Here is how RS8 pairs up with some IEMs and headphones. In each pair up I noted the volume (V) setting. All were connected using 4.4mm BAL and tested in high gain and Turbo mode.
Audio-Technica ATH-R70x (V55) – These 470ohm open back cans are usually not as easy to drive, here set the volume to 55 with no issues and plenty of overhead. The soundstage is wide, but I do hear more depth/height in comparison to width, though imaging is still 3D holographic. Sound signature is balanced, and tonality is on a warmer side, being more organic, smoother. There is no lack of retrieval of details, despite a warmer tonality with a smoother presentation of the sound. The bass performance is great, with a deep sub-bass rumble and softer mid-bass punch. The bass punch is more relaxed, and sub-/mid-bass tuning is quite linear. Mids are very natural, organic, very detailed and quite resolving while still being smooth. Treble is also clear and detailed, very natural, with moderate amount of airiness and sparkle.
MEZE Audio Empyrean (V41) – I hear a wide-open soundstage with an excellent holographic imaging, with the sound extending further out, more out of your head. The soundstage has more depth/height than width. Sound signature is closer to balanced, and the tonality is warm, natural, very organic. Bass has a deeper sub-bass rumble and rounded mid-bass punch. The weight of the bass notes comes mostly from sub-bass, mid-bass is there, packs a good punch, but with a slower attack. Lower mids are a bit north of neutral, adding more body to the sound, while upper mids are smooth and warm, with a slightly pulled back presentation. Treble is clear and detailed, has a little extra crunch but nothing harsh or splashy. The treble is airy and extended. With deeper sub-bass and extra crunch in treble, and upper-mids being pulled slightly back, the overall balanced sound sig is leaning a bit toward U-shaped tuning.
Beyerdynamic T5p 2nd (V37) – Excellent soundstage expansion in all 3 directions, along with 3D holographic imaging. The sound is relatively balanced, very natural, and unlike other two headphones, actually a bit more revealing here. The tonality is leaning more toward natural-revealing side with less coloring. Bass has a deep textured sub-bass rumble and tight punchy mid-bass. The weight of bass notes is distributed evenly and not as elevated. Lower mids are closer to neutral, maybe just a touch north of it, and have a natural amount of body, while upper mids have more clarity, transparency, still natural, but more revealing in comparison to other pair ups. Vocals came out clear, detailed. Treble also has plenty of clarity, details, and natural sparkle with a good airy extension.
Overall, the pair up with headphones was impressive since the sound was natural and still detailed. I especially enjoyed R70x pair up, among the best I tried without a need for an external amp.
Oriolus Traillii w/Chiron (V28) – Wide soundstage with 3D imaging, though I do hear more depth/height than width. Sound signature is perfectly balanced, overall tonality is natural and a bit more revealing toward upper mids. Bass goes down deep, with elevated textured rumble and softer rounded mid-bass impact. Bass has an impressive impact with more focus on sub-bass. Mids are very clean and natural, with plenty of body in lower mids and organic detailed tonality in upper mids, quite resolving and detailed. Treble is clear and detailed, has extra sparkle and crunch in mid treble. This pair up maintains a natural resolving tonality and even helps to bring out upper mids/vocals a little more forward.
Aroma Jewel w/FT (V30) – The soundstage is wide with holographic imaging, though I do hear more depth/height than width. Sound signature is balanced as well, while tonality is natural, organic, with a revealing presentation of the sound in upper mids. Bass goes deep, with a textured sub-bass rumble and a punchy mid-bass; the bass is tight and articulate. Lower mids are a bit north of neutral, adding a little extra body to the sound. Upper mids are natural-revealing, not too bright, but with excellent retrieval of details. Treble is crisp and detailed, still natural and with excellent airy extension. Going from fw 1.02 to 1.04 improved the treble in Jewel, adding more sparkle to the sound.
Empire Ears Odin (V27) – I can confirm a pitch-black background with zero hissing even at high gain in Turbo mode. The soundstage here is huge, and the imaging is holographic. Bass extends deep with a textured rumble and mid-bass has a strong tight punch. Lower mids are neutral, maybe a bit toward the leaner side, while upper mids are natural, revealing, very detailed, and nicely layered, though a bit distant out of my head. Treble is crisp, clear, detailed, natural-revealing and yet, without any sign of splashiness. The overall sound is leaner and more revealing, but still maintains a natural tonality.
FirAudio XE6 (V28) – A big holographic soundstage expansion, quite wide though I feel there is a bit more depth/height with the sound projecting more out of my head. Unlike other sources paired up with XE6, this one has a more balanced signature with a powerful speaker like analog bass, thanks to XE6 kinetic bass drivers, natural detailed mids and vocals which are just a touch recessed, and crisp natural treble. One interesting observation, while in many pair ups I prefer custom XE6 over uni XE6, here I felt the opposite since custom XE6 had vocals a bit too close, and I like how uni XE6 extended vocals a little more out of my head, making it feel like I was at a live concert. Absolutely loved this pair up.
