obviously going to be much easier if you are at the breadboarding stage rather than trying to mod an existing pedal.  Many of the classic BJT "stages" (e.g. Emitter Follower) have equivalents in the FET world ( e.g. Source Follower) and have fairly similar characteristics.  This exercise does require knowledge of these fundamental things though so I wouldn't simply try to sub transistors without knowing what you are doing as you will no doubt end up frustrated.