The sound quality is determined by the output sample rate/bit depth and the DAC quality. Dragonfly red is the USB DAC and supports up to 24-bit/96 kHz. Compared this setup with the WiiM Mini with an external DAC via Optical port, WiiM Mini could support up to 24-bit/192 kHz output (with the latest firmware version). If the connected DAC quality is good, it can provide similar or better sound quality.