Campfire Audio Solaris 2020 (V17) – This being Campfire Audio iem, the first question is always, does it hiss? The background is pitch black, and I don’t hear any hissing at all. The soundstage is wide, with an overall sound being quite holographic. The sound sig is balanced, while the tonality is neutral revealing with a bit of a natural warmth. Bass has a deep sub-bass rumble and a fast well controlled punch, though the weight of the bass is not elevated. But it is for sure above neutral and unmistakably DD quality. Mids are natural, revealing, very detailed. Surprisingly, I don’t hear any sibilance in lower treble. It is still energetic with a nice natural crunch, but the treble is not elevated or fatigue. This was another example of a great pair up.
UM Mest MKII (V28) – Wide soundstage expansion, though I hear more depth/height than width. Typical of Mest MKII, I found U-shaped sound signature, even leaning more toward balanced, with a deep analog quality dynamic bass where I hear more emphasis on sub-bass rumble which adds extra weight to the low end. But mid-bass also had a nice tight punch. Lower mids are neutral, just with a touch of extra body, but overall, they are neutral which brings more attention to natural-revealing upper mids. Treble is bright, crisp, airy. It’s a great pair up if you like more bass and a natural crunch in the sound.
I enjoyed RS8 pair up with IEMs as much as I did with headphones.
Wired and wireless connections.
Besides being a portable DAP, you can expand RS8 functionality as a transport to drive external DAC/amp, to use external AMP, or to turn the DAP into wired/wireless usb DAC. And of course, you don’t have to be limited to wired headphones, and can take advantage of Wireless Bluetooth connection.
I tested RS8 BT Tx with Hiby WH2 TWS, confirmed operation within 40ft. UAT codec support was recognized and I was able to pair up using it as default hi-res codec. Also, confirmed full remote control of the playback from WH2. The stability of the connection, covered distance, and sound quality was no different than using my Galaxy S22 phone.
RS8 also has BT Receiver mode which turns this DAP into a wireless DAC/amp. Simply go to Bluetooth menu, click on Bluetooth Audio Input, and search for RS8 from your smartphone. When paired up, make sure in BT setting on your phone you click on gear setting icon next to RS8 and select LDAC.
USB Audio Out.
I tested and verified this one with various popular USB DAC dongles, such as RU6, S2, and W2, and found it to work without a problem. Similar to how I have it configured in HibyMusic with my Galaxy S22, I had Exclusive HQ USB audio access enabled and selected USB Audio Performance mode. When any of the USB DAC dongles were connected, RS8 asked to allow access to that device, which you have to OK. Volume adjustment was directly from the dongle rather than RS8, and the sound quality was no different when connecting these dongles to my Galaxy S22 phone.
I verified this operation using my ThinkPad T480s laptop running Win10 Pro. Once connected, swipe down Notification bar on RS8 and tap on USB Preferences, then select either Audio in (USB charge) or Audio in (no charge) to enter USB DAC mode. From USB DAC screen you have access to change audio settings and enable Bluetooth. No drivers required, Win10 recognized the DAP without a problem, and RS8 was selectable in Windows Audio Setting. Volume could be adjusted from Laptop and from RS8. Sound is the same either playing directly from RS8 or playing the same song from laptop with RS8 connected as USB DAC.
With a provided usb-c to coax cable, you can turn RS8 into an audio source/transport. Just plug it in, connect to external DAC/amp, and it works right away. I was using iFi micro iDSD BL and everything was recognized without a problem or the need to enable anything in Settings. Volume was only adjustable from micro iDSD, not RS8. And actually, with micro iDSD BL the sound was even better with Coax than digital out.
RS8 has automatic detection when Line Out is connected, then sets the RS8 volume to Max 100 so you can only adjust the volume from external amplifier. I did my testing with Cayin C9 amp. If you need more power or want to expand your soundstage and add more air and sparkle to the treble, pair up of RS8 with C9 is a great way to get there. The sound remained natural and organic, and you can select NuTube for more analog texture. Also, switching to NuTubes on C9 widened the soundstage expansion, that was quite noticeable.
I mentioned in the intro of this write up that it is becoming challenging to review flagship DAPs since they all sound good and there is an overlap in functionality. When I received RS8, it didn’t take me too long to realize that its tuning would make a great complementary addition to other DAPs with more neutral or more revealing sound. RS8 has a natural organic tonality with a resolving tuning. It was darker out of the box, but the top end opened up after the burn in, and the latest fw update solidified its resolving tuning. The natural organic tonality of RS8 comes from its fuller body mids and textured blooming bass which also gives the sound a more intimate feeling due to a center-focused imaging. Of course, I’m describing the sound relative to number of IEMs I tested using RS8 as my source and while comparing to other DAPs.
Is RS8 a groundbreaking innovation? Not exactly since we already seen introduction of Darwin architecture and discrete R2R DAC in their RS6 release. RS8 is the next logical step, taking RS6 to the next flagship level with a more refined natural tonality and updated Darwin II along with R2R where they doubled the number of discrete resistors and switches. RS8 has a phenomenal battery life even at high gain and from a balanced output, though a bigger battery contributes to more weight. Its Titanium finish looks distinct, perfect for showcasing this transportable on your desk, maybe even with Hiby’s optional CR08 cradle dock. The flagship DAP market starting to get crowded. But if you are looking for a source with fast optimized Android OS and a more natural fuller body tonality which still has plenty of resolution, RS8 deserves a serious consideration.