Sound Analysis.

Before doing any critical sound analysis, I had R01 w/N6ii on burn-in for about 4-5 days playing various tracks in the loop.  Afterwards, for a critical listening I used Oriolus Traillii to analyze the sound using my usual test tracks, such as Agnes Obel “The curse”, Sandro Cavazza “So much better” (Avicii remix), C-Bool “Never go away”, Ed Sheeran “Shape of you”, Alan Walker “Darkside”, Galantis “Hunter”, Iggy Azalea “Black widow”, Indila “Boite en argent”, Counting Crows “Big yellow taxi”, David Elias “Vision of her”, and Michael Jackson “Dirty Diana”.

In my opinion, the best way to understand and to describe the tonality of N6ii modules is by comparison of one to the others.  And while it is convenient to have access to two DAPs for a true A/B comparison, I was actually able to do a module hot-swap.  Cayin doesn’t recommend swapping modules while powered up, but it works without a problem and the DAP even remembers the last volume setting for that specific module.  It took me literally a second or two to swap between modules when doing the comparison.  But as a DISCLAIMER, do it at your own risk.

R01 vs E02

E02 has been my favorite N6ii module, so I was very curios how it will compare to a new R01.  The first thing you notice is a more analog tonality, with the sound being noticeably smoother.  I never found E02 to sound ‘digital’, but when you compare these two side by side, I find R01 to sound smoother and more natural.  This is not the type of smoothness where you lose resolution or retrieval of details, and you shouldn’t expect the sound to become warm and colored. The signature and the technical performance are on the same level as E02 with its Class AB amp, but the tonality of R01 is more analog, more natural, and smoother.

A closer listening shows E02 bass to have more impact, hitting stronger, and treble to be crisper, while the decay of notes being faster, making the sound tighter and the background blacker. In contrast, R01 sound is more relaxed, more natural and smoother due to a decay of notes fading into the background instead of being sharply cutoff.  R01 bass has more weight, still an impressive impact quantity, but a little less than in E02.  And the same goes for treble, R01 is a little smoother in upper frequencies, nothing rolled off, just taking the edge off the crisper treble I hear with E02.  The soundstage expansion and imaging are very similar.

Another difference when comparing to E02, R01 background is quieter with sensitive IEMs.  And in R01 when comparing 4.4mm to 3.5mm outputs, balanced output has a wider soundstage and a blacker background which is quite noticeable.  But when looking for background hissing, while using CFA Solaris ‘20 and switching between E02 and R01, the background “waterfall” hissing is more noticeable with E02.  Another thing to keep in mind, while lacking LO in comparison to E01/02, it was more convenient to have both SE and BAL output in R01 card.

In my E02 review I covered comparison with all the previous audio motherboards.  To make R01 review fully complete, I decided to include copy’n’paste of that section below.

E02 vs E01 (AB) – E02 soundstage is a touch wider, and while I was impressed with soundstage expansion of single ended E01 output, E02 spreads L/R a little bit further apart.  Bass (E02) has a bit more impact and more rumble with a velvety texture, mids have a little more body especially in lower mids while E01 mids sound more transparent and E01 treble is just a little bit smoother, making E02 signature more organic, placing E02 performance between E01 (A) and E01 (AB), though being closer to E01 (AB).  But in general, E02 is not too far off from E01.  Also, despite a rated difference in output power, regardless of IEMs or headphones, I hear a difference of about 5-6 volume clicks.

E02 vs T01 – T01 soundstage is a little bit wider, perhaps due to a brighter tonality with airier treble.  T01 bass is faster and tighter, with shorter decay, mids are brighter, more revealing and micro-detailed while E02 mids are more natural and smoother, and have more body.  The treble of T01 is crisper and brighter.  The preference here will depend on the signature of IEMs/headphones and how it pairs up with either of the modules.

E02 vs A01 – E02 soundstage is a little wider.  Overall tonality is similar, but there are some differences I’m picking up.  E02 bass has more rumble and more analog texture.  Mids are similarly smooth, but E02 has more organic layered natural texture.  I went back and forth many times comparing these, focusing specifically on mids, and that texture and better layering and separation is what makes E02 stand out, especially when it comes to vocals.  Also, E02 treble has a little more sparkle and airiness.  Overall, E02 sounds like it has more analog texture, better layering, and improved sound dynamics in this comparison.

Comparison.

In every comparison I used Oriolus Traillii, volume matched while listening to the same test tracks between DAPs.  Furthermore, I mostly focusing on the difference in sound as I hear it without going too deep into the design and functionality differences.

N6ii w/R01 vs A&K SE180 ESS – In my recent SE180 review I compared their ESS module against N6ii with E02, and found tonality to be very close.  Moving up to R01 from E02, the tonality is not too far off either, though I do find R01 to be more analog, more natural, and with a tighter bass punch.  But those are all fine-tuning details.  What really does stand out and quite noticeable is a wider soundstage of R01 with a more realistic imaging in comparison to SE180/ESS which has more depth and less width relative to R01.  Another difference was a blacker background of R01, giving overall sound a better definition.  I also find fully open Android OS with access to Google Play in N6ii to be an advantage over A&K limited side-loading of apps.

N6ii w/R01 vs Lotoo LPGT – This was another interesting comparison because I use LPGT quite often in my testing due to its relatively neutral transparent sound quality.  Comparing it with R01 demonstrated that R01 analog smoothness is not a result of extra warmth or additional coloring.  It is due to a technical performance enhancement rather than changes in tonality.  This comparison also shows that, unlike E02 with its slightly elevated bass impact and treble sparkle, R01 is more balanced in tuning and its smooth analog textured sound is still neutral and natural like LPGT.  Last, but not least, have to keep in mind that N6ii is Android DAP while LPGT is audio playback only.

N6ii w/R01 vs L&P P6 Pro – If we talk about discrete resistor R-2R ladder DAC, you can’t avoid the comparison with P6 Pro which also features R-2R discrete resistors DAC.  To my surprise, these had a few interesting differences.  They both share the same natural analog tonality, but while R01 has a slightly more laidback presentation of the sound with a little longer decay of notes, P6 Pro sound is tighter, faster, and with a blacker background.  Another interesting observation was with vocals, where using Traillii I heard vocals being pushed slightly back with P6 Pro, and brought a little forward with more focus with R01.  You do have to keep in mind P6 Pro cost 2x more and audio playback only non-Android player.

N6ii w/R01 vs Hifiman R2R2k (red) – Both have a similar wide soundstage expansion and imaging.  The tonality difference is the first thing I noticed, with R01 being smoother, more laidback, while Red being more revealing, still natural but not as smooth, even a bit more digital when you do a close A/B comparison.  One difference that really stood out for me was a high level of hissing of many IEMs with Red in comparison to R01 that handle it a lot better.  Even with something like Traillii, zero hiss with R01 while it was quite noticeable with Red even in Low gain.  I’m not even going to touch functionality comparison since R2R2k is very limited and primitive.

Page 3 – Pair up, and Conclusion.