This project is a simple adapter board for adapting the INA1620 opamp to the pinout used by the OPA1688 opamp. I made this project as a modification to my Topping NX4 DSD portable headphone amplifier, since the INA1620 is a technically superior opamp that looks to be a suitable upgrade over the OPA1688 opamps in the final amplification stage of the NX4.
The PCB design essentially matches up the pinout of the OPA1688 to the equivalent pins on the INA1620, with a couple of 0.1uF capacitors added between GND and the voltage rails for the purpose of noise surpression, as suggested by the application notes for the INA1620 from Texas Instruments.
3/22/20: Final design complete. Prototype PCBs ordered from OSH Park, stencils ordered from OSH Stencils
