Kefine is a new audio brand out of China that have launched a couple products to market. This review will take a look at their dynamic driver IEM, the Delci. The product was provided directly from Kefine for reviewing.

The Delci features a 10mm Polyurethane + Diamond-like Carbon (DLC) driver within aluminum gunmetal gray shells. The product is $59 and available on various online retailers.

The product also comes with a very nice cable that is a 4-wire braid mixing 2 wires of light copper with 2 wires of dark brown color that gives the cable a bit of a unique and luxurious look. The connectors are all aluminum and match the IEM shells, while terminating in 3.5mm stereo jack and 2-pin connectors.

Sound Impressions​

Kefine went with a very warm and balanced tuning choice with the Delci and its tuned quite well, with a fairly smooth and lifted bass range through the mids. The upper mid-range and treble are very easy to listen to, but there is a small peak in the mid-treble that only sometimes peeks out to be sharp on some cymbal attacks. Overall, the tuning is very nicely done and can be considered a gentle V-shaped tuning.




The low end is quite punchy with good impact. The dynamics are quite lively on Daft Punk's Fragments of Time, and surprisingly handles this track very well. Cymbals don't sound too bright and the busy passages are well controlled as is the bass section. The Delci's texturing may not be the best here, but it's really great for a budget IEM.

On a rock track like Vatican by Laterns on the Lake, the haunting lead vocals come across very clear and the echoes of Hazel Wilde's voice as it disappears in the background whisper away on the Delci. Again, I am very impressed with how smooth and engaging this IEM sounds with this track. Like on Daft Punk, the drumming from Radiohead's Phil Selway is punchy, and provides a good kick when needed.

I also tried a bit of piano jazz with the Delci, listening to the live recording of Bill Laurance Trio at Ronnie Scott's. On "The Good Things", the IEM was able to handle all the most intense parts with Laurance's piano melodies in full swing, and the electric bass guitar strumming heavily and drums on high octane. Kick drums are heavy on this track and the Delci had great impact when they struck. The soundstage felt more intimate overall, like I was sitting in the front of the show, but surprisingly did not feel like it was overwhelmed with poor separation here.

Final Thoughts​

The Delci is a great single DD IEM from Kefine. It's tuned very well to my preferences, and works well with all the genres I threw at it. I am pretty impressed with the sound for the low price of just $59, and this easily becomes one of my recommendations at this price point. If I were to change anything with it, I'd consider lowering the treble slightly after 7KHz to reduce it for those who are more sensitive to brightness, but overall this tuning works well.

---

Simgot's EA1000 "Fermat" is a dynamic driver IEM that features 2-drivers, one of which is a normal powered dynamic driver, and a second one being a passive radiator. While passive radiators are commonly found in desktop powered speakers to get a bass impact response when typical smaller speakers can't achieve it, there's only been a small handful of IEMs that have only recently started adding similar ideas into an in-ear monitor.

The EA1000 sells for $219 USD and is available at many retailers including Linsoul and Amazon and AliExpress. The product was sent for review directly from the manufacturer.

Simgot gets a lot of kudos for their presentation of accessories here. The included light gray polyurethane-leather case is really cute and small, but fully functional. It has a magnetic closing flip lid, with enough space for the IEMs and a small pocket for the detachable filters and other small accessories.




The included cable is a matching silver/white 2-wire cable that terminates in chromed-aluminum 3.5mm jack and 2-pin connectors to the shells. There is subtle color in the way of the gold-chrome chin strap hardware, and a very subtle rose-gold rim along the faceplate. It's otherwise a very minimalistic and white-out look that I think looks really great.

Simgot is really big into the filter game, and they've included 3 pairs of filters that change the tuning ever so slightly. The default setting is a chrome/red nozzle, with an additional set of chrome/black, and gold nozzles included. The red setting is my favorite of the bunch, while the black is just a tick more upper-mids/lower treble. The gold adds even more upper-mids and makes it more forward sounding and was my least favorite.

Sound Impressions​

The EA1000 has a slightly U-shaped sound that almost enters in V-shape territory with a bass range that has a slight focus in the mid-bass, and a slightly recessed mid-range followed by a slightly uneven treble range that changes depending on the filter of choice.




The key feature of the EA1000 that I really liked was how dynamic it sounded with good impact and punch, while also providing a very clean presentation. It's perhaps a tad thin despite having an elevated mid-bass, and that's likely due to the faster-sounding driver and focused energy in the treble range.

That aside, it does lend its way to having good imaging and sound separation, and I was surprised by a lot of the technical aspects of this IEM. It could use a tad more meat in the bones on some tracks, but it's still more than enjoyable.




On some female vocal tracks, such as Maeta's Cool Cat, there are some occasional highs that can be a little abrasive and its not quite as smooth as I'd like playing it out of the Hiby R3 II audio player. With the Fiio M15S, this is tamed down a bit though, and I really enjoyed the pairing of these two. Once I enabled my preferred MESB setting, the Hiby R3 II's treble sharpness did subside enough though.

All of that taken into account, I found the EA1000 Fermat to be a nicely tuned IEM that can perhaps be a tad bright on some notably treble-heavy tracks, but it has surprisingly good technical chops that I don't think I was really expecting given what I would have considered a gimmicky Passive Radiator driver and a single DD.

The PB5 Osprey is a balanced Korg NuTube portable headphone amplifier made by iBasso and is comes out at the same time as their new D16 1-Bit portable DAC. Since I already owned the DX320 Max, I only purchased the PB5 and used an ownership discount to get the product at a lower price than the $1599 retail price of this unit, which sets out to compete with Cayin's C9 NuTube portable amp and others.

I reviewed the C9 a while back and enjoyed its smooth and enjoyable sound, but disliked how bulky it was. The PB5 is a bit smaller and much lightweight. It's actually surprisingly lightweight, especially without its included green leather wrap-around case. This makes it more portable and more transportable, although it is still thick.

Dimensionally, its very similar in size to the DX320 and DX300 MAX units, in all aspects, and shares similar width and length as the Fiio M15S, but double it's height. This makes it easily stackable with either of the DAPs I use.




The PB5 comes with a bounty of accessories, including 2 sets of 4.4mm to 4.4mm balanced connectors for input/output connection from your source to the amp, the green leather case, a carrying bag, and USB cable. The PB5 cables have a very unique bullet-looking connector shape that I've only seen iBasso use and make and makes it stand out.

There is a downside though, as the larger shape of the connector head makes it sometimes difficult to turn the adjacent volume knob. The knob takes on the same stepped attenutation feature of the 320 Max here, which I found quite annoying. It's slightly less annoying here for whatever reason, but it still cuts in and out when changing volume and can also be stuck between steps causing imbalance.





The other annoyance I found is that USB Charging only works with standard USB-A to USB-C cables. USB-C to USB-C cables and power delivery or even quick charge sometimes don't work. It likes to get old skool power feed. It also will automatically shut-off charging as soon as the battery levels max out, and then start to drain battery even while charging. I'm sure this is a feature to prolong battery life, but I also wish there was a way to bypass the battery altogether, or have some sort of smarter feature here to keep it plugged in and going.

You can, however, unplug and replug the cable after it's started to drain and it'll start charging again. To combat this feature, I ended up buying an in-line on/off switch for my USB-C cable so I can just toggle it on/off to start charging again without having to replug it each time.




The other thing to note on this device is that it is balanced input only! That means you'll need to use a source that is capable of feeding it sound via 4.4mm cable, whether that be using the included 4.4 to 4.4 cables or by an adapter for XLR to 4.4mm or some other connector of your choice.

It does, however, output music to both 4.4mm balanced and standard 3.5mm stereo, so you can use this with any headphones or in-ear monitors of your choosing, or output it to an amplifier, powered speakers, or whatever you want.

Sound​

When I first put this unit on, I was met with an overly bassy and partially muddy sound. It was overwhelmingly focused on the low end, but after about an hour, the Korg NuTubes seemed to have stabilized and it was much cleaner sounding, but still featured a deep subbass boost from what I normally listen to. That was the part that definitely stood out quickly when paired with my neutral monitors, the Subtonic Storm IEM.

It was so much of an effect that I had to measure it to make sure I wasn't just fooling myself. After measuring it on the Storm, the Dunu Zen, and the Tin T5S, I discovered that there was a bass shelf added to the system that started around 100Hz down to subbass regions, with about a 3-5dB addition.







This, coincidentally, was what I had been toying with on my Subtonic Storm recently -- seeing what a small bass shelf addition in the 20-60Hz region would do and I ended up liking the results quite a lot and had been playing with this EQ lately. With the iBasso PB5, I no longer had to mess with software EQ, as it made almost the exact same EQ naturally.

It's not just a bass quantity boost though. The amplifer also added a more 3D holographic space and with a touch of additional upper treble air. These are things that weren't measurable in a simple FR graph, but it was something I heard in comparison to just listening to either my iBasso DX320 Max or Fiio M15S without the amp connected.

Adding this extra layer of bass and imaging may not work with all headphones and IEMs. With the already bassier Sony MDR-MV1 headphones, I didn't necessarily feel like it added much, and only made the bass levels more than necessary. With the Unique Melody MEST MK3 IEMs, I felt the darker tonality was heightened with the PB5 amp and it's already forward soundstage made smaller for some reason.

It does shine with more balanced and neutral-tuned products though, and I absolutely love the extra fun-factor it adds to the Storm and the Dunu Zen. These two products really benefit with this amplifier, given them an extra oomph to bassy tracks, and smoothing out the treble even more.

Final Thoughts​

The PB5 was an amp I wanted to test out at a discounted price and I've been very happy I've tried it. It's been a wonderful new addition to my semi-portable audio chain and one I take with me to work everyday to use. It's a perfect pairing with the Subtonic Storm and the Dunu Zen IEMs, and is definitely something I recommend to check out if you are interested in adding a more punchy and dynamic amplifier flavor to your current audio chain.

The Neo Stream is the current flagship streamer from iFi, and is sold for $1299 MSRP. The Stream is a significant upgrade over their previous Zen Stream device and this review unit was sent to me directly from iFi to take a look at.

The Neo Stream comes in an all-aluminum metal chassis, and in a relatively small package. It's larger than the Zen series, but is significantly smaller than a traditional audio component, and takes up about 30% of the space of my Holo Audio Spring 3 KTE DAC or Holo Bliss headphone amplifiers, which are the traditional ~17 x ~12 inch width sizes of normal full-sized audio devices.

The Neo Stream is meant to be a desktop device, and can be placed horizontal with included feet, or placed vertically with a base stand included in the box. For most of my testing, it made the most sense to place it horizontally on top of my Holo system, but for many, the vertical stack on the desk may provide the best space savings, and it would fit neatly next to a desktop speaker. It also pairs perfectly with the Neo iDSD or iDSD 2 all-in-one DAC & Headphone Amp, as they use the same chassis design.

Input/Output​

The front of the device has a small display screen on the left side that can display album art and information, as well as displays the menu and options. The center of the front panel has a large multi-functional knob that controls volume and scrolling through menu options. On the right side are a menu button and a power button, as well as a USB-C input.



The back of the device has a large array of input/output options. For inputs, there is an additional USB-A input, and ethernet connector. There is also an optical to ethernet adapter in the box as well for those who want to use this functionality. In addition, there is an included Wi-Fi antenna, which is my preferred option for input signal.

On the output end, I2S (HDMI), S/PDIF (Toslink and Coaxial) as well as AES/EBU outputs are available. There is also a USB-A output to DAC included too.

Finally, this NeoStream also has a custom DAC built-in that can also output via traditional stereo RCA and a 4.4mm output for those who want balanced output. Most users who use this option will need a 4.4mm to dual XLR 3-Pin cable to connect to your speakers or amplifiers.

Device Usage​

For my configuration, I used wireless Wifi to send data from my Roon Core server to this device, or via my iPad using Tidal Connect or Airplay 2. There is also option for Spotify Connect and DNLA. The Neo Stream was connected to my Holo Spring 3 KTE DAC using I2S connection, and also directly to my Holo Bliss Headphone Amplifier using 4.4mm to XLR balanced connectors. I connected directly to see how the internal DAC performed, but more on this later.

