Reviews by Sharppain


500+ Head-Fier
Hiby RS2 - R2R DAP Surprise
Pros: + Capturing R2R presentation
+ Natural timbre, zero digital glare
+ Solid detail retrieval
+ Wide soundstage and spectacular depth
+ Very good battery life
+ Premium build quality
+ Comes with a carrying case and premium rare cable USB - Coaxial
Cons: - Many filters but not clear which is what (no names)
- No BT or Wi-Fi connection
- A short Type-C to Type-C cable is missing
- Menu is simple but some illogical in structure (for me)
Last year, HiBy released the RS6 digital audio player – a solid, full of functionalities, R2R DAP (I still haven’t laid my hands on it because of its price). The RS6 started the premium R2R-based Darwin Architecture for portable digital audio players for the brand.
And recently Hiby launched the RS2 which got my attention immediately since it had an affordable price level while bringing the goodness of R2R DACs with modern functions like adjustable FIR filter, Harmonic controller, NOS/OS, etc. It is a pure audio player with the HiBy OS PureAudio version. I bought it immediately when it appeared in MusicTeck website (should out for them – wonderful service!).


The player comes loaded with a specially tailored OS - a simplified user interface and menu structure (no Android). It is my first real DAP (I have the Fiio Q5S but it is not a real DAP for me).

So, here I present to you my initial 20-day impressions. Please, have in mind that this is a bit unorthodox review – I am not the polished reviewer type, engaged dedicatedly to providing reviews, sourced by companies and the community with precious and new gear. I review and comment on what I have, what fits my collection, what I find unorthodox like a product, the gear that impresses me a lot (or disappoints me) and is still uncovered, according to me.

The Hiby RS2 is not a big device – the photos in the ads created wrong expectations; it is small like a pack of cigarettes – a bit wider and thinner, but shorter. But it feels heavy, solid piece of gear with a premium design and materials. I wish it was not that shorter for my hands and the only critics I have on the accessories is that USB Type-C cable is provided but a short Type-C to Type-C is not (my use case for the MQA is sourcing from phone).

The most other attractive facts for me are:
  • RS2 features OS (OverSampling) mode and NOS (Non-OverSampling)
  • The Darwin architecture here houses a 256-tap adjustable FIR filter. It is capable of up to 16x oversampling with a variety of AA filters like Phase linearity, High-Fidelity, etc.
  • HiBy has featured an FPGA clock system with precise dual crystal oscillators.
  • The player comes with a high-current mode amplification circuit with an OPA1652 and an LPF circuit with dual OPA1612 chips.
  • RS2 comes with a single-ended 3.5 mm and balanced 4.4 mm headphone output ports.
  • HiBy RS2 supports high-resolution PCM, and DSD signals. It supports PCM signals up to 32-Bit/384kHz and native DSD256 decoding. RS2 also supports 8x MQA
  • RS2 with dual memory card slots each supporting up to 2 TB of microSD cards.
  • HiBy RS2 has got a large 3500mAh battery (close to 10h at higher gain at 30%. Delivered during my 4-day ‘test’)
  • For all the rest – check the official website:
Yes, I want to stress on the expression ‘listening impressions”. Some time ago I was fascinated by the Cayin RU6 – it changed a lot for me making me buy the Ares II and later upgrade to IFI Pro iDSD looking for the naturalism and musicality plus a solid technicalities like sound stage width and depth, layering, … So, what I will speak about are not the mere specs neither if this is the most hi-tech device you can get, neither will use fancy reviewer expressions - I will focus on the R2R performance, what does it give me and will try to explain it in simple words. So...

The Hiby RS2 dac has close to linear frequency response with a bit of warmth and light mid-centric focus, very good technicalities and wonderful transparency. The amp increases a bit more the mid-centric focus.
The presentation is always very smooth, coherent, and balanced while being also immersive and musical. There is zero digital glare, timbre is natural and all instruments and female/male voice sound naturalistic and capturing. The sound is textured and alluring but everything is well controlled without color and too much intensity and artificial energetics.

I think the upper part of the frequency spectrum is very slightly subdued – do not get me wrong, it is not rolled off, all the information is there, the extension is very-very good and everything is clearly catchable, just it is not presented with many sparkles and flashes.

The bass is well present, tight, and clear. It is never too much, neither not enough. I am very impressed with bass since it is full of texture but fast. And it made we go back to some gear that was put aside - later you will understand more.

The mids and volcals – depends on how you like it! What do I mean!? At the Cayin RU6 and the Ares II I do prefer on OS mode. With the RS2 I change b/w OS/NOS – the OS makes the reproduction a bit more mid-centric but well smooths the flaws of some recordings, also OS makes the vocals sometimes come closer and some-how that shrinks a bit the sound stage; the NOS mode sounds highly organic, natural, well layered, a bit more expansive, and I cannot say I am missing smoothness often.

