ST2 PRO: Next-Gen DSP Revolution in USB-C DAC HiFi Earphones

After phones dropped the 3.5mm jack, audiophiles had to carry a separate USB-C DAC dongle, one more thing to lose. Hidizs took the direct route: build the DAC amp into the earphone cable itself. ST2 PRO Nebula is a 2-in-1 product. The cable houses an ESS ES9218AC PRO DAC with DSP tuning and plugs straight into any USB-C phone, tablet or laptop. The earphones use a customized 10mm dual-magnetic dynamic driver with a PU+PEEK composite diaphragm, spanning 20Hz-40kHz with Hi-Res certification, tuned to Hidizs' own H-2019 curve. The clever part is that the cable itself is the product: delivering up to 70mW+70mW@32Ω, it detaches and pairs with any 0.78mm 2-pin or MMCX IEM, instantly converting older earphones into USB-C digital ones. In-line controls include an HD microphone, with zero-latency transmission aimed at gamers. Launched in December 2024, the campaign drew 3,183 backers and roughly HK$1.69 million (about $217K), some 4,230% funded.