Under the hood.
A lot of the internal R6Pro design remained the same as in R6. It still uses Snapdragon 425 SoC Processor (clocked at 1.4GHz) and 3GB of DDR3 RAM to deliver a fast Android 8.1 experience. Internal storage is still 32GB, and you have a single uSD expansion to support the latest max capacity cards, currently at 512GB. Plus, wifi streaming and LAN support expands the playback beyond the local storage.
Audio processing is still under control of dual ESS ES9028Q2M DAC, but the amp section has been revamped to feature 4x Muses 8920 and 2x SSM6322. As you can expect, different amp chips will yield a different sound coloring which I’m gonna cover in sound analysis section next. And with new amp section, the output power went up significantly with 3.5mm Single Ended: 245mW @32ohm load and 4.4mm Balanced: 750mW @32ohm load. Also, output impedance went down from 10 ohm to 0.28 ohm!
All major hi-res lossless formats are supported so you are covered to play FLAC, APE, WMA, WAV, ALAC, Apple LOSSLESS, DSF, DSDIFF where you have native support/decoding of DSD 128/256 and PCM up to 32bit/384kHz, as well as support of ISO DSD. Plus, support of lossy formats, such as MP3, AAC, WMA, OGG. And as usual, Hiby modified OS is able to bypass Android sample-rate conversion to ensure bit-perfect output from any app.
You will also find the same 4.2-inch touch screen IPS display (high-density 300 dpi) with resolution of 768×1280, supporting 16 million colors, and wide viewing angle. Furthermore, for a wireless connection, you have dual-band (2.4G and 5G) WiFi radio, and Bluetooth 4.x supporting aptX and LDAC.
Plus, the same battery with 4000 mAh capacity and support for quick charging (QC 3.0) standard (140min to full charge), where you can use either DC 5V/2.5A or 9V/1.5A. While Hiby mentioned about 12hrs battery life which is impressive for high performance touch screen Android DAP, in a real life usage with a mix of mp3 and flac files, balanced output, and using IEMs, I was able to get closer to 10hrs of playback. With DSD, as expected, the playback time goes down due to a higher battery drain.
I analyzed R6Pro sound with U18t while playing a variety of my favorite test tracks, such as Agnes Obel “The curse”, Sandro Cavazza “So much better” (Avicii remix), C-Bool “Never go away”, Ariana Grande “Break up with your girlfriend”, Ed Sheeran “Shape of you”, Galantis “Hunter”, Iggy Azalea “Black widow”, Indila “Boite en argent”, Robin Schultz “Oh child”, David Elias “Vision of her”, and Michael Jackson “Dirty Diana”.
Since I had R6Pro in my constant review rotation for the last few months, it has easily over 100hrs of playback time. And in my usual disclaimer, DAP sound analysis could be a bit tricky because you are describing the synergy of the DAP with headphones you are listening to. It’s easy to fall into a trap of describing the headphone signature, thus I usually go through a number of headphones, from neutral to more revealing, to find common sound characteristics relative to the source, rather than headphones.
While I found the original R6 to be a neutral player with a tilt toward a brighter more revealing side, in comparison R6Pro has a fuller body with a more natural sound tuning. R6 has a more transparent, less colored, more revealing leaner reference sound, while in contrast R6Pro extends the bass with a deeper rumble and more analog texture, adds more body to the lower mids which is noticeable especially in vocals being more organic and natural, and takes a bit of sparkle off the treble.
Overall, the technical sound performance is very close, though I felt that the original R6 had slightly better layering and separation, perhaps due to more transparency and more airy treble which creates a sense of more air between the layers of the sound. Also keep in mind that R6Pro is a lot more powerful and has a lower output impedance. But with higher power you have to be aware that some sensitive IEMs will exhibit more hissing, requiring you to switch to low gain or look into iEMatch again. There is always a trade off with higher power, and this is one of those cases.
Also, I noticed an occasional EMI interference when WiFi and Bluetooth were on, just an intermittent crackle and not with every IEM/cable. These artifacts were more noticeable at very low volume level, while at normal listening level those were hard to hear.