I recently bought the R3 II (it has some features that I don't really like but it works perfectly fine), and i recently saw the R4 and I fell in love with the design, however I don't want to buy it and leave my R3 to find it's not much of an upgrade so what are the advantages over the R3 (sonically speaking) apart from Android system, is it worth the upgrade?

Rn I'm using the R3 with the Fiio JH5, JH3 and the EPZ Q5, not much of a high end of headphones but they get the job done.

I've been using the HiBy R3 Pro II for a few weeks now, and I wanted to share my thoughts on this DAP so far.

TL;DR: The HiBy R3 Pro II is a fantastic DAP with excellent build quality, outstanding audio performance, and comprehensive connectivity options. While the UI has room for improvement, it's a solid device overall.

I'll cover what I feel most important, however, if I skip something you're interested in, I'm more than happy to expand.

So let's get started then:

Build Quality

The R3 Pro II is exceptionally well-built. It feels solid in hand with a satisfying weight that conveys quality. The Ultrasuede back was the primary reason I chose the R3 Pro II over other HiBy OS DAPs—it feels absolutely wonderful to hold, provides excellent grip, and is a refreshing change from the usual textureless backs found on most devices.

The buttons have a nice tactile feel, though the layout takes some getting used to initially. The status light on the power button is a nice touch (though it can be disabled in settings if you prefer).

Audio Performance

Simply put, it's perfect. Out of the box, the R3 Pro II has a conservative volume limit, but you can adjust this through developer options. On high gain, it easily drives my HD650s without breaking a sweat, while low gain provides more than enough power for any IEM.

A standout feature is MSEB, a HiBy OS exclusive that lets you fine-tune the sound to your preferences. Unlike traditional EQ, you're adjusting the overall sound signature rather than specific frequency responses, which feels more natural and musical.

User Interface

This is where the R3 Pro II has the most room for improvement.

The overall UI is attractive, mostly responsive, and intuitive to navigate. Settings are easily accessible, and most functions work as expected.

However, the library views—where it matters most—are problematic. The "Artists" view lists featured artists and collaborators as separate entries (similar to the iPod Classic), which becomes annoying with larger libraries and could be a dealbreaker for some users. The "Album Artist" view is similarly clunky. While it lists artists cleanly, it doesn't allow browsing by albums, instead displaying all tracks in a single list, making it nearly useless for my needs.

If HiBy implemented the filtering and sorting options from the Artists view into the Album Artist view, it would dramatically improve the experience for users with extensive libraries.

Other library views work as expected without issues.

Wired Connectivity

The R3 Pro II offers excellent connectivity options with 3.5mm, 4.4mm balanced, and USB-C connections.

The balanced 4.4mm output on high gain is impressively powerful—I could drive my HD650s comfortably at 60-70% volume, well above my usual listening levels.

The USB-C port is remarkably versatile, supporting both input and output DAC functionality. USB DAC mode worked flawlessly with my MacBook Pro, handling everything up to 32-bit/384kHz. I was even able to connect a USB-C dongle DAC (CB1200AU), which was detected and worked perfectly.

Wireless Connectivity

Bluetooth connections proved stable with excellent range, though there's noticeable latency (200ms-1s at worst in my testing).

I tested with TRN BT20 Pros and Sony WH-1000XM3s using both AAC and LDAC codecs—both worked flawlessly. While I don't have aptX devices to test, I expect they would perform equally well.

Connecting my iPhone 16 Pro Max via Bluetooth was seamless with rock-solid stability. The practical utility of this feature is debatable, but it works well when needed.

WiFi performance is solid despite only supporting 2.4GHz. The connection remained stable throughout testing, and I could stream Qobuz and Tidal up to MQA without issues. Both streaming service interfaces work well, allowing easy access to your library, playlists, new releases, and recommendations.

HiBy Link worked adequately—I could connect my phone to browse music and control the R3 Pro II remotely. However, it didn't perform as well as expected and only worked over WiFi in my testing, though it's supposed to work over Bluetooth as well. This isn't a concern for me since it's not a feature I'd use regularly.

The Import Music via WiFi feature worked well. The web interface is minimal but functional, allowing you to browse the SD card and upload/download files at reasonable speeds.

I didn't test the DLNA functionality.

Battery Life

Battery performance is excellent. I achieved around 15 hours of mixed use (Bluetooth and wired listening, frequent screen use, WiFi enabled, lots of tinkering). With more conservative usage, 20+ hours should be easily achievable. Standby time is outstanding—I never noticed battery drain when the device wasn't in use.

Conclusion

The HiBy R3 Pro II is an outstanding DAP that excels in build quality, audio performance, and connectivity options. While the user interface has some shortcomings, particularly in library management, the overall experience is very positive.