The lack of lushness and sparkles in the presentation is compensated by the excellent imaging - there is an amazing space between instruments for a DAP, there is very good layering and depth of the stage, and nice 3D. I cannot say that the fidelity is just 100% (last two months I got spoiled by a set-up of IFI Pro iDSD –> Burson Soloist 3 XP / Stax SRM-007t Mjolnir) but the great combination of dynamics with natural timber plus naturalistic presentation with great coherence plus the convincing soundstage integrity are marvelous. Just imagine you listen to WASP’s ‘Keep Holding On’ and ‘The Idol’ at a concert – yep, the RS2 did it close for me; a smidge below the Ares II (except for the sound stage width). To conclude the RS2 has natural, clear, well-articulated, balanced, rich but not analytical presentation. It is quite above the RU6 nearly trying to reach for the Ares II.

Yep, the menu is fairly simple but there are some illogical decision about its structure. Here are the most things which I refuse to accept: 1/ Why the Gain is buried in the Play menu so down, next to the Crossfade?! and can be accessed only from the Home screen; 2/ Why the NOS is in the Darwin menu!? Only Darwin has NOS/OS!? and can be accessed only from Home screen.

There is no easy way to wake up the screen when it sleeps – you must tap twice on the screen!!! and most often need a second hand or use a short slide of the power button. And then the screen you get is a clock but not the band/song you are playing!!! so you must slide that screen right. Reaching the Home screen when playing music needs several slides right since you’re a going back through the folders structure, and the NOS/OS and Gain and Crossfade you can reach only from Home screen going back and back. Only the Equalizer and the Equalizer styles like Pop/ROCK/Jazz… is easy to access. Screen is too short for the many functionalities in each menu and the long songs titles are not shortened by .....

The volume button scale can be fine tuned from the menu and is very precise and with nice tactility when rotating. The other three buttons for song forwards/backwards and pause/play are easy to find and operate.

Otherwise, many of the functionalities are really useful – I find especially well implemented the Crossfade, it is just enough. I like very much the Darwin’s Harmonic controller – I feel like it gives me the chance to choose between bigger space b/n instruments plus bigger soundstage vs more musical reverberation, sometimes resembling tubes type, and balance between these. Also the MSEB menu with Overall Temperature, Bass extension/texture, Note thickness, Vocals forwardness, Sibilance, … worked very well for me in some cases, but I do not believe with it since it is a bit tricky to fine tune – the sensitivity is too big. Also I still cannot find a way to save profiles, guess it is not an option.

I will not quote the power output specs and speculate on them – empiric impressions and experience are more valid for me. Noise from the 3,5 mm or 4,4 mm is not existing for me – zero!
I dare to make the following statement – nearly every iem from my big collection does well with the Hiby RS2. Even more, in most of the case, I felt like the RS2 knows what should be improved in the iems' FR presentation. Examples:
  • 7hz Timeless runs with zero sibilance and an gets absolute bang for its money;
  • the JVC HA-FDX1 is not at all lean sounding in the bass and gets good bass hump;
  • the Blessing2 Dusk gets very musical and presents very big sound stage - I rediscovered its high qualities and started loving it a lot;
  • the ThieAudio Legacy 3 is an absolute bliss of musicality; btw it is a very sensitive iem which is a benchmark for me for the noise floor – no issue with the RS2;
  • Sony IER-Z1R – oooOMG, the RS2 brings the vocals a bit closer and the presentation is with abnormally wide sound stage for an iem;
  • The UM Mest v1 – this pairing is end-game for me, I will not buy any other iem before I test it personally (do not make me bet on that, please)

The RS2 is a bit peakier with the headphones. Strangely it didn’t make shine some headphones with low impedance like Focal Listen and Elegia, also DT770 pro 80 ohm but paired really well with DT880 pro 250 ohm, DT1990 pro, the Sennheiser HD560s, the Sundara, the HD800s and the Arya was a bit to much for the RS2, according to me. And again, the effect on the headphones’ performance is like with the iems - the RS2 mitigates any imperfection of the headphones FR. Any bass leanness is noticeably ‘compensated’, any peak in the highs or sibilance is smoothened (suppressed) – I am very impressed. Just the power is not enough for some of then - I am constantly at 60% of Gain ON and sometimes more (on the other hand after 50% the power given starts pumping up very well).

If you don't mind something bigger than a dongle but still compact to carry in a pocket (still heavy and bulky) and would like to have the real R2R presentation always with you, than RS2 is a perfect gear for that. It deserves any penny. I am already convinced I will not regret my purchase and that the Fiio Q5s will start getting dusty. Meanwhile I will never miss my Ares II fully when on the go. It is not a highly energetic presentation that you get - it is one to enjoy with focus but w/o intensity.
And most important I started rediscovering my iems and some headphones – the RS2 is reviving some of them to me which makes me very happy. Even more, many times I found myself feeling that I am connected to a desktop set-up.

