Re: J201 and 2n5457 replacements

Posted by Frank_NH on Oct 05, 2015; 2:03pm
URL: http://guitar-fx-layouts.238.s1.nabble.com/J201-and-2n5457-replacements-tp24940p24974.html

- Did anyone already did a pedal that is basically just the Fetzer Valve to hear how it sounds?

Here's a vero for you.  Should sound like a nice booster with some crunch (depending on your jfet).

Marsha Valve

- Should I measure the FETs and change the bias resistor on pedals that use them?

For pedals where the drain resistor is fixed (such as the original Wampler Plexidrive), yes you should measure the JFETs to see if the fixed drain resistor value is appropriate.  However, most effects that use JFET stages have trimmer pots for the drain resistors to avoid this problem.  You can then stick in any JFET you want and adjust the trimmer to achieve the proper bias at the drain (usually around 1/2 the supply voltage).