Old Crow Shruthi CS-80 Filter - Modular Addict Synth-DIY
Amazon.com: BPF Filter Module, PCB Filter Board, Electronic Filter Components, Center Frequency 433 MHz, ‑40℃‑70℃, Strong and Durable, Integral Molding Has No Burrs : Electronics
Designing PCB Filters using MATLAB
DIRT Filter Eurorack PCB & Panel from Synthrotek on Tindie
Power Supply Filter Design for PCB | Tempo Automation