This review was firstly published on Sept 15th, and now is slightly updated.
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Thank you for sharing your experience. I might be having one of this soon. My pursuit for overly analytical gears is over. I have concluded to myself that being too analytical takes away the enjoyment of music. And so my hunt for r2r begun. And i think rs2 will give me what I'm looking for. Soul, musicality and emotion in my music. Well i hope so. 😎😉
Hi, on mine I disabled keys when the screen is off, I disabled the double tap to wake. I just flick the power switch to the right and it wakes up.

I don't have the most resolving IEMs (listening right now to the RS2 over a pair of Shure 535) and I have a very difficult time hearing anything in the filters. Between OS and NOS it seems like the major change is the imaging. OS is more centered, NOS seems more natural. I have a NOS DAC in my big rig and I prefer it.

Thanks to all the guys who reviewed this unit. It helped in my selection.


500+ Head-Fier
Cayin RU-6 - the Portable Bliss to Enjoy an R2R Replay!
Pros: - Solid and elegant build
- Combines natural replay (especially vocals) and very good resolution
- Wide soundstage (especially depth)
- Good imaging and instrument separation
- NOS and OS like two different sound signatures
Cons: - Might be prone to scratching
- Delay when volume increase (especially when not warm)
In the portable music world, Cayin is well known brand that offers product range from the budget N3 Pro up to the flagship N8 with the N6ii sitting in the middle. Now Cayin offered portable R2R dac/amp at affordable price that, according to me, will win many fans. For me it is a bit a game-changer since the price you pay for getting into the R2R replay is peanuts.

Cayin took a bold step and built the RU6 with thin-film resistors with 0.1% precision and a 25ppm temperature coefficient and brought the price tag inline with some leading MQA dongles thus setting a challenge to other premium brands. And according to me it achieved building a very solid product and R2R replay.

The RU6 offers two gain levels and 3.5mm single-ended and 4.4mm 'balanced' outputs (the 4.4 is not a real balanced, it has 4.4 balanced power). The RU6 also offers oversampling as an option that increases the bit-rate of the input sample to 384kHz - it decreases noise and increases detail level; according to me, both NOS and OS have very solid replays.


One of the achievements that surprised me most is that RU-6 drives successfully not only demanding iems but also demanding headphones - it drivers perfectly the Z1R iem but also the Z7M2 headphones, it also drives very well the P1 but also even the T60rp (for the headphones I used the 4.4 output). Meanwhile, I do not hear any hiss even with sensitive iems like Thieaudio Voyager 3 or Andromeda.

Technicalities, Replay and Timber
The RU-6 has a very natural tonality (especially for vocals) with good detail retrieval - I find it very natural R2R sounding and do not miss resolution:
- Bass is tight, sub-bass goes deep, there is good detail and separation between sub-bass and bass.
- Mids and vocals are naturally warm, naturalistic and have very good details. They are a little bit forward but in a very good way that doesn't overpower the bass and treble. These are mids that give you the entry level to R2R signature - do not expect Ares II performance but the level produced is far different and higher in naturalism than leading MQA dongles.
- Treble is done perfectly well for me, no roll-off, good resolution and airiness, details are not attacking your years but are well articulated. They fit the whole signature very well and play good role for the sound staging.

The sound stage is wide, especially in depth; the layering is impressive; the separation between instruments is solid and I even find that RU-6 has 3D presentation. Attack and decay on/of tones is fully Ok.

I cannot give description how the RU-6 matches the 100s of iems from my collection but I will do short descriptions with some favorite of mine iems from the last 15 years:
- Sennheiser IE80 - a great pair, RU-6 opens the big sound stage of the IE80 more and brings forward the vocals;
- Sony XBA-A2 - a great pair, RU-6 controls the XBA-A2's bass very well, increases sound staging and vocals enjoyment;
- Sennheiser IE800 - RU-6 makes the vocals come forward and makes the highs more natural and airy;
- Blon-03 - RU-6 enhances the natural replay of the iem and shows that it deserves a better iem :)wink:
- Tin T2 - a very good pair, RU-6 makes the T2 even more unjoyful and shows the value of the T2;
- 7hz Timeless - OMG this combo is as impressive as the that with the Drop JVC HA-FDX1;
- Thieaudio Voyager 3 - O-o-o-o musicality bliss, mid-price perfection, endless enjoyment;
- Moondrop B2 Dusk - finally the sometimes dull Dusk gets some emotion and bigger sound stage without loosing technicalities; the pair shows the beauty of Harman tuning;
- My two top pairs - IER-Z1R and UM Mest - so perfect: well controlled bass, improved vocals , enlarged sound stage and 3D.

I will not fall in so many details on headphones since I think the point is to explain how RU-6 enhances different replays but I will outline that RU-6 pairs well with Sony MDR-7510, CAL! SE, HB560s, Sundara, Focal Listen Pro, Focal Elegia, T60rp, Z7M2, HD800s. And I really enjoyed it with the CAL! SE, the Z7M2, the Austrian Audio Xi-55 and Denon 5200 and the Sundara.

