The original HiBy R6 Pro II was unusual for a mid-priced digital audio player. Its ambitious AKM decoding stage promised flagship-level conversion, but its relatively conservative headphone output prevented some demanding earphones from showing everything the DAC section could deliver.
The HiBy R6 Pro II 2025 Edition addresses that imbalance. HiBy has replaced the original AKM configuration with two Cirrus Logic CS4308P DAC chips, revised the amplification stage, and increased the 4.4mm balanced output to a claimed 632mW. The result is not merely a chip swap. The newer player sounds more controlled, more even-handed, and better prepared for IEMs and headphones that need additional current.
At the time of writing, the R6 Pro II 2025 is listed at $699 in black and blue at The HiFi Cat.
HiBy R6 Pro II 2025 Specifications
| Specification | HiBy R6 Pro II 2025 |
|---|---|
| DAC | Dual Cirrus Logic CS4308P |
| Processor | Qualcomm Snapdragon 665 |
| Operating system | Android 12 with system-wide SRC bypass |
| Memory and storage | 6GB RAM + 128GB internal storage |
| Maximum PCM support | Up to 32-bit/768kHz |
| Maximum DSD support | Native DSD512 |
| Amplification | Switchable Class A and Class AB |
| 4.4mm balanced output | Up to 632mW |
| Headphone/line outputs | Dedicated 3.5mm and 4.4mm PO/LO connections |
| Display | 5.9-inch, 2160 x 1080 |
| Battery | 5000mAh |
| Other functions | USB DAC, coaxial output, line output, two-way Bluetooth, HiByCast |
The specification sheet is competitive, but the most meaningful changes are the revised DAC implementation and stronger headphone output. They make the 2025 edition easier to recommend as a complete player rather than an excellent converter attached to an overly cautious amplifier.
Design and Daily Use
The R6 Pro II retains HiBy's distinctive asymmetrical chassis and curved back-panel design. It looks less conventional than many slab-shaped Android players, although the large 5.9-inch Full HD display keeps everyday navigation familiar.
The Snapdragon 665 and 6GB of RAM provide enough performance for music-library navigation, streaming applications, and general Android use. It is not intended to replace a current flagship smartphone, but it feels appropriately responsive for a dedicated audio player.
Android 12 also makes the R6 Pro II 2025 a practical choice for listeners who divide their time between a local microSD library and online services. HiBy's system-wide SRC bypass is important here: supported third-party applications can play without being forced through Android's standard sample-rate conversion.
The player can also serve several roles in a larger system. USB DAC support allows it to work with a computer or phone, while line output and coaxial output make it possible to connect an external amplifier or DAC. HiByCast adds remote control from a phone or tablet, which is particularly useful when the R6 Pro II is used as a desktop or home-system source.
Class A or Class AB?
The R6 Pro II 2025 includes separate Class A and Class AB amplification modes.
Class A mode is the better starting point when using less sensitive IEMs, full-size headphones, or recordings where density, control, and transient response matter most. It uses more power and produces more heat, but can give the presentation additional authority.
Class AB mode is more practical for sensitive IEMs and longer portable listening sessions. It reduces battery consumption and heat while retaining enough output for most everyday earphones.
The ability to switch modes is more useful than treating Class A as an automatic upgrade. With a sensitive IEM on a commute, Class AB may be the more sensible setting. At a desk with a more demanding load, Class A can take better advantage of the revised amplification stage.
HiBy R6 Pro II 2025 Sound
The overall tuning is balanced, clean, open, and controlled. It does not chase a heavily warm or bass-forward presentation. Instead, it prioritizes separation, transparency, and a stable soundstage.
The 2025 version has a firmer and more substantial presentation than the original R6 Pro II. Its stronger balanced output improves bass control and dynamic response, especially with earphones that did not sound fully energized from the older model.
Bass
Bass is controlled rather than exaggerated. Extension and texture are easier to notice than sheer quantity. With a neutral IEM, listeners should not expect the player to manufacture extra warmth or impact. With a fuller-sounding dynamic-driver IEM, however, the R6 Pro II preserves weight without allowing the low end to become loose.
This makes the player useful for buyers who prefer to choose bass quantity through their headphones rather than having it imposed by the source.
