JFET preamp

A preamplifier with Junction Field Effect Transistor (JFET) makes your guitar sounds great, operating in similar manner to the vacuum tubes. This circuit is very simple to build and can be used as a booster.

Created by DHEA
Status: Active

Enclosure and wiring Step 5 of 5


You should install all the parts (DC and 3.5 jack connectors, 9V battery clip, 3PDT foot switch, assembled PCB...) in the enclosure. The led diode and its holder can be placed where you want. The round side and longest leg is the anode (marked as a square pad in the PCB). It is possible that you need to remove the little metal tag from the potentiometers to easily install them in the enclosure.


You can create your own element distribution and use many types of enclosures. It is recommended to use a metal enclosure and connect it to the ground in order to attenuate the noise (normally the GND of tthe input and output jacks are in contact with the enclosure). For this project, you can use the 1590A or 1590B enclosures. If you use the 1590B, it will be easier and you will be able to install a 9V battery inside the pedal. Bellow find some examples that you can take as reference. After the drilling, you can paint and decorate the enclosure as you desire. Finally, install all the elements and you can beguin with the wiring.



For the wiring you should use 24 AWG stranded wire. Wire all the elements as indicated in the following diagram, for the ground (GND) no mater the order you use if all the elements are connected.You can power up the circuit with DC adapter (9V) or a battery. The diagram shows the connections to use the DC connector as negative tip (standardized Boss style 2.1 mm with a negative tip orientation).


You can also use the PCB for 3PDT footswitch. It will help you to wire all the components, keep a neat circuit and reduce the noise. The PCB also includes pads for the led and its current limiter resistor.