The RU-6 also pairs very well with the Burson Soloist 3X and the TEAC HA-501 enhancing the natural replay of the first and the musicality of the second and paired with these two gives me same but also a bit different enjoyment vs the Mytek Liberty DAC.

I will cover only dongles that I know very well and are good benchmarks and will make it short but you will get the point:
- vs HiBy FC3 - the RU-6 is far more naturalistic and smooth and has far better staging and layering;
- vs THX Onyx - well think that the Onyx has blacker background but in A-B test sometimes it sounds very analytical, close to clinical, and cannot compete in naturalism and sound stage wideness; I would always choose the RU-6 vs the Onyx;
- vs Hidizs DH80s - the DH80s is having good musicality but favors analytics vs naturalism of RU-6; these two are really a good pair if you like musicality, power and want a good value performance.
Also what is worth noticing is that streaming MQAs from Tidal via the RU-6 works highly satisfactory and unjoyfully for me.

I think Cayin did a great product - RU-6 is the 2021 dongle for me, a dongle that will make premium brands sweat. RU-6 value is its naturalism of replay and presenting the flavor of R2R w/o dropping technicalities. NOS and OS are giving different replay and the power is enough to have enjoyment with any iem and most of the headphones up to 300 ohms.
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Hello, sorry for my ignorance (I'm kind of new to the hobby) I own MEST MKI coupled with a FiiO BTR5 - Does the Cayin RU6 offer bluetooth capabilities? Or is it exclusively an inline DAC/AMP.

And how is the quality of the overall system compared with the FiiO BTR5?

Hello, sorry for my ignorance (I'm kind of new to the hobby) I own MEST MKI coupled with a FiiO BTR5 - Does the Cayin RU6 offer bluetooth capabilities? Or is it exclusively an inline DAC/AMP.

And how is the quality of the overall system compared with the FiiO BTR5?

What options are there better than the FiiO BTR5 - I am looking for a small form factor with bluetooth capabilities - I've heard great stuff about the LP W2. Any recommendations?

Hi, I also have the UM Mest mk1, so you get my first hand (ear) impressions. The RU6 is only inline dac/amp and fits extremely well the UM Mest mk1. And: 1/ no BT is not a deal breaker - how would you listen to music with the UM Mest and use BT, BT is crippling your music; 2/ the BTR5 is a good dac/amp but it is quite below the level of the UM Mest and the RU6. I was so satisfied by the RU6 that I immediately started choosing a big R2R dac and got the Ares II. I gave to friends to try the RU6, friends that use tubes and R2Rs and Stax-es and they were not believing to their ears. Its a gem! The only regret for me is that RU6 is a bit power hungry, like 1 hour with it from my Note 10+ is equal to -10%. So use an old phone like a player for your library, install USB Audio Pro Player app (small payment) to get a bit perfect sound out (a way around the Android/iOS modifying the music), attach the RU6 and you are well done. Can't speak about LP W2 since do not have it. But is it R2R?!


500+ Head-Fier
ZMF Eikon – wooden and natural but ....
Pros: - great build and look
- great package
- natural vocals and balanced sound signature
Cons: - heavy, fit might be an issue
- inconsistency in sound stage
- slow attack
- bad service
SPECIFICATIONS: Camphor Eikon / ZMF Eikon Solid Pads Lambskin / Impedance: 300 Ohms / Driver: Biocellulose / Weight: 500g ±20g / Sensitivity: ~98dB/mW / ZMF Stock Braided Cable 3.5 mm

Disclaimers: 1/ All shared impressions, findings and facts are relevant to the single headphone sets, not to batches; 2/ All headphones are bought by me and I am getting no beneficials and incentives for my statements; 3/ Yes, most of the impressions are subjective and if anyone decides to take decision, I advise that he should rely on his on impressions also (from trial or loaning) and also check other reviews; 4/ All impressions shared are with the stock set up of the Eikon.

Used dac/amp set-up: 1/ Tidal MQA Masters -> SMSL SU-9 -> TEAC HA-501; 2/ Tidal MQA masters -> Mytek Liberty DAC -> Burson Soloist 3X P

Used Library: Pink Floyd – The Division Bell (originals, not the remastered); Adele – 30; Patricia Barber – Higher; Daft Punk – Random Access Memories; David Gilmour – Rattle That Lock (Deluxe); Soundtracking – James Bond (24 tracks incl. Billie Eilish, Sam Smith, Madonna, Tina Turner, Louis Armstrong,…); Ozzy Osbourne – No More Tears (30th Ann.); S&M2 – Metallica & San Francisco Symphony; Deep Purple – Slaves and Master (with Bonus Tracks);