The initial setup of the device was fairly straight forward, as long as you follow the manual. Once you plug it in and power it on, you'll want to move the menu option to enable the Hot Spot mode. This allows you to connect your computer, phone or tablet, to the Neo Stream's internal hotspot network. Once there, you can assess the setup page in your browser and configure it to connect to your wireless network.



After that, I was able to quickly find the streamer on my Roon software without any additional work. This device is Roon Ready, so that makes it a breeze.

Sound Quality​

For sound impressions, I tried the Neo Stream in both digital and analog output. In the first scenario, my Roon Server sent music via wifi to the iFi device, and I used I2S to send to my Holo Audio Spring 3 KTE, and from there, it was XLR to the Holo Audio Bliss headphone amplifier to my Hifiman Susvara. That's a lot of H's and I's in one paragraph!

I turned on Nanna's How to Start a Garden record from 2023, and right away, I was impressed by the clarity and slightly forward sound of the Of Monsters and Men vocalist. Nanna's voice was delicate and resolving, and the Icelandic vocalist's breathiness was captured quite well in this setup. I wouldn't have expected less, as I would prefer to have as transparent of a sound as possible from a streamer who's job was to only to be a digital transport.

I enabled Group mode in Roon with the Spring 3 on USB and also connected to the Neo Stream and swapped back and forth between inputs to see if I could hear any significant or appreciable differences between with and without the digital streamer.




The one thing that caught my eye was the trailing end of each line of lyric on "Disaster Master," my favorite track on this record. The Neo Streamer has just a touch of a brighter edge to these notes, and a generally brighter tonality throughout. It's subtle, and perhaps borders on the sibilance if given the right track, but this provides that sense of clarity to the track.

The rest of the tonal curve seemed fairly inline with and without the streamer in the chain.

Interestingly enough, these trailing high "spots" didn't seen to present itself when I swapped to analog out -- sending signal from the Streamer through its built-in DAC to my Holo Bliss headphone amplifier, bypassing the Spring 3 altogether.

In this configuration, it seemed less bright than having it connected through the DAC, but it lacked the depth and felt a little smaller in stage than with the R2R Spring 3 KTE in the picture. This felt very much clean and neutral, with a slight touch of warmth and body that I believe the Holo Bliss provides.

Comparing this to a normal DAC such as the SMSL DO300SE that I use primarily at work, or any number of dongles I have at home, I find the sound output from the Neo Stream DAC to be resolving and well-tuned and balanced as a neutral player. It doesn't sound as bright as some of circa 2020-2021 iFi products which I disliked, but has a sound that is more aligned with their recent offerings which are neutral but not too bright.

Wrap-Up​

In my current setup, which is a bit more unique than others with an R-2R DAC in the chain, I find the Neo Stream added a tad of brightness to the system that was not present when I went directly to the amplifier itself. This was a bit strange, since I don't hear this same brightness without the Neo Stream, but that could just be a setup synergy thing too.

The Neo Stream was fairly easy to setup and operate, and is well-built. The screen is a tad small for my taste, and I wish this device came with a remote, as it operates kind of clunky through the front panel knob and buttons.

Other than that, it's provides strong clarity, and neutral tonality, and has a ton of input/output features that makes anyone deep into digital audio a very happy person with many choices.

One of the cool things I've been able to witness in this audio hobby is the growth of an idea within the community and seeing it blossom into a real thing. I've seen many community members take their ideas and make one-off projects, and some make commercial products that have become successful. I think of brands like ZMF for the latter, and my audio friend Phil for the former, the Aurorus Australis and Borealis, or the now discontinued Prisma Audio Azul IEM.

Today, I am sharing another community experience - one that is even closer to my heart, as Subtonic, the brand behind the Storm, were once members of the Audio Discourse family, and co-hosted a years worth of podcast and YouTube content with me.

The evolution of these community members, Leneo (Ken), Toranku (Cornelius), Valoncia (Kevin), and Chang: from their audio forums and Discord channel discussions, to inventors and to full-blown commercialized company owners has been quick and awesome to see, and now I finally get a chance to hear their first product -- the Storm.

Launch Edition​

I purchased the Launch Edition directly from Subtonic, and this is not a review unit. In fact, they did not send out any review units, loaners, or anything, and pretty much have been selling based on word-of-mouth and limited forum exposure. The Launch Edition sold out at 50 units, and they plan on releasing a "normal" version in the near future. The pricing is currently unannounced, but the Launch Edition was sold at $5200 USD.






Subtonic partnered with Symphonium for their manufacturing expertise. I've also had the opportunity to demo and review many of their products in the past -- IEMs such as the Helios, Triton, and Meteor have all been really solid at their price points with my only negative being the fit. And that was one of the things I was slightly concerned about with the Storm. It was oversized to fit all of the 9 drivers they crammed into it, along with cross-over network components and other gizmos they threw in there. So, as someone with small ear canals and generally having harder time to fit IEMs than some other reviewers, I was very hesitant on buying this.

Luckily for me, I was able to test my ears with a set of Storm 3D-Printed mock-up shells. To my surprise, it was an insanely good fit. In fact, the whole thing looked very reminiscent of my Hidition Viento Custom IEM, which blew me away.

I was quite worried that with a larger shell, and the not-so-good fit of the prior Symphonium Helios, would steer me away of something I had a good feeling about, but I was saved by this new shell the team designed. It fits me PERFECTLY. As close to perfect as it a universal can be -- this is the most comfortable shell design I've worn yet, and it is also the biggest one -- making the Empire Ears Odin look small.



UNBOXING


The Launch Edition comes with titanium shells and hand-painted gold and black enameled face plates that has a cloudy storm motif. It's absolutely stunning and an eye catcher. I wore this around work and my cubicle mates were quickly impressed with how well-designed it is (both visually and its construction), which is saying a lot coming from a team of materials, manufacturing, mechanical design, and structural engineers.

The cable included with this Launch Edition is the Nightjar Acoustics (also owned by Subtonic member, Chang) Mira 2-wire cable. It's fully-shielded, but still very lightweight. It's probably a tad stiffer than I like, but still very maneuverable, unlike the recently reviewed UM Mest MK3 cable from PW Audio. The cable is an intricate weave of copper and silver-plated copper and has metal copper colored Y-splitter and a NightJar branded chin strap.

The version of the cable I chose with this Storm also has OE's Multi-Plug source connector, which lets you swap on 3.5mm, 4.4mm and 2.5mm jacks for various sources. There is also an optional USB-C and Lightning add-on jack you can get directly from OE.

This version of the Storm also include an extremely well made green leather zippered case from another Singaporean boutique called Todah. This case is on the larger side, but it is luxurious in both feel and looks, and can fit a lot of accessories and even a dongle with the Storm.

Sound Impressions​

How does the Storm sound?

The Storm is good. It's actually great. No, it's actually the best IEM I have heard, and it's actually not even close. I am not saying that as a friend of the team, I am saying that as unbias as I can be, and even my scientific squiggly side of the brain can even show that with the FR closely matching my preference target(s).

In fact, I would dare to say, I prefer this over my Hifiman Susvara headphones, which is at nicely settled at the very top of my list of all personal audio gear. The Susvara, as some may know, requires a lot of current and power to get it going, and funny enough, the little tiny Subtonic Storm also has outrageous power requirements. Its sensitivity rating is just a smidge higher than the Susvara, and is significantly "quieter" than most headphones and IEMs out there.

What does this mean? It means you need to turn up the volume to get this as audibly loud as any other typical headphone or earphone you probably own already. Is it crazy levels? I don't know if I'd go as far as to say that. I definitely think the Susvara and HE-6 require a lot more amping power to get loud, but the Storm's power constraints may cause some problems for folks.

For example, due to its low sensitivity and low resistance, it does draw more current than normal, and this can put a drain on batteries of your phone and portable audio players. In my case, I couldn't use it with the power hungry iBasso DX240 audio player, which itself drains battery relatively fast with its Android operating system, Roon Arc running, and its flagship desktop DAC and discrete amp topography. It's a small player with a small battery and now you throw in a super power hungry headphone into it, and it's draining 1% per minute! Yikes!

But don't fret too much. With the tiny Hiby R3 II, which runs its own custom OS (not Android), the battery drain is much more normal and it'll last quite a long time.

For most of my review, I listened to the Storm with a series of players including the DX240 and Hiby R3 II as mentioned already, along with the gigantic iBasso DX320 MAX digital audio player, the Holo Audio Spring 3 KTE and Bliss KTE desktop DAC+Amp units, and the SMSL DO300EX DAC/Amp combo unit.




The Storm hits a perfect balance of weight and delicateness, while also providing great rumbling sub-bass and a good sense of treble air and extension, all while also giving a good medium-sized soundstage. The Storm was tuned to my specifications, even if I was not part of the design process.

I somewhat knew what I was getting myself into with a total blind-buy of this luxury item. I had spoken with Cornelius and Ken about audio and tuning preferences for a couple years prior to this product's launch on a daily basis. Toranku (Corn)'s preferences align very closely with mine, and our iterations of "preference target curves" have always been tightly matched with some subtle differences over the years.

This made it no surprise that I would enjoy and instantly fall in love with the Storm from the moment I put it into my ears, turned on Slowdive's latest record, "everything is alive," and let the music melt into my ears and into my brain with euphoric bliss.





While it's quite obvious I absolutely adore the tonality of the Subtonic Storm as it's frequency response matches up with my target curve quite well, the technical aspects and the little intricacies of the audio presentation from this all-BA+EST setup is really shocking.

Percussions sound awesome with the Storm. Drum kicks have great thump and punch, but is precisely controlled. Bass guitars have a lot of power and depth. I listen to a lot of jazz-trio music and drums and stand-up bass guitars provide 2/3rds of the music and control the flow of everything. The Storm is fantastic for this genre, as it can exhibit the power of the bass guitar, the precision of the drummer, and the melodic ease of the piano player and without any exorbitated forwardness and "shoutiness" that many IEMs face when the piano-led music I listen is fully up-front.

The Storm works well across many genres. I listen to it on my eclectic mix of music - everything from the aforementioned shoegaze music of Slowdive, to the jazz trios of Tingvall Trio and GoGo Penguin, to the country rock of Jason Isbell to strings-led orchestra pieces and bluegrass jams to the alternative classics of the grunge-era late 80s and 90s that someone growing up in Seattle during that period must love.

And I've enjoyed blasting The Roots collection of hip hop masterpieces on the Storm. The punchiness of the presentation really make ?uestlove's beats stand out.

Back to the shoegaze-genre a bit: Slowdive's "Kisses", a track with a steady drum beat, powerful bass section, and the signature ambient and dreamy guitar riffs that made the band legendary in the genre, sound majestic on the Storm. The presentation is allowed to breathe with an open soundstage that lets each instrument lay down its own thing and it all comes together in a very well-layered and deep soundscape that flows cleanly and without any distraction. It just sounds right.

Sources​

I have tried the Storm with a lot of different sources. I'll do a quick, very quick, run down of how I felt the Storm performed on each of these devices.

iBasso DX240 with AMP8MK2 SE​

This is a really good combination. The DX240 features the ESS9038PRO DAC and the AMP8MK2SE is my favorite of their discrete amp modules. It has a nice balance of technical performance and warm pleasing tuning. This one is a tad softer than other sources with the Storm, but it provides wonderful euphonic characteristics and great layering and depth.

The DX240 with this amp does drain battery pretty fast, and even faster with the Storm. I was probably going on empty in a couple hours with Roon Arc streaming.

iBasso DX300 MAX and iBasso DX320 MAX​

These two giant DAPs provide the Storm with ample power and battery life. The DX300 MAX is not one of my favorite tunings. It works but is a tad too neutral and maybe a smidge bright. While that works with the Storm, it's neutral avec neutral and while it doesn't color the IEM in any way, once you hear the DX320 MAX, it's a different ball game.

The DX320 MAX features 4 ROHM DACs which add a whole new flavor. It's rich, warm, yet very, very well defined and its bass texture is above all others and it shows with the Storm. This combination really lets the Storm shine through.

