ЦАПы — FiiO M33 R2R

The M33 R2R is a portable Android music player from FiiO that converts digital audio through a discrete resistor ladder rather than an off-the-shelf delta-sigma converter chip. It was presented around CES 2026, went on sale in China in January 2026 from CNY 3,999, and runs Android 13 on a Qualcomm Snapdragon 680 with 8 GB of RAM and 128 GB of internal storage, of which about 112 GB is usable. A microSD slot accepts cards up to 2 TB.

Key specs that matter

The 4.4 mm balanced jack delivers 1,100 mW per channel into 32 ohm (6 Vrms) in Super High Gain and 900 mW in High Gain, while into 300 ohm it gives 240 mW at 8.5 Vrms. The 3.5 mm single-ended jack provides up to 470 mW per channel into 32 ohm. FiiO lists 117 dB or better for SNR (A-weighted), a noise floor under 5.5 µV, THD+N of 0.0183% for PCM and 0.0033% for DSD, crosstalk of at least 74 dB and a 20 Hz to 40 kHz response. Local files play up to 384 kHz/32-bit and native DSD256, and in USB DAC mode the player accepts 768 kHz/32-bit and DSD512. The 5.5-inch laminated screen runs at 1080 x 2160, and the 4,400 mAh cell lasts about 13.5 hours balanced or 15.5 hours single-ended and recharges in roughly 1.5 hours. The body measures about 138.2 x 71.5 x 17 mm and weighs about 258 g.

Engineering and use context

The ladder is fully differential and 24-bit, built from 192 thin-film resistors across four channels - 48 per channel - with 0.1% tolerance and low temperature drift. Users can switch between oversampling (OS) and non-oversampling (NOS) operation. After conversion, two TI OPA1637 fully differential op-amps form the preamp stage, an NJW1195A chip sets the volume, and four INA1620 parts in parallel drive the headphones. The R2R array, preamp and output amplifier each get their own analogue supply, with partitioned shielding between the digital, ladder, amplifier and power blocks. Timing comes from an FPGA with two custom femtosecond oscillators, and an XMOS XU316 handles USB audio. Two Type-C ports allow a patented desktop mode that bypasses the battery, and connecting a fast charger unlocks the Super High Gain setting. Five operating modes are offered - Android, Pure Music, AirPlay, USB DAC and Bluetooth reception.

Pairing

Separate single-ended and balanced line outputs feed an external amplifier, and a coaxial output and USB audio pass digital signals to an outboard converter. Bluetooth 5.0 transmits in LDAC, LHDC, aptX HD, aptX and SBC and can receive LDAC. The matching RETRO BOX cassette-style Bluetooth speaker, with 5 W x 2 output, is sold separately.

Alternatives

The FiiO M23 is another portable Android music player from the brand, built around an AKM AK4191EQ and AK4499EX converter pair instead of a resistor ladder.