The ZMF Eikon Camphor has a long hype in the audiophile community as a high-end biocellulose dynamic driver wood headphone from Zach Merbach. Me, being found of music, iems and headphones for 30 years, finally decided to go for it as a boutique wooden headphone and got it before the end of the difficult 2021 at $1421. It is already more than two full weeks after I put it for the first time on my head and I already gathered solid amount of experience and impressions with it. So, I dared to do this review and share my impressions and feelings about it, and my content, overcoming my initial shock from it and doing lots of A-B comparisons vs other headphones from my collection. I did A-B comparisons vs Focal Listen Professional, Focal Elegia, Beyerdynamic DT770 pro and DT1990 pro, Fostex T50rp Mayflower V1, Fostex T60rp Argon, Denon AH-D5200, Sony MDR-7510, Sony MDR-Z7M2 mainly. There are other headphones that I will mention in the review to try to ‘illustrate’ well my experience. As you see, I am not planning to share the comparisons vs the Sundara, the Arya, the Sennheiser HD800s (and others) since these are fully open headphones and since I do not find it … stay with me and you will understand.

The package is impressive - the nice, large, solid, foam padded hard locking case, the greeting card, the small leaflet and the Eikon itself are impressive, each by itself and like a package. I have a small complaint about the cable – it is well done and easy to use but 1/ has no color marks for left and right and the letters at the ends are hardly visible even at daylight; 2/ it is a bit short for me ~1,43 meters with the jack. We usually complain about cable being too long, but it is unusual for me the cable to be less than 1,5 meters. And last – the cable is 3,5mm unbalanced – come on for a set that expensive could be 4,4mm balanced at least. There are no color markings for the left and right cap and the letter markings are also hardly visible.

The Eikon wooden caps are made by Camphor wood that are beautiful, with a hand-applied varnish and have impressive finish and touch, but the stock solid lambskin pads are filled in with material that is not memory foam and do not have soft touch on the scalp around the ears. They really deserve the word solid - being not soft enough and not cushy, they are not helping to handle the big weight of ~500 grams. The feeling of them around my ears is as if these are tires. I like far more the perforated lambskin ear pads which have far better touch and cushiness according to me. There is something else that I will leave for the end of the review, so let’s continue with …



I have heard/read that ZMF wants the Eikon to perform on a neutral level but with a musical flair and big natural timber. The overall tonality and FR I got is close to that below, and when I say close I mean: a/ the bass is just that north of neutral, no sub-bass rolling, more mid-bass than neutral but well weighted; b/ the mids are a bit more forward like below, especially for the vocals, c/ the treble is neutral and well controlled. I do think that mine set does not has that big dip b/n 1,5k and 2k.
Eikon FR.JPG

The low end of the headphone is smooth, well controlled and with good amount and fits the whole sound signature very. As I said it is a lit bit north of neutral but is not bass heads type, it is just well present, goes deep, bleeds small in the vocals to give the natural warmth. But there are some flaws that I will not spare: 1/ the separation between sub-bass and mid-bass is not well done, the mid-bass has low detail; 2/ I think the lack of good separation between sub- and mid-bass and something else (I will speak about the ‘else’ later) coming together make my experience with the bass, let’s say not poor, but not matching the price level. The bass performance of the Eikon with the stock pads is just slightly better than that of the DT770 pro, according to me. But I dare to say that I hear sometimes a bit more detail and separation from the DT770 pro. As I said the Eikon is not a bass heads set but let’s imagine you want more and better bass then the Sony MDR-Z7M2 is a total outperformer in quantity, quality, separation, attack, decay, detail; if you want same amount of bass but better quality then the Focal Elegia is far better, it is as better as the M7K2 but the amount of bass is less and the punch and quality strong. These two sets had recently got big discounts and that quality, separation, attack, decay, detail for ~$500 are amazing deal. And let’s say you want the same amount like the Eikon’s then the Beyerdynamic DT1990 does it equal in amount and better in everything else. I know that putting here the DT1990 pro will raise negative comments because of its notorious 8k peak but later I will give the solution for it if, it is a deal breaker for you.

So, to wrap up for the bass – good fidelity, good presence in the overall sound signature but at all not enough for the price level. And I still do not touch technicalities in detail!

I like the mids to be a bit forward. And the Eikon does it well for me. The vocals are naturalistic and impressive, both for male and female singers. Most instruments sound natural, enticing and embracing. But quality, again, is not sublime. And if you say sublime is too much than let me put it this way – not at the price level I paid. After listening for many hours, my ears never adjusted to something very specific from a technical point of view that I will speak about in technicalities. Here I will add just that mids are sometimes too intimate, condensed, and lack enough detail. Otherwise, they are realistic (but also not realistic – wait for the technicalities) and have good coherency with the overall sound signature. The Eikon is excellent vocal headphone, but not one for those who do not like a very forward midrange that pops over the bass and treble since the vocals sometimes are capturing the whole show. If you are into relaxing and chilling out mids grab some other set. And to continue with some comparisons: vs the DT770 pro – Eikon is quite better especially if you like intimacy; vs the DT1990 pro I think they are quite equal – Eikon wins in naturalism and intimacy but looses in detail and airiness; vs Focal Elegia and Focal Listen Professional – the Eikon is losing in anything, according to me, except naturalism. Even the polarizing mids of the Z7M2 are better in detail and air vs the Eikon’s. As you see, many times I mention air – later you will understand why. The Fostex T60rp Argon has nearly perfect presentation for me for the price – Eikon is more than 3 times the price of the T60rp Argon and is slightly better just sometimes.