Apple USB-C Adapter / Apple iPhone 5SE Gen 1​

The Apple Dongle paired with an Android phone is not nearly enough power. It barely gets it loud since for whatever reason the Apple Dongle is gimped pretty hard with Android devices. The iPhone SE features a pretty much similar sound to the dongle, and I think it works well with the Storm in theory, but the lack of power makes it not the best combination for a power hungry IEM like the Storm.

FiiO M15S​

The M15S is one of my favorite FiiO devices. It also features the ESS9038PRO DAC that the DX240 does and the same kind of warm euphonic characteristic to it that you can customize even further. I felt this is a nice balance to the Storm's incisive attack, and while it does tame down the general dynamics of the IEM, the added coloration makes the Storm sound great to my musical playlists.

When I turn on Desktop Mode and Ultra High Gain, bumping up the power, and then turning on All-to-DSD -- all while not draining any battery -- this really makes the M15S sound like a great and wonderful pairing with the Storm.

iFi Diablo 2​

I only just received the Diablo 2 and I have a lot of personal gripes with this product and iFi in general, but it actually matches alright with the Storm. The Diablo 2 is a tad bright, and because its gain levels are super high, even the Storm requires all but a small twist of the knob to get very, very loud, even on lowest gain setting. Flipping the IEMatch feature on seems to kill some of the dynamics and punch of the Storm, and so I have to leave it in normal mode, and use a 4.4mm to 1/4 inch adapter to make the Diablo 2 useful. And when I do, I do like what I hear. Its clean and clear, and has decent dynamics.

iFi Go Pods​

I tried several true wireless adapters with the Storm and none of them could get this thing singing nor even get them loud enough at full volume. The Go Pods definitely can, and they are the best sounding true wireless adapters I have found. The do work well with Storm if this is what you want. I didn't like the long-term comfort of using them, and the buttons are tad too sensitive, but they work.

Hiby R3 Gen 2​

This is my current ultra-portable solution. This tiny little R3-II by Hiby can surprisingly power the Storm without too many compromises, and retain very, very good battery life. In fact, it probably has the best battery life of all the devices I tested here.

The Hiby R3-II has a warm signature and that is something, as you have probably already read from above, I like with the Storm. It has decent dynamics, and generally isn't missing too much information. It could use a tad more air to show off Storm's treble extension better, but overall, this is a nice portable DAP that I was happy to find works with the Subtonic Storm.

Hiby M300​

This is the latest Hiby ultra-portable: this time with Android OS 13. It has good battery life and maintains it fairly well with the Storm and streaming. It does help that this device does not use a balanced architecture and therefore uses less energy. The M300 is very neutral, but not sterile. And this Storm pairing gives it a very dynamic and punchy sound, while leaning a tad brighter than the rest of the ones mentioned above.

Cayin RU-6 and RU-7​

These two unique Cayin dongles feature R-2R and 1Bit DACs that are much different than the competitors. The RU-6 is a very smooth DAC and perhaps smooths over the Storm's intricacies too much, but it also gives a very lush sound. It's almost the anti-typical Storm sound, but it melds it into something kind of pleasing. I can see some hating it though. I actually like it a lot.

The RU-7 is probably what people were hoping the RU-6 would be like. It matches better with the Storm, giving it the higher resolution and punchy sound that the RU-6 strips of it, while maintaining and laid back sound.

Holo Spring 3 KTE and Holo Bliss KTE​

This pair of copper Holo Audio units makes up my desktop unit I normally use with the Hifiman Susvara -- a headphone that requires ample current to get going. The Storm is like the Susvara for IEMs in this regard, and while it doesn't require the same amount of headroom, it does need more than the average IEM. This desktop system has way more juice than is needed to get the Storm going and I really like the balance of its warm and resolving sound with the Storm's technical prowess and tuning.

Final Thoughts​

I can probably go on and on with the Storm's greatness, but that could take a long time to write up and I'd just end up blabbering on without no end...

Instead, what do I not like about the Storm?

It cost a pretty penny. It's expensive. Very expensive. And yet, there are lesser IEMs out there that cost more, and sometimes magnitudes more! I don't know what to say here, besides, it is not a cheap product, and the cost to performance ratio is probably realistically low. But that said, I love it and I am very glad I spent the money on this luxury item because I use it all-the-freakin' time, and it's made me less and less envious of the next new thing. In fact, I have practically zero interest in new IEMs at this point in-time, besides what is on my review queue.

The Storm has made me a new and better man, one that could quit audio (defined as the ever-lasting urge to listen to more "things"), if he wanted to. I can now just enjoy the music for what it is, and being fitter, happier, and more productive at the same time. The End.

I've always deep down in my heart wanted to enjoy a big bassy headphone or IEM. The problem is, most of them are not very good. They are muddy, boomy, and very poor in resolution, and to balance it out, they make highs very bright, or even worse -- have no treble at all (i.e. L-shape). While there are some fun bassy sets like the Empire Ears Valkyrie and Legend X sets, they are quite pricey, and also can be a tad harsh in the highs.



Along comes Fat Freq. This is a Singaporean small boutique brand that makes a series of IEMs with big bass boosts, but with balanced mids and treble. I was enamored with the frequency response graphs I had seen from various measurement sites when I first heard about their Maestro series. They had huge bass boosts, but the mids/treble range fit right along what I like.

So, I dialed up Precogvision, and asked him to send me Fat Freq 'scheapest universal set, the Maestro Mini, since I knew he had recently reviewed it. After receiving the unit, I must say, it does exactly what I was expecting it would do. Hit bass hard.

IEM Design​

Since this was a loaner, as well as a pre-release unit, I did not have all the retail packaging and can't provide any details here. In addition, the nozzle of these units do not have a filter on them, and the driver and inner cavity of the Maestro Mini is exposed. Removing the filter may cause some sound changes.

The MM itself is a small-sized blue IEM with a very comfortable design that I found good and easy to wear. It features standard 2-pin connectors on both sides, and a FatFreq logo on the faces.

Sound Impressions​

After listening to a bunch of neutral monitors, or slightly bright gear with light or even bass boost, and then putting on the Maestro Mini, I was immediately engulfed in deep, rich and thick bass. It was startling at first. I knew I was expecting a big gain here, but it was surprising how much it was in some songs, yet how it did not come off as muddy or bloated. It was bass quantity done right.

That's because the FatFreq brand decided to bump a downsloping HUGE bass bump starting at subbass regions, making it act like a subwoofer, and not a mid-bass woofer, which can add a lot of kick and punch, but also bleed into the midrange. With this amount of bass increase, 20 decibels above the midrange, you really need to be careful how this tuning can affect the overall tonality.

The Maestro Mini, for the most part, does this quite well. So, normally I talk about the general sound, but it's taking me three paragraphs to get to the point. This is a big bass in-ear monitor that has surprisingly well balanced mids and smooth treble. There are sometimes hints of a some brightness in the upper-midrange, and that could possible be attributed to the filterless design of this prototype. In production models, there is a nozzle filter, and that may tame the brightness a tad.

How does the Maestro Mini do technically? It's alright. I would say it's average. There's nothing wrong with it. There's nothing special about it either, besides its not-so-secret weapon of big sub-bass, and in this regard, it does it very well. It's not the most detailed IEM at the $450 price range, and its not blobby either. It's just good, or good enough. The bass quality is a step or two below the Empire Ears dynamic driver IEMs like the Odin and Legend X, but its quite competitive with name-your-chifi product of the month, and likely beats it when you consider that the bass driver is pushed to its limits here.

The soundstage isn't huge -- its fairly average for an IEM, which means its small, but acceptable. Imaging is just okay, and depth is alright. I wouldn't be looking at the Maestro Mini as a technical wizard, as it is not. It plays much better as a fun, fun IEM that actually sounds quite pleasant and enjoyable.

Final Words​

So, if you are a big bass lover, but also want something that can actually work across genres well, this is a pretty good IEM, and its priced decently well for a possibly niche area where there isn't a lot of stuff that excels in pure bass quality.

The MEST series has been one of my favorite IEM lines since Unique Melody first came out with the original bone conductor-featuring quadbrid earphone. The original MEST had used two "new" IEM technologies at the time with a bone conducting driver and electrostatic tweeters to go along with a dynamic driver and a series of balanced armature drivers. This review will take a look at the company's newest MEST branded product, the MEST MK3.

The original MK3 prototype and design that was shown around featured a ceramic shell with a plain looking design that had some mixed opinions. After running into supply-chain issues with the ceramic material for the shells, and collecting feedback, the UM team decided to use a more familiar and popular look from their limited run Indigo product and released the MEST MK3 in a similar blue and a new red colorway. The one I was sent for review from Unique Melody is of the blue variety.

With a shiny gold rim, and translucent blue faceplate and shell that displays little pieces of carbon fiber within it, the MEST MK3 is really a nice looking IEM. It has a very comfortable medium-to-large shell size that fits me perfectly. I was able to wear this for hours at work without problems. The shell is made from a lightweight plastic, which also helps with the long-term comfort.

The custom cable that comes with the MK3 comes from PW Audio, and is designed to match the looks of the shell design. The connectors are come painted in a popping blue color and are very well-built. The Y-splitter, and chin strap are also matching in color and metal material. The cable is 2-core, but with each core shielded and thick. The lower portion of the cable is rather stiff, as it isn't woven, and instead has both of the L/R cables running in parallel with each other, and wrapped with a fabric braided sheathing in dark blue. While its a very nice looking cable, I do find the extra stiffness and weight to be a little annoying to use in practice. It is not too bad if you are stationary, but if you're moving around, the cable can be a frustrating experience.




In addition to the cable, the MEST MK3 also comes with a beautiful and well-designed leather case. This case is a round 2-piece design with a smaller lower cylinder where the products go into, and an upper, larger top that closes down on it. It's one of my most favorite included cases with an IEM that I've seen yet, and I even like it more than the very cool Dignis zipper case that came with the MEST MK2 and MK1 prior.

One of the newer products from Unique Melody that is also included with this IEM and the previously reviewed U-FREE truely wireless IEM is their umbrella-shaped tips. This pairing, however, is quite bad with the MEST MK3, and one I would not recommend -- at least in my experience. I'll discuss why in my sound impressions section, but I did end up finding great fit and sound with my typical sets of SpinFit tips that I use with most of my IEM reviews.

As with prior MEST products, their packaging contents are very good and if not top notch. I only wish they pick a more softer cable, and its the same nitpick I've had through all their products. But everything else is great, and I can't deny that the cable looks fantastic and well-built.

Sound Impressions​

MEST MK3 takes a similar approach to tuning as prior MEST IEMs. It stays on the warmer and slightly darker side of neutral, and comes across as a warm-bodied, and very pleasantly tuned in-ear. It has a slightly elevated bass range, steady mids, and a darker treble range that is well-extended on both ends of the spectrum. I find it a very solid darker U-Shape tuning, and should be very familiar to those who have listened to prior MESTs.



While general tonal balance is similar, though not exactly the same, the approach on the rest of the tuning does differ. There is definite MEST DNA in the MK3 - with a similar driver configuration, and overall design, but the MK3 refines the overall sound significantly, over both the MK2 and MK1. This is, by far, more coherent than the other two, and comes across very smooth and lacking a sense of disjointed bass that the other two presented to me -- whether that was for good and for bad.

Now that said, that lack of full cohesion, did give the original MEST its charm. It's bass felt isolated and singular, away from the rest of the mid-range and treble, and the upper-midrange had a very unique holographic sound to it, that also sounded weird, and different and made it so original-sounding at the time. The MK2 cleaned it up a bit, and maybe to its dismay, made the MEST MK2 sound a bit ordinary, albeit still very good.

The MK3 doesn't necessarily have these issues, or benefits, depending on your preferences. It still retains the holographic soundstage that all of the UM Bone Conducting products exhibit, but it brings everything together more coherently, and packaged better. It does not sound ordinary like the MK2 does, and it doesn't sound crazy like the MK1 did -- it's somewhere in between with a nice sweet spot of just sounding good.




