In this livestream I put the Fosi Audio DS3 on the desk and walk through what it actually does in real listening—no spec-bloat, no hype. It’s a tiny little USB DAC/amp (seriously, 16g) built around the ESS ES9039Q2M, with both 3.5mm single-ended and 4.4mm balanced out. The big question for me was simple: does it sound clean and natural for IEMs and portable headphones at around $130, or is it just another “good on paper” dongle-style box? I also dig into the weird part: the dual USB modes. The DS3 lets you switch between UAC 2.0 for HiFi and UAC 1.0 for “gaming,” and I talk about why that’s even a thing, what it changes in day-to-day use, and who it might help. On top of that, I touch on the ESS digital filters (eight of them) and how I think about filters in general: they’re fine to experiment with, but I’m listening for tone, timbre, and whether the presentation stays grounded. Takeaway: the DS3 is aiming for clean power and a refined, non-fatiguing listen—just don’t buy it for the modes alone without understanding what they’re doing.