Overall fidelity of the Eikon is good, but not fantastic. There are other sets out there with superior treble response in this and lower price tiers. The Eikon’s treble is smooth, without sibilance, not fatiguing and has also beautiful tonality and quantity. It is the treble I need for Friday night after tiresome week – one that will not attack me. Also the Eikon is not analytical in no way and though the treble is pleasant I feel very much that it lacks detail and sparkle. If you like a flat treble, the Eikon is for you, no sparkle at all, so again - not at the price level I paid. If I want to catch specific details than I have to crack the volume very high and hunt for them and again it is not working well. The Eikon treble is more macro and not at all micro – I know that doesn’t go with not fatiguing bit the lack of the detail is too much for me. I think this is coming from the tuning (the dip at 7k to 12k) and the technical capabilities of the drivers to some extent. Also I miss some vividness. And here are some comparisons: vs the DT770 pro – the Eikon’s treble is better, less fatiguing (no fatigue at all), more naturalistic but has less detail; vs the Focal Elegia and Listen Professional – they are also not fatiguing and have well controlled treble peaks but they have far more detail, they are a bit more analytical w/o being annoying and I think the Elegia is very close to the Eikon for the natural presentation; vs the DT1990 pro Eikon wins only in naturalism and if you like more brightness the DT1990 pro wins it. And if you are about to shout at mean for the 8k peak of the DT1990 pro, please, hold on – that is easily handled by installing a passive switch in the caps that kills the 8k peak (I have the passive switch installed on a custom cable that was done by Customcans from UK; the passive switch has off (8k is present) and two other on positions that tame or fully control the 8k peak), and even with fully killed 8k peak the DT1990 pro delivers far more detail. The Sony Z7M2 has far more detail that also sounds quite natural. But if you think I am overdoing it for the treble let me say – it is not the deal breaker for me, and I never expected that this would be the strength of the Eikon.

I think the Eikon is having quite decent for the price level of imaging. It is well executed, and the placement of instruments is natural, logical, and just below impressive. The instruments have decent presence and work for a good experience and enjoyment. But staging is not good. And it is not the stage width, depth or height that are the issue. It is the inconsistency of the performance in staging. When music and songs are slow, not busy, with not too many layers of instruments the staging performance is ok. But if the music gets fast, busy, with lots of instruments the Eikon’s stage is collapsing – the space between instruments is disappearing, the stage gets condensed and shrinks between my ears, the bass gets a bit muddy, the vocals change and sometimes even lose the naturalism and finish (the breathing, ticking, low vocal lingering - gone), the treble starts to lack detail fully. This inconsistent performance is one of the two deal breakers for me – it is not only that it is fully unacceptable for a headphone with that price. And I dare to say that I cannot think of another set of cans that is that bad from my big collection of several dozens of headphones or from those that start from $30 and go up to $1500; it is only the ATH-M40x that is that bad. I know that I would be hated for saying all that, but you cannot imagine how disappointing is that inconsistency – it is not like you know that the headphones are lacking the sound stage, it is like you listen to Ennio Morricone and the composition is not busy and melodical and finishes, and the next composition is fast, with lots of instruments and intense, and the stage collapses – several times I was on the brink to throw the Eikon on the ground.
Going to some comparison vs the headphones mentioned before – I do not have that big disappointment for the sound stage and the slow attack with any of them. The DT770 pro sound stage is more wider and is fully consistent, the Focal Listen and the Focal Elegia sound stage are wider and far more out of my head (the Elegia replay is like big speakers in fairly big room), the Fostex T50rp Mayflower V1 and the T60rp Argon have wider sound stage and some holographic capabilities, the Denon AH-D5200 sound far more consistent in staging, DT1990 pro has far more wider stage, the Sony MDR-Z7M2 are below the DT1990 pro but far wider sounding that all the rest, it is just the Sony MDR-7510 that sound that condensed like the Eikon, and the ATH-M40x even more, but these are monitoring cans. Frankly (and I dare to say that) even my UM Mesk and IER-Z1R are having wider stage and better spacing between instruments than the Eikon.