The resolution on the MK3 is excellent. At first, I tried using the included UM tips, which are very soft and reminiscent of the Azla Xelastec tips, except these have scalloped edges that make it look like an umbrella. With these tips, the resolution is very apparent, but it also killed all depth, soundstage, and imaging from the product. I actually was shocked at how untechnical the MEST MK3 sounded at first, because the included tips were the first set I tried the MEST on. They fit great and everything, but the sound was like someone shouting into my ears.

With different tips, and literally any other tip, the sound presentation opened up and the stage widened and deepened, and it felt much more natural and more like something I was expecting for a $2000 IEM. The soundstage is still smaller and more intimate than my CIEM MEST MK1 and the universal MEST MK2 I compared the MK3 against, but it was fine, and the differences in stage were very little.

The resolution was much the same. The other MEST excelled at bringing out the micro-details from recordings, and I did not feel the MK3 gave up any of this at all. It only made them less sharp and more natural.

Yes, the MK3 is probably the most musical of the three that I have and compared against. It doesn't go for the most precision edges, nor the biggest bass bloom, but it just has a nicely tight knit and warm sound that is very easy to enjoy and get lost in the music with, and it does not suffer from the occasional blips where the upper-mids and treble can be a bit bright and harsh that the others experience. It's very sweet and gentle in its treble presentation in this regard.




Listening to different music genres with the MEST MK3 gave me some insight into which I prefer most with the MK3. This isn't a neutral IEM that is indifferent to musical choices. It's pretty close though. For my liking, I really enjoyed the MK3 out of music with brighter notes, and shriller highs. It went well with classical and jazz music, where a variety of instruments are at play, and it tames the horns and strings well, without losing the quality of the sound -- in fact making them sound sometimes more warm and natural.

In rock music, I did find the darker tonality to be beneficial for some music and perhaps suffocating some other songs. For tracks with an excessive amount of electric guitars buzzing like metal, this combination really does well. For others, like alternative rock music, it provided a good grunt of meat, but at times closes in the song a bit more than I like, which for a genre that already suffers from the bad period of lack of dynamic range, makes it a bit more dark and missing some sparkle.

I loved how the MEST MK3 sounded on acoustic rock songs though. My endless plays of various progressive bluegrass and alt-country songs sounded well with this IEM. The fiddles, banjos and violins sound well controlled, with the added acoustic bass guitars and drums feeling heavy with good rumble.

Final Thoughts​

My recommendation for the MEST MK3 is to try different tips. This one can sound pretty different with what tips are thrown on them, as I had already discovered, but almost forgot about, with the original MEST MK1 and MK2 units. Once you find the one you like, I think the MK3 really shines and comes off as a very engaging and smooth listen, with good technical performance and a very warm and rich sound that is well-extended at the same time. It doesn't do a lot wrong, and is a great cohesive affair, and something that brings a new life to the MEST line.

The DO300 is a new Digital-to-Analog Converter (DAC) from SMSL and it features the latest ESS flagship DAC chipset, the ES9039MSPRO. The unit comes in at a retail price at $549 and is available to order from our friends at Aoshida Audio. (https://aoshida-audio.com/products/smsl-do300)

The product was provided by Aoshida for this review. As per usual, the review is my own set of impressions, and my link is unaffiliated.

I have recently reviewed the whole fleet of the SMSL DO and HO series DACs and headphone amplifiers, starting with the small and solid 100 series, and the middle 200 series. The 300 series, here, does not currently have a matching headphone amplifier, and I was told there are no current plans for a release of a HO300. That said, the HO200 should stack perfectly with the DO300. I still use the DO/HO100 series daily at work, as it has plenty of power and its compact size makes it a nice desktop compliment to my laptop and monitor for work use.

External​

The DO300 has a similar look to the DO200. In fact, visually, its almost indistinguishable if it wasn't labeled with their model numbers. They both feature a small color screen on the right side, a multi-functional knob down the center, and the same set of input/output ports on the back, in the same exact locations.

This includes XLR and RCA outputs, and a variety of different inputs: AES, I2S, Coaxial, Optical/Toslink, and USB-A. In addition, there is a bluetooth antenna which has the latest Qualcomm Bluetooth 5.0 standard, and allows for LDAC, AptX-HD, AptX, AAC and SBC formats.

Under the hood, there are a few new upgrades. The biggest change is the aforementioned DAC chip. This SMSL unit is built upon the ES9039MSPRO DAC chipset, the newest flagship from ESS. In addition, the unit employs 11 op-amps for output to the RCA/XLR ports and eventually to your amplifier.

This unit also features MQA decoding support, and will light up blue or green when activated.

Firmware Features​

The color display can be controlled by the multi-functional volume knob, or with the included remote. I prefer navigating this with the remote, as it makes it quite a bit easier to use, as there are quite a bit of different options to play with.

The menu is the same as the DO200 MKII that I reviewed. Users can navigate through menus to change inputs, outputs, variable or fixed volume mode (preamp), jitter control (DPLL), dimmer, brightness, and most importantly to me -- PCM and DSD filters, and the SMSL's audio Sound Color menus.

The digital filters include 8 ESS Sabre filters to choose from:

• Filter Off
• Minimum Phase
• Apodizing
• Linear Fast
• Linear Slow
• Minimum Phase Fast
• Minimum Phase Slow
• Low Dispersion

The unique one that I don't remember seeing before is Filter Off. I didn't know you can disable over-sampling on a Delta-Sigma DAC, so this was an interesting one to see and to play with.

For the Sound Color menu, there's an addition series of filters:

• Standard (off)
• 3 Levels of Rich
• 3 Levels of Tube
• 3 Levels of Crystal

Each of these, I presume, plays around with EQ and phase to provide a different type of sound that was subtle, but distinguishable sometimes.

Sound Impressions​

For this review, I primarily listened with my Hifiman Susvara headphone through the Bakoon AMP-13R amplifier. My normal day-to-day DAC in this set-up is the Holo Audio Spring 3 KTE (with pre-amp module), which is an R-2R resistor ladder DAC as opposed to the Delta-Sigma chipset-based DO300 DAC I am reviewing here.

My high-level takeaway here is that I actually really enjoy using the DO300 DAC quite a bit. It presents an alternate listening experience to my more analog sounding Spring 3 KTE, and for being a more precise listen, the DO300, has a very smooth overall sound.

In many ways, going to a relatively lower budget DAC with a D/S chipset implementation can have a brighter and more sharper type of sound. This, of course, isn't always the case. I really enjoyed Audiolab's use of the old ES9018 DAC in their A6000, and found that they smoothed out all the glare issues normally found one of those older Sabre DACs.

With the DO300, there's a lot of play here that you can customize how you want the DAC to sound, with its selection of 8 filters and 10 coloring options. I found using Filter Off (No Oversampling) to be my favorite but I was perfectly happy with the traditional Linear Fast and Linear Slow filters too. For coloring options, one of the Rich or Tube, or default Off was quite enjoyable. The Crystal options made it sound, as you would expect, a little more bright and gives a sense of more detail, but at the expense of being a bit fatiguing.

The DO300 is very resolving, and clear, but does not have what I consider a sense of faux-clarity, where excessive treble/brightness makes details more forward and sharp. Instead, I found a sweet treble that I thought mixed well with the overall sound.

The DO300 is punchy, and layered. It's punchier than my Spring 3 KTE, which is a little more warm and soothing versus ultra-neutral. Characteristically, I find the differences are most apparent when you listen to how strings resonate, and even their base frequency note sounds different between the two. The Spring sounds natural, but slightly dampened in a way, but resonates more organically, while the DO300 has a more defined and incisive strike, with a resonance that also has this brighter hue to it that isn't quite digitized, but isn't also a warm, soothing fireplace feel either. It's a bit hard to fully describe these general differences between the R-2R and D/S sounds in just words, without listening to it.

Wrap-Up​

SMSL's DO300 is a very nice DAC that makes use of the latest from ESS with their ES9039MS PRO DAC chipset. This little unit has a variety of sound tuning options within its simple and colorful display that is easy and intuitive to control with the included remote.

I was happy with the overall reference sound, with good resolution, punchy bass, and sweet and smooth treble. For a well-measuring, reference-type DAC, this one checks a lot of boxes for me in a small desktop-sized box.

The Supernova is a flagship in-ear monitor product from Indonesian boutique maker, 7th Acoustics. This product comes in at a small $750 USD price tag for a flagship, and has a total of 6-BA drivers in a nicely laid out package. The unit was sent to me by another review, Theo of Precogvision and Headphones.com fame, as part of a 7th Acoustics tour.

I had just published a review of the Proxima the other day, which is a neutral reference budget IEM from 7th Acoustics. This one is their top of the line model and takes the neutral tuning and adds a small bass shelf that puts it into my preferred territory, and matches it up directly with my beloved Hidition Viento "B" CIEM.

The Supernova comes in a taller round tin container than the Proxima, with a screw-on top. While this is secure and a nice touch, the metal screwing on metal can be grating at times, but not a big deal.

The Supernova comes with a very high-quality CEMA cable that I absolutely adore. It is a copper-colored braided cable with large 4.4mm pentaconn connectors on the source side, and 2-pin connectors on the IEM side. The 4.4mm connector has a striped gold and chrome/silver look that I really enjoy and matches the similarly styled Y-splitter.

7th Acoustics went with a very traditional universal IEM fit with a rounded triangular shape and a medium length nozzle. It's an easy fit for me and is very comfortable. The front faceplate has their logo above an abalone design. The one this unit came with is a blue/green look, but there are many other color options available on the company's Facebook page.

Sound Impressions​

As stated earlier, the Supernova adopts a balanced and mild U-Shaped tuning that is very well aligned to my target preferences. This has a small bass shelf that downward slopes into the mids, and a gentle rise in the upper-treble and a very smooth and extended treble range. The Supernova has a neutral-relaxing signature with added low-end warmth.



The sound signature of the Supernova is easy to comment on. It's good. I enjoy the balance throughout the frequency response, and the smooth sound that comes with it. It does not have any disjointed transitions, and is very coherent in general. I don't have a lot of to complain about in the tonality choices made here.

On the technical side, I also have little to complain about, especially at its relatively low $750 price tag, which falls many times lower than other brand flagships. Its even lower-priced than my Hidition Viento, and is going to compare well with the Thieaudio Monarch MK2 and Clairvoyance.

The Supernova has pretty good resolution. It doesn't exert all the minute details that I sometimes hear on the Empire Odin or the Unique Melody MEST, but I also don't feel like notes are smeared, and transients are overly rounded. In fact, I actually am a little surprised at how sharp notes can sound sometimes, however, knowing that this is an all-BA set makes a bit of sense.

Sound separation and soundstage in general is medium to wide for in-ears. I never felt the intimate and sometimes very forward and small sound of the Proxima, and there's plenty of space between instruments that makes listening to big orchestral pieces here sound decently grand. The Supernova also does a good job of providing depth, but it's not the best I've heard.


Comparison to the Hidition Viento B




When I first looked at the FR curve for the 7th Acoustics Supernova, I immediately thought of the Hidition Viento-B, my daily-driver CIEM. And measurements-wise, they are quite similar as shown above here. But they do differ a bit in overall sound performance.

First off, I find the Viento to be surprisingly warmer, but also a tad brighter. The warmer part was a bit surprising, based on the graph, but it could also be due to the totally perfect fit of a custom-fit versus a universal-fit of the Supernova.

The Supernova has a more quick response with crisper edges and a little more definition to certain notes. That's not to say it is more resolving than the Viento, it just means that the Viento has a longer decay and sustain-ability, which does not sound as exacting. Which is more natural? That's tough to say. I think the Viento comes across a little more natural, but the Supernova comes across more clean and technical in this aspect, with also a slightly wider soundstage in my listening.

In some ways, the Supernova is a more up-to-date Viento-B, and that's a good thing in my viewpoint, as again, the Viento is my ideal IEM, though sometimes seeing its age in the technical ability versus newer flagships. Both are also strong in coherency, and that is perhaps where I find the Viento a little better, but it really is a toss-up. Some people may not like the smooth sound of both of these, but I'd ask, why not?

