FXBus 1 Module 2 - a JFET Mu-Amp Module

Copyright 2000 R.G. Keen. All rights reserved.

In contrast to Module 1, Module 2 has many fewer options. It's intended for one thing only - to get high gain from a pair of JFETs. This basic circuit was known from the days of tubes, when it was built from triodes, and was published by National Semiconductor in a JFET application note. Recently, it has been popularized by Jack Orman for guitar effects use as the "Mini-Booster".

The schematic is shown on Jack's site at http://www.muzique.com/amz, and the parts designations match the ones in that schematic.




About the only options beyond component values to deal with here are:

Conventional wisdom is that J201 JFETs sound best in this circuit. Watch the pinouts - it's laid out for the J201, but some other JFETs have DGS in stead of DSG pinouts; solder accordingly!