I already shared my impressions on the timber and naturalism for the vocals. What I want to add here is that my Eikon has really fast decay, also great smoothness, lacks graininess, and most of instruments sound the way you expect. The layering and the dynamics of the low and top end are good. If the music is relaxed the space between notes and instruments and the staging are fairly good (until the music doesn’t go intense). But, again a ‘but’, and another deal breaker for me – the attack of the notes is slow, and it is so slow that some instruments sound inverted, as if their recording is played backwards. Let me explain – imagine how drums do sound, you hear the hit and the canvas flex, and the sound suddenly grows, very fast, and after that you start to hear the decay, there is some lingering (long or short depends on the driver type), might be very small but it is lingering. Usually when we speak about fast decay that is good, and traditionally, we add tightness, you know how it is with good planars. But the attack of the Eikon on some notes and with some instruments is so slow that you feel the process of the sound production as if on slow motion and after that the decay is very fast, abrupt, no natural echo, no lingering. So, I feel how the drum is hit and the canvas flexes and it continues unnaturally long (as if you are listening to a tape recorder that has loose belt on the wheels or it plays on batteries and the batteries are already on 10% and suddenly it dies. This is also very annoying with piano – sometimes I hear the piano key going done for too long and abruptly its sound dies. And this is happening also with some vocal performances – you know the performance and you know that the singer is prolonging a particular word, syllable, note but that is missing - it dies abruptly like in no other headphone. The slow attack, the fast decay and the lack of details and resolving capabilities, put together, ruin anything good that comes with the Eikon for me. On top of that, imagine that also the stage collapses when song is fast and busy - that is the end, I do not ‘buy’ all these in exchange for wooden caps, boutique production, a nice plastic case, and after waiting for months.

I know that all I shared above is scandalous for some ZMF fans, I know that I will be called greenhorn (just another new head-fier), that I do not understand anything and how big are Zach’s achievements, that I have ill ears or that I am rambling and sound like a hater. Well, you may say these but this will not change my attitude for the Eikon, unless suddenly they do not get some kind of a transformation for better.
All in all – Eikon is fancy and probably someone with tons of money will accept all the negatives, that my set has, just to say he/she has the set with the best timber performance or for the wooden glossy caps and solid build. Not me! For me the Eikon doesn’t worth the money in 2021/22, not this set that I got and that package (by package I mean something bigger). For me they are like my vintage headphones from the end of last century with which I was not lucky. I would dare to say that I enjoy far much my Pioneer SE-205 (pads changed to thicket ones) that doesn’t have the quantity of bass of the Eikon but has far better attack, well presented natural mids which are slightly forward, has some sibilance on specific performances but is far more detailed and has big sound stage like DT770 pro; I also like more my Beyerdynamic DT48a that is better in everything (not that much quantity of bass again but far enough to be neutral and very precise) and has supreme resolution and timber. Practically for the money that I paid for the Eikon you may buy, according to me three better headphones with guaranteed FR and performance) and even stay with some change. For example:
1/ Mid-price set that is fairly neutral: Creative Aurvana Live! SE + Focal Listen Professional + Fostex T50rp Mayflower V1. Hear you need some mods: the CAL! SE should get a mod of installing Dynamat inside the caps to kill the vibration of the plastic caps; the Focal Listen should get quality perforated sheepskin ear pads; the Fostex T50rp Mayflower V1 should be produced properly and without installing the thick stiff felt that sticks on the driver since that makes the treble too piercing. So with these triple set you have: 1/ a biocellulose driver headphone that has mild V-shape signature, more bass, better bass and sub-bass, treble has more resolution but the vocals are slightly recessed and the treble not that smooth; 2/ a Focal that has high price/performance value very high and it is with neutral bass, well done vocals that has nice forwardness plus smooth and detailed treble; 3/ a planar that is well-know for its price/performance value, versatility, mod options and is bright neutral; 4/ all of them are having consistent sound stage and the T50rp a wider one.
2/ Above mid-price set that is fairly bassy but has more value and better performance: Fostex T50rp Argon + Focal Elegia + Fostex T60 Argon suede pads or the Denon AH-D5200. I think I do not need to explain what you get from the T50rp Argon since it is well known; from the Elegia you get fairly neutral set with very well-done mid forwardness and very pleasant and detailed mids and treble (as I shared above, the Elegia replay is like big speakers in a fairly big room); the T60rp, being also ‘boutique’ mod are better in anything vs the Eikon, except for the natural vocals, still they sound very natural for a planar, and if you roll pads you get different sound signatures. I enjoy all the three headphones very much, they complement each other very well, you have wood, durability, finesse. Just to remind the Fostexes need more power than the Eikon and the Elegia needs quality cable (Litz, for example from Customcans UK).
3/ ‘Expensive’ quality set with fully different sound signatures: Sony MDR-Z7M2 + Focal Elegia + Beyerdynamic DT1990 pro. All these three cans are DD (so, please, no planars to be blamed for!) and all these three cans are very well built and solid and are far more comfortable than the Eikon. You have a top-end Sony with 70mm driver (just below Sony’s TOTL Z1R) that has superb bass, acceptable mids, well done treble, that has high resolution, wide sound stage (that beats even some open headphones), even has some holographic qualities and the comfort is superb (one of the best). The Elegia I already described, so to the DT1990 pro – I know these are polarizing but as I said above the 8k peak can be easily killed without loss of detail and they come with two set of earpads that change the sound frequency in the lower end, they are very solid construction, comfortable enough and are top cost/performance value. You can find any of these three cans for around $500 and some of them even below, so you nearly pay the same money but do not get just one Eikon.