Midrange
The midrange is articulate and relatively uncolored. Vocals have clear outlines, good separation from accompanying instruments, and enough density to avoid sounding clinical. Female vocals can sound especially expressive with a smooth or mildly warm IEM.
Male vocals may appear leaner with strictly neutral earphones. Pairing therefore matters: the player works well with IEMs that add a little body through the lower midrange without obscuring detail.
Treble
Treble is clear, extended, and revealing. The player is capable of exposing fine recording detail and the leading edges of piano notes, strings, and percussion. With an already bright earphone, the combination can occasionally become slightly forward.
Listeners who are treble-sensitive should consider a neutral-warm or smooth IEM. Those who value openness and microdetail will probably appreciate the R6 Pro II's cleaner upper-frequency presentation.
Soundstage and Dynamics
The soundstage is open and well organized, with good lateral width and convincing depth when the recording contains it. More importantly, instruments remain separated when arrangements become busy.
The improved amplification gives the 2025 edition faster and more confident dynamic swings. Orchestral passages, live jazz, and rhythmically complex recordings sound less compressed than they can through a lower-powered source. It is not only louder; the presentation feels more stable as the music becomes demanding.
Earphone Pairing Notes
Etymotic ER4SR: Neutral and Highly Revealing
The ER4SR emphasizes the R6 Pro II's transparent and controlled side. The combination delivers precise imaging, clean vocal articulation, and low coloration. It works particularly well for female vocals, acoustic recordings, chamber music, and listeners who value accuracy.
The trade-off is bass weight. Neither component is designed to add generous low-frequency warmth, so electronic music and bass-heavy pop can sound lean. The ER4SR also uses a 3.5mm connection, which cannot take advantage of the player's full balanced-output capability.
Best for: vocal detail, acoustic music, chamber music, analytical listening
Less ideal for: listeners seeking thick male vocals or powerful sub-bass
JVC HA-FW1800: More Body and Space
The JVC's wood-diaphragm dynamic driver gives the pairing more tonal body while preserving the player's spacious and detailed character. Vocals sound smoother, the stage feels relaxed, and bass instruments gain greater weight than they do with a strict reference IEM.
Piano can occasionally sound a little bright, depending on the recording, but jazz benefits from the combination's separation and rhythmic stability. The R6 Pro II helps keep instruments distinct while the JVC adds a more organic texture.
Best for: Japanese pop, vocals, jazz, listeners wanting a fuller dynamic-driver sound
Watch for: bright piano recordings or listeners highly sensitive to upper-midrange energy
HiBy Project ACE-JP: Fine Detail and Vocal Texture
The Project ACE-JP highlights microdynamics and gives vocals a slightly warmer, more intimate character. Its titanium-diaphragm presentation adds a distinctive metallic clarity without turning every note sharp.
Female vocals are a particular strength. Piano has good density and a clearly defined shape, while small-ensemble recordings retain separation and atmosphere. Bass quantity is sufficient, although listeners who prioritize maximum low-frequency grip may want an IEM with tighter bass control.
Best for: female vocals, detailed pop, small ensembles, listeners who enjoy textured mids
Watch for: buyers who want the most tightly focused bass response
General Pairing Advice
The R6 Pro II 2025 is easiest to match with an IEM that is neutral to mildly warm, capable of good detail without an aggressive treble peak, able to benefit from the 4.4mm balanced output, and not excessively bass-light.
Bright, lean earphones can make the system sound more analytical than some listeners prefer. Warm dynamic-driver or well-balanced hybrid IEMs often create a more versatile combination.
Compared with a Warmer R2R Player
Compared with a similarly priced R2R-based player, the R6 Pro II 2025 takes the cleaner and more technically explicit approach.
The warmer R2R presentation can make older pop recordings sound rich, relaxed, and forgiving. It softens hard edges and places greater emphasis on atmosphere. The compromise is that fine detail, separation, and rapid dynamic changes may sound less sharply defined during complex orchestral or live recordings.
The R6 Pro II 2025 sounds more open, precise, and responsive. Its vocal images are less forward and less thick, but outlines are clearer and low-level information is easier to follow. It also handles large dynamic changes with greater confidence.
