FiiO M25 specifications revealed

The FiiO M25 is approaching its official launch, and part of its specifications were revealed over the past weekend. Several images of the M25 were also published on social media, showcasing the design of the DAP (Digital Audio Player). In addition, early impressions regarding the sound performance of FiiO’s new “sub-flagship” DAP have surfaced. Below are all the details currently available regarding this upcoming release.

Update (August 1): The expected launch timeline for the FiiO M25 has been updated in the “Launch, Price, and Availability” section.

M25 is the first FiiO DAP to launch simultaneously in two versions

The successor to the FiiO M15S, the M25 will be released by FiiO in two distinct DAC configurations: one based on Delta-Sigma architecture and another utilizing R2R technology. FiiO CEO and founder James Chung stated:

“This is the first time in FiiO’s history that the same model is being mass-produced and launched simultaneously with two different DAC versions, in the hope of providing users with more options.”

The M25’s “R2R PRO” DAC and the naming of the different M25 versions

The R2R DAC was developed internally by FiiO, and the implementation used in the M25 is more advanced than that found in the FiiO K11 R2R and FiiO K13 R2R. For this reason, the company refers to the DAP as the “M25 R2R PRO.” In the case of the “M25 VERITA,” the device utilizes the AK4499 DAC chip manufactured by Asahi Kasei Microdevices (AKM), the Japanese DAC manufacturer.

FiiO CEO James explained the differences between the two M25 versions as follows:

“The version featuring a traditional integrated DAC uses AKM’s flagship AK4499 DAC, while the in-house developed R2R version adopts FiiO’s proprietary segmented R2R ladder decoding technology based on thermal coding. To distinguish it from the R2R technology used in the FiiO K11 R2R and FiiO K13 R2R, we named it ‘R2R PRO.’ It utilizes nearly 400 high-precision, low-temperature-drift resistors.”

The purpose behind launching two M25 versions

According to FiiO CEO James, the M25 will be released in two DAC configurations in order to deliver distinct sonic characteristics.

While the M25 VERITA, which uses the AKM AK4499 DAC, promises “maximum sonic fidelity,” the M25 R2R PRO is said to deliver “a warmer timbre focused on vocal presentation.”

How the two M25 versions sound

According to the Weibo user “Earphone Aesthetics,” the sonic characteristics of the two M25 versions are as follows:

“In terms of sound, the M25 offers two decoding versions: one featuring a dual AK4499EX + AK4191 configuration, and another based on R2R technology. In practice, both are highly engaging and deliver a relatively similar soundstage scale, sharing an overall sonic framework that is quite alike. The differences mainly lie in the details across the three frequency ranges and in the way the sound is refined.

The AKM DAC version presents more delicate and fuller mids and highs, along with slightly more bass reverberation, creating a more atmospheric presentation overall. Meanwhile, the R2R version delivers even more refined treble, with better-defined note outlines, as well as greater sound density and a more textured presentation. However, both versions follow a tuning approach aimed at popular music genres, with a strong emphasis on musicality.”

Battery capacity larger than the M33

While the FiiO M33 features a 4400mAh battery, the M25 is equipped with a 6500mAh battery. So far, no information has been disclosed regarding the battery life of either the M25 VERITA or the M25 R2R PRO.

FiiO M25: Partial specifications

• Battery capacity: 6500mAh
• Chassis material: aluminum alloy
• Colors: Glossy black and matte silver/white
• DAC chip in the M25 VERITA: 2 × AKM AK4499EX
• DAC implementation in the M25 R2R PRO: in-house developed R2R PRO DAC by FiiO
• Display: 5.5-inch screen with 1080 × 2160 resolution
• Equalization support: 31-band PEQ + AUTO EQ
• High-capacity FPGA chip + custom femtosecond crystal oscillator developed by FiiO
• Internal storage (ROM): 128 GB
• Maximum output power: 1700mW
• RAM: 8 GB
• SoC: Qualcomm Snapdragon 778G with QCS6490 architecture
• USB controller chip: XMOS XU316

Launch date, pricing, and availability

The FiiO M25 R2R is scheduled to launch in September 2026. However, the price of the M25 has not yet been announced, and it is still unclear whether the M25 VERITA will be priced the same as the M25 R2R Pro.

Why the M25 Launch Was Delayed

FiiO originally planned to release the M25 in July 2026, as previously reported by Hi-Fi Hub. However, due to component shortages and the need for further refinements, the launch date was postponed.

On June 25, FiiO staff member Matt explained that the delay was caused by component shortages and the need for additional tuning.

“After several trade shows and internal evaluations with members of the press, the sound tuning of both the M25 and the M25 R2R still requires further refinement. In addition, with the PCB mass-production lead time now at two and a half months, it is highly likely that the M25 will not be released until September.”

One week later, on July 2, FiiO founder and CEO James Chung provided further details, explaining that the company was facing a shortage of PCB boards.

“At present, not only have PCB prices increased significantly, but lead times have also become much longer. The M25 uses HDI (High-Density Interconnect) PCBs, the same type used in AI servers and other artificial intelligence hardware. The current lead time for these boards has already exceeded 75 days, more than two and a half months. We appreciate everyone’s understanding.”

Below is a short video of the FiiO M25 published by the Weibo user “Earphone Aesthetics.”