Pitch shiftergit

Pitch Shifter:

System Overview A frequency-tracking pitch shifter The design avoids digital DSP in favor of a CD4046 Phase-Locked Loop (PLL) and CD4017 decade counter for interval sequencing.

im very connected to music and rock culture, and its all started when i talked with my friend about how expansive effect pedal are. and then i thought, maybe i can build one, so from there i searched for like a month on how to buld them, about the electronics of the audio, and the logic. and i asked myself how can i make it. and then i found kicad as almost the only free softwere that worked for me, and i learned how to use it, this project has alot of versions some of them are really bad, but thats how i learned to design a pcb.

the pcb design: this pcb design had a lot of changes, at first i had a 2 layers board, unorgenised and to big to be in the enclouser, and then i made it smaller, changed some foorpeint, rerouthed the pcb, added fillings, and i almost sent it for prodaction like that. and then i felt that something is misssing, and that i wanted to create a intresting pedal that will be good and easy, so in this version i addad relay switch to create a bypass and added caps and, more diods, and resistors to protect the parts from overload, backcurent, and stuff that willl ruin the board. and i changed the board size and redone the traces again to finaly fit my expactation and the enclouser.

the leyers of the pcb:

the circuit: The circuit takes an audio, signal shifts its pitch down and outputs it with 5 selectable pitch steps controlled by a push button. The core chips are a CD4046 (handles the pitch shifting) and a CD4017 counter (steps through the 5 settings). A TL072 op-amp buffers the input signal, and five NSL-32 optocouplers that i swiched to VTL5C4 in prodaction becouse of avilablity. this optocouplers (optical) do the switching between pitch steps without noise, becouse there is not current passing between them.

logic schematics:

audio schematics:

the battery compartment: i sd designed a 9v battary compartment in solidworks that will fit exactly in the enclouser

assembly: i also created a 3d assambly of the pedal in solidworks, the assembly is partial becouse it would take me a lot of time to do every thing and its mainly for fitting and concepts. but the main parts are in there.

Technical Specifications:

Frequency Synthesis: CD4046 PLL tracks input frequency; CD4017 logic handles interval division/multiplication. Analog Interface: VTL5C4 Vactrols integrated for smooth interval transitions. Calibration: 5x 50k trimmers for precise frequency offset tuning. Input Stage: TL072 op-amp buffer for high-impedance guitar signal integrity. Bypass: Relay-based switching system for transparent operation.