The FiiO M33 R2R is a portable Hi-Res audio player that brings FiiO's self-developed, fully differential 24-bit R2R DAC architecture into a compact, mobile format for the first time. This technology combines the analog warmth of classic R2R converters with high resolution and precision. All of this results in a natural, detailed, and balanced sound at a reference level. The M33 R2R is powered by a Qualcomm Snapdragon 680 processor with 8 GB of RAM. It runs on Android 13 as its operating system. The internal storage of 128 GB can be expanded via a MicroSD card up to 2 TB. A dedicated XMOS XU316 USB chip ensures extremely low latency and perfect audio synchronization in USB DAC mode. The powerful headphone amplifier delivers up to 1100 mW + 1100 mW at 32 ohms (balanced) and effortlessly drives both sensitive in-ear monitors and demanding over-ear headphones. The 5.5-inch Full HD touchscreen display with durable Gorilla Glass 3 provides a clear representation, complemented by stylish displays such as a VU meter. Additional features include a 10-band PEQ with AUTO-EQ, dual USB-C ports with desktop mode, Bluetooth 5.0 with SBC/aptX/aptX HD/LHDC/LDAC, and a battery life of up to 15.5 hours. With 3.5 mm and 4.4 mm jacks that can function as either headphone or line-out, as well as coaxial SPDIF digital output and USB audio, the M33 R2R can be used flexibly in portable setups or integrated into stationary systems. In desktop mode, the battery is conserved while providing consistently high output power—ideal for use as a high-quality desktop DAC, headphone amplifier, or network streamer. Despite its extensive features, the FiiO M33 R2R remains pleasantly compact and comfortable to carry, weighing only about 258 g and featuring a slim design. A leather protective case and a hardened screen protector (pre-installed) are included in the package.