I've had the pleasure of an extended review loaner of the $3499+ ZMF Caldera that's been at times on my head and off-times off my head over the course of several months now. It is no fault of the Caldera at all, it just happened to be a rather busy period of holidays, being stricken with illness, recovering, traveling, and just a busy work schedule. But, every time I do reach out for the Caldera, it's been a nice, pleasurable listen that I am going to discuss more in this full review.

First off, I did provide my first few days of listening impressions way back in November prior to the headphone's launch. I was lucky to have been able to get my hands on the headphone to try out from Zach of ZMF himself, and have been holding on to it for quite some time, though sharing it with several members of the Seattle audio community in the months I've had this in my possession.

Each local audiophile auditioner loved what they heard, and I can go more on that later, as I did collect some notes to discuss.

The Headphone​

The ZMF Caldera is Zach's first foray into a custom-designed planar-magnetic driver. Previously, he started the ZMF company on the backs of modifications and improvements to the Fostex T50RP series of planar magnetic headphones. He introduced new internal mods, and his famous and unique wood-cup designs to the headphone and went through a few different iterations, before switching over to custom biodynamic driver-based headphones, and then the beryllium-based drivers of the Verite series.

The Caldera brings him full-circle back to his roots from 2011, when he made his first modded T50RP. The new design here is an 80mm planar driver that has an impedance of 60 ohms and headphone sensitivity of 95 dB/mW. It's not a hard to drive headphone, but it may push your portable gears to the other end of its volume limits than the beginning.

The unit that was sent to me is the standard Oak wood cups with black grills, rods, and chassis. This is the basic model, but as with all ZMF headphones, there are upgraded color and metal options, and limited edition wood runs that are very popular and always look stunning. As I am writing this now, there is a limited run of Bocote and Redheart woods available.



Each Caldera order comes with 2 sets of pads of your choice, and a cable with the termination of your choice. Every order is customized for you, and because each wood piece is unique, you'll get a surprise of how it looks when you open the box. Each one I've seen, in real-life or online, have been spectacular looking, and owning ZMF headphones previously, I've never been disappointed in quality of the build, or appearances of the wood pieces. The Caldera is no different.

The new headband design is more padded than ever and is designed in a way that makes the weight of the headphones feel much lighter than the scale will tell you. For most headphones over 450 grams, I typically feel the weight of them pretty quickly. This one scales at well over 500 grams, but it still feels comfortable for long listening sessions.

The pad options included in this set were the Caldera leather pads and the Suede pads, as well as a cowhide pad that was a bit thinner than the other two. The Caldera leather and suedes were on the thicker side, but are both very comfortable to wear. Each of these have their own unique sound characteristics that I will describe in the sound section later.

The cable included is the new ZMF standard headphone, which is a black-cloth sheathed copper cable comes terminated in the connector of your choice, and meets the headphones with the standard mini-XLR jacks that are normal on every ZMF headphone.

Sources​

I primarily used the 1/4 inch cable with my listening sessions, although there was a balanced XLR cable available in this kit. I did try using that for quite a bit of time early on with my iBasso DX240 DAP, but for the most part, I used the standard unbalanced 1/4 inch cable with my Bakoon AMP-13R and Holo Spring 3 KTE set-up I use for headphones.

Sound Impressions​

Some of the following will be a bit of a re-hash of my prior impressions, but I'll try to add more detail and some sample impressions as I write this, along with some feedback from community members who have also had an opportunity to demo this specific set over the past few months.

The Caldera is a warm-tilted, and slightly-dark sounding headphone, but doesn't stray too far away from what I consider a neutral sound target, at least for a typical ZMF. It's easily the most traditional reference sounding headphone that I've tried in ZMF's lineup, but it also continues to feature a heavy dosage of the ZMF House Sound that has a warm and rich mid-range that is quite engaging and enjoyable, and a sweet treble range that is extended and smooth. The bass extends into the sub-bass fairly well, and is generally linear throughout with a little dip as you go further down to the sub-regions.

If someone took the tonal balance of an Audeze planar (e.g. LCD-4) and a Hifiman planar (e.g. Susvara), and split it down the middle, I'd say you'd land pretty close to what the ZMF Caldera sounds like. It takes the best parts of both, and gives a very well-balanced headphone in its tonality.



I enjoyed using the Caldera a lot with rock music. It's the stuff I grew up on and I always love listening to 90s alternative and this headphone does it quite well, and better than my "end-game" Hifiman Susvara. When I listen to Alice in Chains or Smashing Pumpkins, or even Radiohead or The Ataris, there's just more meat on the bones on a Caldera than a leaner, but more elegant Susvara. The Caldera has more body in the mids and a slightly darker treble range that eases off on the wailing guitars and crashing drums, and gives more thickness to vocals, bass guitars, and kick drums, that help give more raw power to these anthem tracks.

When I put on some Nickel Creek, and their brand of bluegrass music, I still found the Caldera to be quite enjoyable, with a good soundstage, imaging and instrument separation. The band's trio of string instruments sound defined, but don't necessarily have the crispness that they would sound on the Susvara, and trails just behind it on resolution for these very minute details such as the faint strings fading away in the background. But, the Caldera still does a commendable job on resolution and soundstage -- it's just not as open and resolving as the Hifiman flagship that also cost over 50% more.

In terms of planar magnetic headphones, the Caldera is one of the closest to a dynamic driver sound that I have heard. It's still "fast", but the weight of the notes, and the richness in its presentation, along with the longer decay give it a more natural sound than the typical Hifiman planar headphone that have stocked my collection through the years.

Pads​

The pad material options do play a role and a fairly significant one here.



The standard leather Caldera pads have the most neutral sound of the three I had, and provides the most dynamics and punch. The transient speed felt the fastest here, and most intricate.

The suede Caldera pads offered a smoother sound, with a little less emphasis in the upper-midrange and low treble, and more rounded edges and slowing down the overall transient speed.

The cowhide pads are quite a bit thinner than the other two in size, and with this, made a very different sound presentation. I found this one darker in the upper-mids with a treble lift that is similar to the Verite series. I thought this still kept the snappiness of the leather pads, but also gave a more holographic soundstage, but with a much more wonky tonal balance that I liked the least.

More Listening Impressions​

I took these out to a couple audio meets in the Seattle-area over the winter months, post-pandemic, and had a few people I met in the community try them out. For the most part, I think everyone enjoyed what they heard, with some seriously contemplating buying them. Some compared these to the Atrium, another ZMF headphone with a similar tonal balance, but in a dynamic driver configuration.

The Atrium is one of my favorite headphones, and I absolutely loved using them for rock music when I had them on loan from ZMF when they first came out. They were my favorite ZMF at the time, and now the Caldera has surpassed them for me, because the Caldera improves the resolution and its tonality fits my preferences more.



But that said, there were folks who preferred the dynamic driver sound on the Atrium over the planar sound on the Caldera. The Atrium is a little bit richer with a stronger note presentation and longer decay. It's ever slightly darker, and so there were people who preferred this thicker and more relaxing presentation over the Caldera.

There was another listener who really loved the Caldera and has been contemplating buying one for a while now, as an upgrade to the Hifiman HE-6. When this person first listened to it, he thought it was good with the Caldera leather pads, and was already thrilled with it. Then we swapped out the pads with the Suede pads and I quickly observed his smile grow as he listened to them. It seemed like a serious "A-Ha!" moment had occurred! At the time of writing this, he was still deciding whether to buy this headphone or not, but hopefully he'll get to demo this set again in a couple weeks and go from there.

Like I said, of the dozen or so people who tried it, I didn't see or hear any dislikes or even "so-sos". Everyone seemed to enjoy the Caldera. Some still preferred the sound of a dynamic headphone and leaned toward the Atrium or Verite, but all of them really enjoyed that ZMF sound, despite other top end headphones around.

For me, I don't necessarily care one way other the other if it's a dynamic or if its a planar. There's some characteristics that help kind of define the sound of the two, but I find that that is changing as we evolve headphone technology anyway. The Caldera has a lot of carry-over sound that reminds me of a ZMF dynamic headphone, more-so than most other planars. It is a great in-between, and does so with a good all-arounder sound.

Final Thoughts​

The Caldera is a great headphone. It has the ZMF DNA in it -- wonderful wood aesthetics, solid build quality, top notch customer service, and the typical warm and lush, engaging mid-range I've come to expect from their products. For folks that had hesitation on ZMF's tonality in the past, this one, along with the previous release, Atrium, should help provide a different outlook -- it sure did for me, despite being owners of other ZMF gears in the past.

Several months ago, I did a Dongle Discourse Shoot-Out and I crowned the Cayin RU-6 my champion at the time. While, I still consider it my favorite dongle of that batch, I wanted to re-visit some of these dongles a bit more, and today I will take a deeper look at the iFi Go Bar, a very popular and pricey $349 USB-C portable DAC/Amp that is full of features, and my opinion of it has changed a bit since then.

The iFi Go Bar I am reviewing is actually from Headphones.com and was sent to me from Precogvision of their team many months ago, but I still have it here for now.

Accessories​

For this premium dongle, iFi included a very nice leather case that can carry both the unit and the USB cable(s). The unit comes with both a USB-C to USB-C cable, as well as a USB-C to Lightning cable, along with a USB-C to USB-A adapter. This should fit most use cases for digital transports, whether that be a computer, laptop, tablets, an Android phone or an iPhone.

Buttons & Features​

The iFi Go Bar has a couple features that are controlled with 3 side buttons. First off, you can control volume with the two volume controls, and the third button switches between X-Space, X-Bass+, both of them on, or both of them off. The default is off.

Holding the third button, and then using the volume controls will toggle through the various filters iFi has put into the Go Bar. This is a nice feature that was lacking on some of the other iFi products, and required firmware rolling to change digital filters, if that was even an option.

I also prefer this option because I haven't been a fan of iFi's preferred Gibbs Transient Optimized Digital Filter, aka the GTO Filter. The GTO filter reduces the taps in total, making it a short filter, and minimizes the pre and post-ringing, while also being asymmetrical. Typically, most DACs default to a symmetric filter with both pre- and post-ringing with a steep cut-off. What is best is sort of up to the user to decide.

While the features are abundant for a small little dongle DAC, I am not a big fan of how to determine what settings you are on. Over time, you can memorize or just remember what things once you get the hang of it, but the tiny LED dots, and the tiny text is already likely hard to read, but then you add in the fact that they chose a light grayish-blue (periwinkle?) text color on top of a dark gunmetal gray shell design, makes it exponentially harder to read, no matter how much light, what angle its coming from, or how much you squint. It's barely legible, if at all for me, as someone who doesn't require eyeglasses for anything.




In addition to the main buttons, there is also a toggle switch that enables the iFi IEMatch, which attenuates the sound and adds a small impedance gain to the circuit to help reduce noise from the amp. I am going to go on a quick soapbox here, because iFi could, you know, just make their default circuitry less noisy, but they choose not to. At least in this case, they added IEMatch to the setup, instead of making you buy their rather overpriced standalone attenuators. But, if you use output impedance-sensitive IEMs, typically ones with multi-BA setups and high sensitivity, you may run into problems with the tonality of your IEM changing with the extra impedance added. For many IEMs, it could be nothing or minimal, but some products from Vision Ears or Campfire can be rather drastic changes in either bass, treble, or both.

Sound Impressions​

For sound, I primarily used this product attached to my laptop and used Roon as the software source, playing both local files and music streamed from Qobuz and Tidal via Roon. For IEMs, I used a variety of different products like the Empire Ears Odin, Hidition Viento, Xenns Mangird Top, UM Mest, and the 7th Acoustics Supernova, among others. I also used it with the Sennheiser HD600 headphones. For all cases, I stuck to 4.4mm balanced for output.

Quickly going back to the IEMatch and amp noise. Yes, the Go Bar can be noisy. There was audible hiss on many of my IEMs when I had audio active, and in quieter parts of music or general playback. It was a bit annoying, but this wasn't a problem with the Sennheiser HD600. I tried to stray away from using IEMatch because some of my IEMs may be sensitive to changes in impedance.

Using the iFi GTO filter (white LED), I found the sound rather bright and a bit digitized when listening to Mipso's self-titled release. Switching filters while playing music was rather simple, and quick, and surprisingly, I felt going to any of the other filters provided gave a more warm and enjoyable listen - whether that be the standard linear filter, the minimum phase filter, or the "bit-perfect" filter (no digital filtering).

