Quality through-hole JFETs are becoming hard to find, replacing them with their SMD version is the best solution. This PCB is designed for placing JFET SMD transistors and easily substituting the through-hole ones in your circuit. PCB   https://www.taydaelectronics.com/smd-toto-92-diy-pcb-guitar-effect.html The PCB is marked with D (Drain), S (Source) and G (Gate).   The PCB is designed for J201, 2N5457, 2N5458, MPF102... with the pinout as shown in the following figure. If you want to use other types of transistors, please check the pinout in their datasheet. ASSEMBLINGpcb Add a small amount of solder on each pad of the PCB.Place the transistor over the pads with the tweezers. Melt the solder on the PCB pads and the transistor legs. You can use pin headers (40 PIN 2.54MM RIGHT ANGLE SINGLE ROW PIN HEADER) or wires to connect the PCB to your effect circuit. The pin headers can be assembled on both sides of the PCB, depending on the available room that you have around the transistor on the effect PCB.          Once the transistor and the pin headers have been placed, you can place the PCB on the original through-hole footprint.