LADDER Schumann R2R DAC HIFI USB DSP Coaxial OPT AES Resolution Audio DecoderAfter 3 years of research and development going through repeated engineering debugging Create a high resolution audio dac: Ladder Schumann. The DAC using DSP processing and usb interface decoding scheme based on FPGA decoding architecture. Ladder Schumann R2R digital to analog converter network which uses the FPGA chip that intel Altera cyclone version 4 that is a chip that you know field programmable gate array which is basically digital chip that