I stuck with the linear filter, as that's the most standard for the rest of my listening along with the HD600 headphone, since using IEMs gave an audible hissing noise.

For the most part, the Go Bar doesn't do anything wrong. It's quite neutral sounding to my ears, with no real emphasis in any part of the spectrum, unless you enable one of the digital processing effects. XBass+ gives a big boost to the bass region, with what I believe is a +10dB down-sloping curve through the bass region.

The XSpace plays with phase and cross-feed to give a more 3D-ish holographic sound, but does make the overall sound much more lean and seemingly strange. Adding both effects enabled provides a better tonal balance and gives a slightly larger soundstage, and is what I'd recommend using for brighter headphones.

With that said, I preferred sticking it out without the effects on. And with that I found the iFi Go Bar to provide a clean, and resolving playback presentation, and perhaps the best iFi portable presentation I heard yet -- all from memory of course. While soundstage wasn't large and more intimate without XSpace enabled, I didn't find it glaring or too forward that it became a claustrophobic mess. Technically, it handles busy passages and simple ones quite well, and outside of the noise issues and preference of filters, I don't have any negatives to say about its sound.

Wrap-Up​

The Go Bar is every bit iFi in my opinion. It packs a lot of features and is built pretty well. Unfortunately, as many iFi portable products have, it makes a lot of amp noise that is audible in higher sensitive products like many IEMs, which can be a killer. Luckily, this product does include the attenuating IEMatch feature, although it can also change the frequency response of some IEMs when enabled.

With that in mind, it does work well, and has enough features that sets it apart from the crowded dongle space, but it is also the most expensive that I am aware of on the market, making it a bit hard to recommend overall.

*note: the volume knob has been replaced with a larger gold-colored knob as shown in this photo


The Piety is a custom run of a previously prototype design of a Magni by Schiit that was taken by longtime audio community member CeeTee and produced by hand on a small-scale with his own branding, Nitsch. This Piety borrows some of its Continuity circuit amplifier topology from Schiit's Jotunheim 2, but in a much smaller form factor.

One of the reasons Schiit never took this specific design to market was due to a shortage on some of the parts, as they were no longer being produced. That allowed CeeTee to do a limited run with the scarce parts available and make this somewhat of a rare collector's item headphone amplifier.

The Piety shares the same chassis and exterior looks of the Magni series that Schiit is probably most famous for. It blends the black and silver options of the sibling product into a Gunmetal gray finish that makes the Piety stand out a little bit more unique than the Schiit line. There is also a square Nitsch logo on the top corner of the amp.

The Piety does not offer quite as much power as the other Magni amplifiers, but it does supply adequate power for the majority of headphones on the market, with only some challenges with the most difficult to drive planar headphones in my experience. I had no issues with headphones like the Sennheiser HD600 series, or any IEM I threw at it, and it worked well with the ZMF Caldera. It struggled a little bit more with my Hifiman HE400SE and Susvara.

With IEMs, there was surprisingly no noise floor issues at all. I've had hit or miss experiences with Schiit products on this front, and the Jotunheim 2, for example, had some audible noise with some of my IEMs. The Asgard 3 did not however, and neither does the Piety.

Speaking of the Asgard 3, I would think that this was the most similar characteristics of the Schiit amps I've tried/owned and remember hearing. I did not have any Schiit amps to compare to directly, but I had owned the Asgard 3 for quite a while and really enjoyed it for its warm and pleasant sound, and the fact it had a very, very low noise floor. The Jotunheim 2 was a bit brighter but very punchy, and despite sharing the same topography, I did not find these two similar at all, from reviewing my notes.

Sound Impressions​

The Piety is marketed as a Triode-like sound. For those unfamiliar with what this may mean, its representative of a tube-amp sound, while still being a solid-state. For the most part, I can see why the marketing print states this, and early listening impressions provided such statements.

With every IEM and headphone I threw at it, and with my primary listening coming off of the Empire Ears Odin and Hidition Viento IEMs, I found the Piety to be quite a bit darker, warmer, "slower", and rounder than my other gear. This type of description can be what you may hear on what a typical tube amp could sound like, however not all tube amps I've heard are necessarily dark. Some can be bright too, however, but that's for another day.

The Piety, when compared to a typical op-amp based solid-state, sounds quite unique. I spent some time comparing it to the SMSL C200 DAC/Amp, as well as my iBasso P5 Falcon portable amplifier, which I've modified with a custom configuration of op-amps (TI OPA1622, MUSES 02, and a pair of Burson V5i discrete op-amps).

The C200 gave the most precise and probably most in your face sound of the three. The customized P5 had a nice gentle and smooth treble with a wide soundstage, but felt open and grand, while still having quick transients and precision sound. The Piety was quite noticeably darker with slower progressions. It had a soundstage in-between the two, and a much thicker sound.

The Piety works as advertised I'd say. It gives users a different sound that is unlike others that I have found in this price range, with a darker, thicker, and more lush sound. It lacks on power, but should work well with most headphones. I found the crazy warm-warm pairing of an R-2R DAC and the Piety to work quite well surprisingly, but its definitely something I think users would enjoy with neutral and brighter headphones, and it may be just too warm-bodied for already darker headphones.

The Hifiman Susvara was once quite ridiculed and hated for its outrageous price tag at its time at $6000. Yes, that's right, it's $6K. And it still is today, 6+ years later. And while it's still one of the most expensive headphones on the market, there are others in this price range now that compete with it, including even more expensive in-ear monitors!

Some of the vitriol against this was the entertaining video interview between Tyll Hertens and Fang Bian, the owner of Hifiman, and also Hifiman's long-going quality issues and relatively lack-luster build quality for their asking price. It's true, the company focuses primarily on its driver technology and its stellar tuning, and sometimes slaps it together in whatever form-factor that'll work.

After always dreaming about this headphone, I decided to just sell off the majority of my headphones and audio collection except a few essentials and just buy up this unit. I've always wanted to get my hands on this unit, being a long-time fan of Hifiman's tuning and lightweight designs, despite fragile they can be sometimes.

So, it was to my surprise that the Susvara's build is actually not that bad. It shares similar designs with my previous two Hifiman staples: the HE560 and the Arya, and can actually be considered a smashing of the two. It's not quite round, and it's not tear-dropped either. It's kind of an oblong-circular cup design with the same style headband as my two prior headphones. The headband removes the plastic yokes and has full-metal headband and yoke design that feels very strong and sturdy. The grills are aluminum and don't have any issues with creaking or feel like they're going to implode on themselves.

There is still the goofy wood veneer from the HE560 though. It's not the best, but it is not appalling either. I'll take it.

The Susvara nano-scale diaphragm and magnet structure were its major selling point, allowing it to have major improvements in resolution and clarity, as well as what I'd say better tactility and impact. One thing that was interesting when this headphone came out was that the majority of Hifiman's releases were moving more and more towards efficiency and allowing their planars to be played on a variety of sources. The Susvara goes backwards a bit in this movement, and has power requirements more akin to their old HE6 model, with a rated sensitivty of 83dB/mW and 60 ohm impedance.

This means, you'll need an amp with at least 2 Watts into 60 ohms to really get the best out of the Susvara, and for the most part, I think this is quite true. I've run this on a gambit of sources and the ones with the most power seem to really show off the most characteristic features of the Susvara the best, with my current pick being a 50 Watt (into 8 Ohm) integrated speaker amplifier using the speaker taps as my headphone connection.

Before I go further into the sound qualities, I do want to mention that the Susvara's unboxing experience was kind of lackluster for the $6000 MSRP tag. It came in a latched box, which was alright, but did not include a portable travel case, and the cables are horrendous. They're the same ones that come with the HE6SE V2, HE1000SE and a few other recent headphones.

Hifiman did include a hardcover photo book detailing the features and process of designing the headphone, which is a pretty nice coffee table item.

So apparently, I started writing this review in May 2021, and I stopped my writing at this point in time. It was so long ago, I forgot I had even wrote anything. I tend to be slower or sometimes never get to reviewing products I own, but anyway.... Since, it seemed like nothing really changed, I will continue writing the review from where I left off, nearly 2 years later in March 2023 now...

Sound Impressions​

The Susvara is my favorite headphone. I've owned it for over 2 years now, and I've tried many other headphones before and after that point, and it's still the one I go back to. The Susvara has a very neutral reference sound that doesn't color anything. It's not as bright as your typical Hifiman, as it doesn't have any random peaks in the treble range, and it doesn't have a large dip in the mids as some planars do. The bass levels are flat from the lowest sub-bass regions through the mids, and begins to rise just after 1KHz, and extends well into the upper treble range, giving this a nice clean sound that doesn't exaggerate any one frequency range in my opinion.




Before I dive further into this, some may have read my adventures in amping the Hifiman HE6SE V2, and going deep down the headphones and speaker amp rabbit hole with it. I ended up with a Bakoon AMP-13R after all was said and done, which is a 25 watt (into 8 ohms) speaker/headphone amp that was designed from the ground up around the Susvara, and it shows. It's a perfect pairing, with a warm-bodied sound compliments the neutral sound of the headphone.

So, yes, the Susvara requires some power to get going. It will drain your digital audio players, and will require you to push them to their limits to get it up to listenable volumes. When I tried it on a Chord Mojo, for example, I drained the entire battery of it in 25 minutes. My iBasso DX240 audio player can get it loud, but bass performance was severely lacking. And, basically, don't even try it out of an Apple dongle.

Using the Susvara dropped me deeper into the DAC rabbit hole too. I settled in with the Holo Spring 3 KTE at some point, and now my chain starts with Roon, through the Holo Spring 3 KTE DAC, and finally into the Bakoon AMP-13R, where spits audio into my ears via the Susvara. And for the most part, it is ultra bliss.





The Susvara is source dependent. I mentioned this with the HE6SE V2, and the same can really be said with this one. If you put a bright setup with it, it'll be bright. If you put a warm source behind it, it'll be warmer. But in all cases, it's still fairly neutral in its overall tonal presentation.

This headphone really excels at resolution. It's a detail monster, and it presents it in a very open and large soundstage that is layered with texture and micro-details when called upon. The bass presentation is nuanced and fast, and is unlike many other headphones I've tried. It doesn't necessarily have the long, lingering decay of a good dynamic driver, but it can slam with the best of them -- if you give it the current it needs to give you the volume and drive it takes.

On the morning that I'm writing this out, I'm jamming to Nickel Creek's latest record, Celebrants. It's a progressive bluegrass record that truly excels on Susvara. Acoustic music is one of the specialties that I feel Hifiman made shine on their creation. The intricacies of each instrument are on full display, with a large and grand soundstage, and quick, exacting detail projected to each of my ears. The sheer speed and agility of the string-play the band presents can be fully appreciated on the Susvara, because its driver can keep up and then some.





I've had Hifiman headphones from their entry level up to this flagship in the past, and when I compare say the entry level HE400SE or the HE6SE V2 to the Susvara, I can quickly discern the differences in sheer speed of the driver. The faster transients that I hear make a big difference in how resolving the headphones sound, and while I adore and use the HE400SE quite often (it's my work-office headphone), I can easily hear the resolving deficiencies between this entry level headphone and the Hifiman flagship.






I put on a more upbeat, but, still acoustic album, Mipso's self-titled record from 2020, and listening to songs like the faster-paced "Hourglass" sound wonderful on Susvara. The bassline hits well, and the snare drum is timely and not distracting. It falls behind the scene as it should, and let the vocals shine. The lead guitar and bass guitar intro of "Your Body" sound very coherent and balanced, while Libby Rodenbough's sometimes breathy and strained-sounding vocals are so full of detail, that you can hear the transitions between the loud and quiet singing quite well and without skipping a beat.





Now, I will say, some may find the Susvara a tad bright, or perhaps too neutral. And there is some truth to that. It's definitely not very colored, and may not have as much warm body as other headphones that people tend to compare this too, such as a typical Audeze planar, or a ZMF headphone -- both of which have warmer mids, darker treble, and a fuller-bodied sound. These are their house sounds, and Hifiman has always strayed towards a less colored, and sometimes bright-tilting tonal balance.






