I’m blocked from modifying the Flux project right now because execution credits are unavailable, so I have not added components, wiring, or layout yet.
Recommended schematic direction for your Jerry Garcia-style guitar JFET buffer:
Power: 9 V battery input with nets labeled V+ and V-
Signal I/O: high-impedance Input and low-impedance Output
Core circuit: single JFET source follower buffer, similar to classic onboard guitar unity-gain buffers
Likely topology:
JFET drain to V+
JFET source through resistor to V-
Gate biased with large-value resistor to V-
Input coupling/protection as needed
Output AC-coupled from source
Connectors: 4 external pads or header pins:
V+
V-
Input
Output
PCB goal: small guitar-cavity-friendly board, likely around 0.75 in × 0.5 in or smaller depending on through-hole vs SMD parts.
What remains to be done when execution is available:
Rename the project from the placeholder name.
Choose the exact JFET, preferably a low-noise audio JFET such as J201, 2N5457, or an available SMD equivalent.
Verify the JFET datasheet pinout and bias requirements.
Add the JFET, resistors, capacitors, battery/input/output pads, and optional power filtering.
Wire the schematic with nets named V+, V-, Input, and Output.
Run electrical review and fix any violations.
Size the PCB for guitar installation.
Place parts compactly and route the board.
Once credits are available, I can build the schematic and PCB directly in the project.