If I have to choose just one phone that is close to Eikon in the sound signature I would always go for the Focal Elegia and will always take the Elegia over the Eikon I have. The Denon AH-D5200 is also a much better choice (with it you have a bit less forward mids and vocals and better textured bass and better sound stage) and the Focal Radiance is also an option but it has a bit more bass than the AH-D5200. And this is only the close back headphones. If I put in the rivalry openbacks – ooh, the options are far more.

I am fully disappointed by the comfort with Eikon and service I got. I got the Eikon on Friday, noontime. So, after 5pm I started eagerly using it and I couldn’t accept its staging and slow attack and lack of details in the low end. Also, I have and issue with the construction – it is a heavy headphone and it is equipped with a leather strap that has to provide comfort – you know how Audeze and AKG headphones are build, they have the leather straps installed in a way to provide space between the strap and the main metal arch, these straps keep the headphones floating on your head and the metal arches do not touch your scalp and that alleviates the weight. Well, my pair is having a leather strap that is too long – it is following the shape of the arch, sticking to it. I tried all kind of shaping for the arch – oval, angled in the middle, oval and angled in the middle and close to the caps to avoid the metal arch pressing on my head because is giving me a lot of pain. The hot spot I get for one hour of using the Eikon stays the whole day, it is highly uncomfortable – my neck doesn’t get tired, but my scalp hurts a lot. So, on Monday, after three nights and two days I wrote a mail to ZMF asking how the sound signature and performance are expected to change if I switch to the perforated pads that I ordered with the Eikon, and also I explained the issue I have with the strap and asked that they send me a shorter strap that will secure some space between it and the metal arch for better comfort. Now, it took them 5 days to reply – I am in 14 days return period, but they replied on Friday evening. I can say that even Aliexpress reply faster, and if I speak about boutique and mod companies like Lawton, Mayflower, Customcans – they reply latest next day.



And what was the reply:
  • on the ear pads they said “Generally, we do not recommend using perforated pads with our closed back headphones…”. So, on the website and in the leaflet in the case there are perforated ear pads that are shown to be used with the Eikon but when you ask they do not recommend it;
  • on the issue with the strap, they said “… Once you put the headphone on your head the leather strap should tighten as the chassis is opened to provide cushion and space between the head band. Below I have linked an instructional video on how to bend your headband to get an optimal fit. If you find that is not giving you the results you are looking for, I would recommend trying our suede strap. The suede strap is a little thicker than our leather strap. It provides a little more cushion and may help alleviate the hot spots you are experiencing. I have also linked the suede strap below, as well as an instructional video on how to install our straps.” I was shocked since: I have attached photos and it is obvious that the strap is too long. I explained that to them and they say cannot be; but they also say that if I do not get the result I want I have to buy the suede strap that ‘MAY help’ – come on, your client is not satisfied, he doesn’t have the comfort to use your product because of a flaw, he proposes a solution that cost peanuts but you tell him you have to buy something else that ‘MAY help’ – OMG! And all that after: a/ I paid in advance despite the long production lead; b/ I had severe customs complications since the order ZMF confirmed to me was in Euro and the PayPal payment is in Euro but ZMF did send the shipment with an invoice in US dollars (do you know how fancy is to discuss currency conversions with Customs officers and write additional papers!?); c/ I was given in a mail a shipment deadline that was not met and ZMF prolonged the product nearly to the full end of the grace period they have. This is not the service that should be provided for a $1400 headphone.
  • After sending a feedback email with my disappointment I received 3 sentences reply and one of it is: ‘Sorry for any disappointment, we do not control customs and don't have a dedicated support department as a small business that handcrafts headphones.’ Absolutely irrelevant.
So, what stays for me is the hope that my Eikon performance will go through a transformation for better and that I will find a solution for the severe hot spot or meanwhile my scalp will build enough padding itself.

Well, today, 27.02.2023, I add this: since one week the ZMF Eikon replay transformed to far better replay. And saying far better I mean a replay of a closed back that is hard to beat! But that replay happens only when sourced by my new Feliks Echo 2. The replay by the Eikon is highly satisfying in musical and technical aspects but only from the Echo 2.
So, a nice pair that worths $1400 bucks :)-), after I got an amp for $800!!!
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Glad I saw your review. You basically mention everything I would dislike about a headphone. Ancient technology, heavy, uncomfortable, customs.