For alternative rock and hip hop music, I still find the Susvara enjoyable, but perhaps this isn't its strongest suit. For me, these genres could use the extra mid-bass or mid-range body, or perhaps a little darker skew to the treble range that tames some of the electric guitars or electronic treble-inducing beats. And in that case, I prefer listening with the fantastic ZMF Caldera, another planar open-back headphone with a more warm and fuller tuning.

Even so, putting on Radiohead's The Bends is still a treat. It's can be a tad bright at times with the amount of electric guitar and high hats going on in the busiest parts, but that depth and layering qualities the Susvara can present is really something -- and a band like Radiohead, who is all about those intricate details in every one of their songs -- its not a bad thing at all. "Everything in its Right Place", for example, sounds incredibly large, awe-inducing, and hypnotizing on this headphone.

Final Thoughts​

I could probably write more and more about this headphone, but at some point I do need to stop. While I don't think its probably the be-all-end-all headphone for everyone, it is for me and my musical preferences. I love this headphone for jazz, for bluegrass, for acoustic music. I enjoy it for electronic and classical, and rock. I don't know if I'd like it for hip hop, modern pop, and soul music as much, but I have other gear for that.

Obviously, this is an EXPENSIVE headphone, and it more than likely requires an EXPENSIVE set of sources (DAC and amp), which adds more to the cost, and so "easily recommending it" is not something I am going to do. But, this headphone does give me so much enjoyment listening to it that I find its value proposition still kind of ridiculous at times, but perhaps I justify to myself that it is an investment in quality and quantity -- and by quantity, I mean years of service. This is a for-life headphone, and not likely one that will be replaced. It's been on the market for 8 years now, and still popular and still being purchased today.

With that said, and a random note, my other "most-used" headphone is nearing its 27 or 28th year now -- the Sennheiser HD600. I haven't had it for that long, of course, but it is something to say that the two headphones I use the most are not just flavors of the month, and they've, so far, tested the passage of time with flying colors.

When the original Yume came out from SeeAudio, I was very excited to see an in-ear that nearly matched my "Antdroid Target Curve." Of course, I did do a little bit of modification to it since then, but it still closely aligns to it, with the major difference being a little lack of upper-treble extension. But FR alignment wasn't everything, as I found the Yume to have an overall mushy and rounded-transients presentation that made it sound a little sluggish and below average in technical performance for its price point, and ended up giving it a mostly average to above-average score.

Not too long later, SeeAudio came back with an updated model with the backing of famous reviewer Crinacle and his tuning consultation. The Yume Midnight had improved in extension, with a little bit of a warmer and thicker sound, and overall improved tonality, but still lacked the technical chops to make it stand out in its price range. It still presented top notch tonal balance, but its limited technical capabilities made it only a slight improvement over the original.

Now, a year or so later, the Yume 2 is in my hands thanks to a review sample provided by Linsoul. This 2nd generation model features a single dynamic driver, and 2 balanced armature drivers and retails for $199 at Linsoul.com (https://www.linsoul.com/products/seeaudio-yume-ii).

Unboxing Experience​

The Yume box is a navy blue of sorts and a Yume female mascot graces the top of the box. Inside, you'll be greeted with a white SeeAudio jewelry box which houses the Yume 2 in-ears and the really nice and beautiful white braided cable. Inside the box, there are also a variety of tips and accessories.

The jewel box presentation is pretty clean. It is simple, yet elegant and the box is soft and padded and comfortable to carry. The inside has a little button tie-down to hold the cable down to, and is lined with a padded felt material which protects the aluminum housings on the Yume 2.

The cable is extremely lightweight, wonderfully simple and modern-looking, and does not tangle and maneuvers easily. There is a little bit of retained spring-memory, but I did not find it bothersome in my usage. The connectors terminate in 2-pin to the IEM, and 3.5mm to your music source.

The Yume 2 shells are aluminum metal with a polished mirror look. There is a inscribed yellow flower design at the center of each front faceplate. It is an attractive look that I think many will enjoy. The shells are also very small, light, and fit wonderfully. No pain or concerns for my ears.

Sound Impressions​

The Yume 2 is a very well-balanced IEM with U-Shaped tonal balance -- slightly warm bass and mids, and an even and relaxed upper-midrange and treble, with extension in the upper range.



The frequency response between the Yume series is quite similar across the board. The original Yume has the least mid-to-upper bass, with a more sub-bass focus, while also have the least treble extension. The Yume Midnight and Yume 2 have practically the same bass and mid-range, but differ slightly in the upper-mids, with the Yume 2 have a little more upper treble. Overall, the Yume 2 takes the best parts of both predecessors and increases the treble range making this the most well-rounded of the series.



Tonality aside, I found the Yume 2 to have improved technical response than its predecessors. When I compare it to the competing Moondrop single dynamic driver IEM products, I find that the Yume 2 to have faster transients, and wider soundstage. It also sounds a little leaner and less intiamate than say the Moondrop Kato or the Aria.

The Yume 2 still has a very forward sound, and has a few flaws pop out when the volume is increased. The bass response is quick and agile, but does not have a lot slow decay that makes it sound natural either. It decays a little too fast for my liking.

Due to its forward sound staging, I feel like it lacks depth and separation can be a little dense at times, but for the most part, it works. It's an intimate listen, and that's alright for most things.

Final Remarks​

The Yume 2 is a solid refresh for the series. It improves the tonality by taking the best of the series and adding more treble extension. The design is fresh and clean, and is very easy to wear and to look at when not in your ears. Its limited only by its bass performance being a little lacking and it being a little more on the intimate side of staging, but still an improvement in technical performance over previous generations.

This is a solid buy when comparing it to its price range competition and SeeAudio taking on Moondrop at their own tuning game and besting them perhaps for the same price point.

The DO200 MK II is the successor and a new DAC from SMSL which features dual ESS ES9068AS DAC chipsets and retails for $469 on Aoshida Audio's website. I personally never had an opportunity to try out the original DO200 DAC, so this is a new experience for me, but I am quite familiar with SMSL DACs and headphone amps from owning and reviewing many, many of them in the past.

This review unit was provided by Aoshida Audio and you can find the DAC here:
https://aoshida-audio.com/products/smsl-do200-mkii-mqa-audio-dac

This DAC is medium-sized -- still small enough to put on a desk, but it wouldn't look too tiny on a shelf either. It's roughly the size or slightly smaller than that of the Topping A90/D90, or the Schiit Asgard/Bifrost/Jotunheim. Despite the small footprint, this DAC has a lot of input/output options for users to choose from.



The rear of the unit has both balanced XLR and single-ended RCA outputs to feed an external amplifier or speakers. The central input section has options for USB, Toslink Optical, Digital Coax, and the less common AES and I2S input connections. There is also a screw-on bluetooth antenna attachment included that provides a wireless connection from your bluetooth devices.

There is a main power switch on the back that cuts power completely, and pressing in the function button on the front of the unit turns on and off the unit from standby. The multi-function knob also controls volume and scrolls through the various menu options. There is also a remote control for easier use included.

One of the new visual items this unit has that I have not seen on other SMSL products is a new menu interface on the display. It's a much more colorful, and easier to see display. It's easier to use as well and lets you control a lot of options from the input/output selections, the digital filters, and other unit options.

General Sound Impressions​

The SMSL DO200 MK II is a very detail-rich DAC that sounds more exacting than rich and warm. Its not overly analytical like some DACs that may have this description and I don't find it overly bright on my choice of amps.

For my listening, I mainly used the Bakoon AMP-13R with it, which I find as a warmer than neutral source. I also used it briefly fed to the iBasso P5 portable amplifier when used with IEMs. For headphones, I mixed between the Hifiman Susvara, the ZMF Caldera, and the Sennheiser HD600 for listening.

One sound that I enjoyed a lot was Mipso's Hey, Coyote. This is a very gentle, acoustic song with an airy nature to it and both male and female backing vocals in a progressive bluegrass folk sound. The notes come off very crisp and clean. The plucks on the combination of fiddle, mandolin, and guitar are very gentle and defined at the same time. I enjoy this definition and exactness in a song like this where each acoustic instrument can express their own character clearly and free from embellishment.

DACs are a pretty hard thing to discern differences from in my cases, and it becomes a little harder when you are comparing chipset to chipset based DACs. My main DAC, however, is an R-2R-based DAC which uses resistors ladders and produces a unique sound that is different.

When I compare the SMSL DO200 MK II to the Holo Spring 3, I found that the Spring 3 had a bit more of an engaging and rounded sound, that was slightly warmer, and deeper in its texture capability. The Spring 3 had a more natural resonance to it, while the DO200 MK II sounded crisper, cleaner, and in some ways, flatter, in this not very apples to apples comparison in many regards (chipset, price, etc.).

I also compared the DO200 MK II to the other SMSL DAC I received, the DO100, which is quite a bit smaller, and half the cost. In this case, the DO200 MK II sounded just slightly more refined, though the differences were not night and day at all.

In many ways, they sounded quite similar, and in this regard, the differences in price and size is more geared towards having more plentiful options for input choices, and an easier to navigate and colorful menu system that looks better than just a simple white OLED screen.

The S12 is LetShuoer's new and first planar in-ear monitor and comes in at $149 USD. This IEM packs a large 14.8mm planar magnetic driver encased in a all-metal shell and comes with a fancy multi-colored braided cable and a tin case. It's quite a decent package all together and it has a nice resolving and clean sound that should please many.

First off, I'd like to thank Joseph from LetShuoer for reaching out and sending me a review unit of this new product. As some may know from reading my past reviews, I'm not always the biggest fan of Shuoer's previous products, in fact many of them rank in quite the lowest tiers of my ranking list, but the recent EJ07M and this product is starting to change my opinion of this brand with a new name.

So let's just get down to business.​

The S12 is a really nice sounding planar. A couple months ago, I reviewed the Timeless planar IEM from 7Hz, and gave the $219 IEM a rave review with some of the best commentary feedback I could give at the price point. Driver-wise, these two are similar in size but the S12 goes a step larger and increases the driver from 14.2mm to 14.8mm. Now, I don't know if these are similar drivers at all, or made in the same factory, but the driver plus tuning combination between the two IEMs are quite similar and very enjoyable.




Unfortunately during this review period of the S12, I did not have the Timeless on hand. I had lent it out to another reviewer, ufospl2 of Headphones-N-Stuff, for an extended listen on holiday, and so he's out there, somewhere, enjoying that set. Instead, I'll just have to manage this written review without that crucial A-B comparison, at least in the near term.




The S12 presents a small bass-boosted take on a balanced/neutral sound, that is right up my alley on tuning preferences. The mid-range is just slightly recessed with forward upper-mids and a generally smooth treble for me, however, some could find a slightly excess energy peak in the treble range, depending on how deep of a fit you can manage. There is also a nicely extended treble which helps with percussions and strings.

Many of the same characteristics I wrote about in the Timeless review can probably be brought over to here, but one of the key differences (from memory of course) is that I find the S12 just a little smoother, a little warmer, and with an extra amount of sub-bass rumble. These are things that I do not really think I mentioned in my Timeless review, but I can write here.



I never found the S12 to have the occasional bright glare on random tracks either, and I played this through a gauntlet of acoustical tracks from country to bluegrass to folksy music to female pop songs. The S12 handled them all quite well and with a good amount of "fun" for my tastes.

The tonal balance of the S12 is really solid in my opinion, however it doesn't have the fastest planar-like transient speeds. It's not quite the same speed and precision as my Hifiman Susvara, and is more along the lines of the Hifiman HE400SE, which is actually a very similarly priced $149 headphone. That is, while there is a decent amount of quality and resolution for this price tag, I don't think the precision is there. There isn't that extra layer of detail or exacting edge to each note that makes a higher tier driver or IEM stand out. It's not necessarily blunted, or blobby, either. It's just good, but not great or exceptional.

In addition, I find the S12 to have a relatively small and condensed sound. It's not grand and majestic, but provides a more intimate soundstage and more up and center presentation. While I don't mind this and it's never claustrophobic, I do like a wide and open soundstage personally, and this does not quite hit that mark.

