The FiiO KB3 has a built-in DAC and headphone amp. | Image: FiiOThe KB3 is a new mechanical keyboard from audio brand FiiO with a built-in headphone jack that stands a good chance of sounding better than the existing 3.5mm output on your desktop computer or laptop. That’s because the headphone jack isn’t just passing through a***og audio from your computer, it’s plugged into a combination DAC and headphone amp that’s integrated into the keyboard itself. So rather than having a headphone cable snaking across your desk to reach your machine, or cluttering up your workspace with a separate DAC and headphone amplifier, all these devices can theoretically be built right into the keyboard that’s sitting underneath your hands. And it comes from a company which knows a thing or two about audio (even if its…