A USB-powered, battery-assisted portable DAC/amp, $229 from Qudelix, built around four ESS ES9219C chips and two TI INA1620 op-amps. Sources agree most on its feature set: a 20-band parametric EQ per channel, stored on the device, 7.1-channel input with a downmix to headphones, three headphone jacks and an information-rich screen. Nothing else at its size offers the same combination, though it has no Bluetooth and no pass-through charging. On the bench it is close to desktop-class (SINAD 110 dB, 8 V balanced). Most listeners call it transparent, and a minority hear it as flat or lacking depth. Opinion splits along clear lines elsewhere. Its high voltage suits high-impedance headphones, but current limits it on low-impedance planars. Noise is fine for most IEMs, but a few owners hear hiss with ultra-sensitive sets or radio interference next to a phone. Many owners find the interface and app hard work. A handful of owners report failed units. And whether it is worth $229 depends on using the DSP, 7.1 input or extra power; for plain stereo, several sources point to the 5K.
About this product
The USB-only DAC/amp (Qudelix writes it “Qudelix-T71”). Not the Bluetooth Qudelix-5K, and not the “T71 IEM”, a companion in-ear that plugs into the T71’s second USB-C port and works only with it.
Qudelix built its name on the 5K, a thumb-sized Bluetooth DAC/amp with an unusually deep EQ app. The T71, launched in mid-2023, is its bigger, wired-only sibling: a 75-gram aluminium box with four ESS DAC chips, a small colour screen, 3.5, 2.5 and 4.4 mm outputs, up to 8 volts balanced, and a USB input that accepts up to eight channels, so games, films and Atmos music can be folded down to headphones.
For two years it was a niche device discussed mostly by the people who owned one, until Audio Science Review's bench test at the end of 2025 put it among the best-measuring portables. The arguments are rarely about whether it performs. They are about who it is for: whether its power holds up on low-impedance planars, whether the app-driven interface is worth learning, and whether a stereo-only listener gains anything over the far cheaper 5K.
