TPA6120 Portable Headphone Amplifier V3.0

Version update history:
V1.0-->First version, only includes the 6120 headphone amplifier and power supply (serious problems exist)
V1.1-->Added 2706 USB interface, 1754DAC, and audio source switching circuit (still has serious problems, this The plan has been scrapped)
V3.0 (pre-release) --> Cut off the low-performance USB decoding part, optimize the circuit design, and reduce the size. It is currently being produced. I hope it will not overturn.
Introduction
       This is a USB-powered Desktop headphone amp, compact in size, easy to carry and store. The headphone amplifier chip is TPA6120A2, the input buffer operational amplifier is NJM4580,
the TPS65131 is used to generate positive and negative 12V power supplies, and an 8-pin potentiometer is used for switching on and off and adjusting the volume, which can drive headphones with an impedance of 16Ω~600Ω.
V3.0 PCB design drawing, the PCB size is reduced from the previous generation’s 80*50 to 60*40 (the extra 1.6mm on each side is used to fit into the 60*19*46 casing. The
matching front and rear panels are currently being designed Center)
3D simulation diagram:
physical display part
(to be added)