FIIO M25 (AKM) & M25 R2R
FIIO’s new M25 takes an unusual approach to the high-end portable player market. Rather than offering one DAC architecture as the premium option, the company sells two parallel versions — M25 and M25 R2R — at the same price.
One uses a flagship AKM delta-sigma DAC configuration, while the other features FIIO’s own discrete R2R ladder design. The rest of the platform is largely shared, turning the choice into one of sonic philosophy rather than product hierarchy.
In Japan, both models are priced at around ¥220,000 and will go on sale on October 23, 2026.
AKM VERITA or FIIO R2R PRO
The standard M25 uses an AK4191EQ digital processor with two AK4499EX DAC chips, with one DAC assigned to each channel.
This configuration follows AKM’s flagship VERITA architecture, separating digital processing from analogue conversion in an effort to improve channel separation and reduce interference.
The M25 R2R, meanwhile, uses FIIO’s own 24+5-bit segmented R2R PRO ladder DAC.
The upper five bits are handled by 31 thermometer-coded resistor elements, an approach intended to reduce switching errors and non-linearity that can occur in conventional ladder architectures.
FIIO positions the two versions differently rather than describing one as superior. The AKM model is presented as the more precise and contemporary-sounding option, while the R2R version is tuned toward a smoother and more natural presentation.
Those descriptions are manufacturer voicing claims, of course, and actual differences will depend on headphones, source material and listener preference.
The R2R model also allows users to select OS and NOS modes, while the AKM version provides its own digital filter and sound-tuning options.
Desktop-Level Power in a Portable Player
Beyond the DAC section, the two M25 models share most of their hardware.
At the centre is Qualcomm’s QCS6490 platform, paired with 8GB of RAM and 128GB of internal storage. A microSD slot allows users to expand their local music library, while the Android-based operating system supports streaming apps directly on the device.
The analogue output stage is fully differential, with the 4.4mm balanced output capable of delivering up to 1,700mW + 1,700mW into 32 ohms.
A 3.5mm single-ended output is also included.
FIIO has also designed the M25 to work as a desktop component. In Desktop Mode, the player can operate from external power while bypassing the battery charging path, reducing unnecessary battery cycling during long listening sessions.
USB DAC duties are handled by an XMOS XU316 interface.
31-Band PEQ and Auto EQ
Software-based tuning is another major part of the M25 platform.
Both versions support 31-band parametric EQ as well as Auto EQ, allowing users to adjust headphone or IEM response in considerable detail.
FIIO has been steadily expanding PEQ support across its desktop and portable products, and the M25 continues that trend.
Network connectivity includes Wi-Fi and AirPlay, while Bluetooth 5.2 is available for wireless audio.
The display is a 5.5-inch 1080 × 2160 panel, and the player weighs approximately 318g.
R2R Lasts Longer on Battery
One surprising difference between the two models is battery life.
According to FIIO, the standard AKM M25 offers around 9.5 hours of single-ended playback, while the M25 R2R extends that figure to approximately 14.5 hours.
That may seem counter-intuitive given the reputation of R2R architectures for relatively high power consumption, but the final result depends on the complete implementation rather than the DAC topology alone.
Actual battery life will vary with screen brightness, output level, network use and file format.
Same Price, Different DAC Philosophy
Perhaps the most interesting part of the M25 project is the pricing strategy.
R2R variants are often positioned as more expensive specialist models, while delta-sigma versions occupy the mainstream slot. FIIO has avoided that distinction entirely.
Both the M25 and M25 R2R are priced at 7,499 yuan in China, with the Japanese market price set at around ¥220,000 for either version.
That effectively turns the buying decision into a direct choice between two conversion philosophies.
Listeners can choose the flagship AKM architecture with its digital processing flexibility, or FIIO’s own R2R implementation with OS/NOS operation and a different tuning approach — without paying a premium for either.
In that sense, the M25 is less about proving whether AKM or R2R is objectively better and more about giving users the opportunity to decide which approach suits them.
Key Specifications
| M25 | M25 R2R | |
|---|---|---|
| DAC | AK4191EQ + AK4499EX ×2 | FIIO 24+5-bit R2R PRO |
| DAC architecture | Delta-sigma | Resistor ladder |
| OS / NOS | No | Yes |
| Processor | Qualcomm QCS6490 | Same |
| RAM / Storage | 8GB / 128GB | Same |
| Display | 5.5-inch, 1080 × 2160 | Same |
| Outputs | 3.5mm / 4.4mm | Same |
| Max balanced output | 1,700mW + 1,700mW / 32Ω | Same |
| USB DAC | XMOS XU316 | Same |
| EQ | 31-band PEQ / Auto EQ | Same |
| Network | Wi-Fi / AirPlay | Same |
| Bluetooth | 5.2 | Same |
| Battery life | Approx. 9.5 hours | Approx. 14.5 hours |
| Weight | Approx. 318g | Approx. 318g |
| Japan price | Approx. ¥220,000 | Approx. ¥220,000 |
| Japan availability | October 23, 2026 | October 23, 2026 |
Source : FIIO https://www.fiio.com/M25