Neither approach is universally better:
- Choose a warmer R2R player if you prioritize relaxed tone, older recordings, and long fatigue-free sessions.
- Choose the R6 Pro II 2025 if you prioritize resolution, separation, soundstage organization, and broader genre compatibility.
What Changed from the Original R6 Pro II?
The original R6 Pro II used an AK4191EQ plus dual AK4499EX DAC configuration. The 2025 edition moves to dual CS4308P DACs and revises the output stage.
The practical differences are more important than the chip names:
- More balanced-output power: the 4.4mm output reaches a claimed 632mW.
- Better control: bass, transients, and demanding passages sound more stable.
- A more even tonal balance: the 2025 edition is less overtly dramatic and easier to match.
- Improved compatibility: lower-sensitivity IEMs and moderately demanding headphones benefit more from the new amplification stage.
Owners of the original version who mainly use sensitive IEMs may not need to upgrade immediately. Buyers who found the first model underpowered, or who regularly use the balanced output with harder-to-drive earphones, have a stronger reason to consider the 2025 edition.
Who Should Buy the HiBy R6 Pro II 2025?
The R6 Pro II 2025 is a strong choice for:
- listeners who want open Android streaming and local-file playback in one device;
- owners of good IEMs who need more power than an entry-level DAP provides;
- buyers who value separation, clarity, and soundstage over exaggerated warmth;
- users who want both 3.5mm and 4.4mm headphone and line outputs;
- listeners who may also use the player as a USB DAC, digital transport, or desktop source.
It may be less suitable for:
- buyers who want the smallest and lightest possible music player;
- listeners seeking a strongly warm, thick, or bass-enhanced source;
- users who only listen through Bluetooth earbuds and do not need its wired-audio hardware;
- owners of extremely demanding full-size headphones that would be better served by a dedicated desktop amplifier.
Final Verdict
The HiBy R6 Pro II 2025 is a more complete product than the original model. The move to dual CS4308P DACs is noteworthy, but the stronger and better-balanced amplification stage is the change that matters most in daily listening.
Its sound is clean, spacious, detailed, and controlled. It can reveal weak recordings and may sound slightly bright with an already forward earphone, but thoughtful matching produces a system with excellent separation, fine microdetail, and convincing dynamics.
For buyers looking for an Android digital audio player around the $700 level, the R6 Pro II 2025 offers a useful middle ground between affordable portable players and far more expensive flagships. It has enough power and connectivity to grow with a serious IEM collection, while remaining flexible enough for streaming, local playback, and desktop use.
Current listed price: $699
Available colors: Black and blue
Purchase: Shop the HiBy R6 Pro II 2025 at The HiFi Cat
Frequently Asked Questions
Is the HiBy R6 Pro II 2025 good for streaming?
Yes. It runs Android 12 and supports third-party music applications. HiBy's system-wide SRC bypass is designed to preserve the original sample rate from compatible playback and streaming apps.
Does the R6 Pro II 2025 support balanced headphones?
Yes. It has a dedicated 4.4mm balanced headphone output and line output. The balanced headphone output is rated at up to 632mW.
What is the difference between Class A and Class AB mode?
Class A prioritizes drive, density, and transient performance but uses more battery and produces more heat. Class AB is more efficient and is suitable for most sensitive IEMs and longer portable sessions.
Can the R6 Pro II 2025 drive full-size headphones?
It can drive many portable and moderately demanding full-size headphones, particularly from the 4.4mm balanced output. Very inefficient planar headphones or high-impedance models may still benefit from a dedicated desktop amplifier.
Is the 2025 version better than the original R6 Pro II?
The 2025 model offers substantially more balanced-output power and a more controlled, versatile presentation. Whether it is a necessary upgrade depends on the earphones you use, but it is the easier version to recommend to a new buyer.
Does it support high-resolution audio?
Yes. The player supports PCM up to 32-bit/768kHz and native DSD512.
Editorial note: Sound descriptions are subjective and depend on earphones, recordings, gain, amplification mode, and listening volume. The listening observations in this article were independently rewritten and contextualized from the published listening report by KM.Lau, combined with current specifications from The HiFi Cat's product listing.
Source article: KM.Lau's Chinese listening report