But, all and all, I find these little things to be rather small in negative points when you take a look at what you're getting for $149. This is a very nicely put together package of build quality, accessories, and great tuning and above average sound. LetShuoer did a very nice job here, and they hit it home with great values in the last two IEMs I've tried. Things are changing for the better with this brand!

The Mangird Tea came out a while back with some positive reviews and a decently pleasant overall sound. I personally enjoyed using it for its warm and somewhat too polite sound. It lacked a bit of air and treble, but the overall mid-range and bass was on point. Fast forward to now, and Mangird has rebranded to XENNS, but still also carries the Mangird name. Confusing, I know. But the Tea 2 is their new product with XENNS packaging, and Mangird on the faceplate. Luckily, its a good sounding IEM and let's dive a bit more into it!

First - Linsoul did provide me this review unit. It retails for $349 and can be found here: https://www.linsoul.com/products/xenns-mangird-tea2

Unboxing​

The Tea 2 comes with a silver-colored braided cable with 2-pin connectors which is pretty nice to use and easy to handle. It's soft, and doesnt tangle easily, which is a bonus.

The faux-leather jewelry box is clean and attractive, and it has plenty of space for the IEM, with cables attached, a little mesh pocket for tips or small accessories.

The Tea 2, itself, is a comfortable-fitting, acrylic-resin IEM with a barely-translucent black finish, and a very subtle, yet attractive faceplate with varying shades of blue reflective flakes across it. The branding, "Mangird" is written in cursive across the faceplate, though it's not tacky in anyway.

Sound Impressions​

The Tea 2 takes a lot of the same sound signature of the original Tea, but adds more quantity in the upper midrange and lower treble region to give this Tea 2 set a much more balanced sound, whereas I found the original Tea to be tasteful, but a little dark and muted. The general sound is very appealing to my ears, and falls closely along what my preference target curve is.






The bass levels on the Tea 2 are quiet nice. I like that it is warm-tilted, but not muddy, and focuses more on sub-bass. That said, the bass quality isn't the best at this price range, and does come off across as rounded, and missing an extra layer or two of depth. For example, when I listen to Bill Laurance Trio's live version of the Pines, the stand-up bass guitar is just one-noted, and missing details. In "Signal in the Noise" by GoGo Penguin, the kick drum intro is more of a thud sound that something with expression. The overall quantity is really quite nice, however, and in most listening, I do value tonal balance over quality.

The mid-range extending up to the upper-mids is vastly improved over the Tea in my opinion. There is now no veil and not a dark sensation I got with the original Tea. The quantity here is perfectly fine and ideal. Perhaps there could be a bit more in the lower treble region to increase the dynamics and air to the overall sound, but that may lose the general "Tea" sound of being a warm, and comfy, cushy sound.

In general, I find the Tea 2 to exhibit a really solid balance of bass, mids and treble. Perhaps, a little more treble would improve its sound a tad, but there's not a lot to really complain about here. The technical performance is average for its going price of $350, but it is still a solid contender and improved quite a bit over the original Tea. All of that said, given its price, it'll find stiff competition from more technically gifted and similar tonality in the Moondrop Blessing 2 series, the 7Hz Timeless, and the S12 from LetShuoer.

The TTROMSO is a new IEM by Tipsy that is named, incorrectly, after the Norwegian town of Tromsø. The theme around the IEM is based on the Aurora Borealis, I'm presuming, with its color pattern and design. The IEM retails for $89, and is a single dynamic driver in-ear with a V-shaped sound.

The TTROMSO was provided for review by Linsoul, and can be found on their retail store at Linsoul.com. The unit comes in a single color choice of PineStone Sea blue/green, and has a matching blue-colored IEM cable with fabric sheathing. It does get tangled fairly easily, but is otherwise extremely lightweight and comfortable.

The shell has a sea-green and blue look, with something of a borealis or ocean/algae look. I can't really tell for sure. That said, this is an extremely easy to wear IEM that is very lightweight and small, and should fit comfortably with most ears.

Sound Impressions​

The TTROMSO is a V-shaped sound, with a big un-neutered bass boost and a equally big gain in the upper-midrange and low treble. It actually quite resembles my budget favorite CRA from CCA, which came out recently at only $14 USD. Imagine the TTROMSO as it's wiser sibling with a slightly more refined technical performance, but with all the same boombastic sound and occasional tingly sharpness.





TTROMSO's bass is dirty, and it's not clean, and it is really not that detailed, but it has punch and slam. The dynamics are decent, and probably on-par with the CCA CRA, and that's a good thing for a low price. Now, of course, this model is 6X more in cost, but still relatively inexpensive in the grand scheme of things. There's a big leap in overall bass quality when you move up in the 2x price range for sure.

The mid-range is mostly dominated by the upper-mids here, and on some tracks, I do find it a bit blaring and glaring, with a sharp and tiring attack. While the CRA had those moments occasionally, I do find the TTROMS to be a bit more fatiguing here.

That said, the overall mids and treble quality is a step up from the CRA, with slightly better detail, slightly better separation, and a little bit better exactness.

This IEM doesn't really blow its competition out and really kind of fits in-line with the rest of the under $100 price range. It's fun, and fits nicely, but I may consider spending my money on the CRA for a fun bass-heavy IEM and then using the rest of the money on a Moondrop Aria, and getting two solid IEMs with different styles for different music for around the same price as the TTROMS.

The RAPTGO Hook-X is an interesting new hybrid IEM that mixes two less common driver technologies together along with an even rarer open-back shell to create an exciting and somewhat refreshing new product on the market. The Hook-X retails for $239 and is sold by online retailer Linsoul. The product page can be found here: https://www.linsoul.com/products/raptgo-hook-x

As you suspect, this product was provided free of charge from Linsoul for review. And with that, let's talk more about this new in-ear monitor that's gaining some momentum in the community.

The Hook-X is a semi-open back design that has several perforations on the faceplate allowing sound to travel in and out. This isn't nearly as open as the Audeze iSine Planar series of IEMs, nor is it even close to an open-back headphone. It also still isolates more than ear buds, but it does let some sound go through and that's something I personally have been wanting a while just for my personal awareness around me, and the ability to relieve any pressure build-up and heat.

Inside this unique shell houses a 14.2mm planar magnetic driver and a "custom 18-layer double-side piezoelectric driver." With that said, I don't believe this is the same type of PZT ceramic driver that is found on previous IEMs which, in every case I've tried, have been piercingly bright and obnoxious to use. Nope, this is a different beast. In fact, the product box says its a bone conductor driver.

Bone conductor, you say? Like the Unique Melody MEST series? Like Aftershokz? Perhaps. It is also a known fact that bone conductor drivers are piezoelectric as well. So, I think that may end this confusion. And how does it sound? Well, that's the interesting part, and I'll talk about that after I discuss some cables and accessories.




Yes, as per usual, this product comes with a bunch of tips, and a fake-leather gray zip-up case. It's actually a decent case with a pocket inside and plenty of space to store things.

The cable included is green, just like the accents of the shell, and the cable connectors and also share green accent rings as well. The green braided cloth sheathing has a glowing green look to it, and it does look pretty neat. In actual use, it can become a tangled mess at times, but not too bad and not too annoying.

The connectors at the shell are flush-mounting 2-pins, and the opposite source end is a swappable cable feature. Included are a set of standard 3.5mm, and balanced 4.4mm and 2.5mm modular connectors. This specific modular connector-type is similar to the ones found on a lot of the newer chi-fi products coming out, such as from Kinera, Tripowin, and TRN. I am not 100% sure they are interchangable, but they all feature a push/pull insertion method with 4 pin connectors, and aren't held by a mechanical locking mechanism. Either way, it extends the length of the source connection by about 1/3rd of an inch and is not too distracting.

Sound Impressions​

So about that bone conduction thingy: My first impression putting these on and playing a variety of indie rock music was essentially, "wow, this is different." I couldn't totally put into words exactly what I was hearing. It sounded tonally balanced, and nothing really bad to say overall about its frequency response, which later measured just as well. But, there was just something unique about how it sounded in the mid-range, which coincidentally reminded me quite a bit of listening to your normal, average bone conducting earphone, such as the ones made by Aftershokz.

I happened to have a set with me just two weeks back, and had quite a bit of time listening to one of them, so I did have that interesting playback and presentation of music recently pushed into my mind. Literally? It's a different sound if you have never heard it before. It plays music, but it comes across more soft, more grainy in a way, and is not anything I would call high-definition, high resolution audiophile sound.



The Hook-X's initial impression has that type of mid-range to me. In my first pass through with, again, a lot of indie rock, vocal-led guitar music. I put down the IEM and wrote down my impressions online, as a record.

My first impressions of the Hook is that it actually has a mid-range that reminds me of the softness and lower-resness of Aftershokz, which I have listened to recently within the last couple weeks. That said, its a pleasant sound, maybe too smoothed over, and missing exacting detail and edge. It's tonality is for the most part fine, it just presents sound a little softer and different. I wouldn't call this hi-res audio for some reason, but this is just my initial impressions after about an hour of listening. These are very comfortable to wear and the color of the cable is really nice. Connectors are also swappable.

Click to expand...

After coming back and listening several times with this IEM throughout the past week, my impressions went from medicore, to not bad, to somewhat enjoyable, to "wow, I just listened to these for 4 hours straight and it's way too late in the evening!"

What changed? Nothing really. Well, I did get a new DAP in-between listening sessions and going from the Hiby R5 Saber to the iBasso DX240 is a pretty big jump in quality. But, I did quite a bit of listening on the Chord Mojo/Poly as well, so I can't say it's just do to the step-up in source quality.

I think the Hook-X can take a little bit of getting used to to really enjoy its presentation style and uniqueness that is a little different than the other two recent planar IEMs on the market making a splash right now. In those, I mean the 7Hz Timeless and the LetShuoer S12, which I both enjoy and recommended in the past.



The Hook-X has a much more analog, cozy, and comforting sound to it that is different than the faster, edgier, and more in your face, high-definition-like sound of the other two planars. It does not necessarily put out the best hi-res quality, but it's still an enjoyable listen and beats other IEMs in a few areas, which made me spend hours and hours at night listening to this IEM.

What it does bring is a somewhat natural, analog, and somewhat lively sound that has good imaging and a good sense of space and openness. This could be partially attributed to the open-back nature of the shell, but the frequency response may also play a bit into this with a less forward upper-mid-range than other IEMs. I was surprised that I was able to overlook the grainy nature of the mid-range, which is pretty important to me, and just chill-out and relax to hours of various rock and jazz music and even listening to some old skool R&B jams.

The treble is extended and while it doesn't have the most air of IEMs, it still has plenty of output in these extreme areas to provide proper sounding percussions and reed instruments, all while not sounding muted and congested.

Final Thoughts​

The HOOK-X puts together an interesting package. It cost just a tad more than its competition, but is one of the rare semi-open in-ears on the market. It has an interesting sound signature that originally I disliked, and as I listened more, you can say that it "hooked" me in.

If you're looking for something that is clear, crisp, and forward, with the sound and presentation that is fast and hi-definition, this isn't the one you're looking for. If you want a more low-key, cozy and an analog-feeling sound that is easy on the ears and willing to sacrifice clean and clear mid-range, this isn't a bad choice at all. Normally these "analog" type sounds turn out to be horribly tuned (outside of say the Vision Ears and Sony gears), but this one is did a surprisingly good job of drawing me in over time and making me enjoy it as a nice alternative to my normal listening pattern.

The Pegasus is an R-2R Ladder Digital-to-Analog Converter (DAC) made by Chinese brand Musician. They are a new brand, which some have lumped with Denafrips, but Musician has their own expanding lineup of DACs, amplifiers, and streamers now. The Pegasus was their first product and one I purchased recently at their retail price of $1099 USD.

The Musician Pegasus uses a resistive ladder design instead of typical DAC chips that are found in many popular DACs out there that are normally using ICs from ESS, AKM, Cirrus-Logic, or Texas Instruments/Burr-Brown. This much more complex design requires matching many, many resistors and soldering each onto an intricate circuit board to create the conversion. Many of these DACs can be quite expensive, with some of the flagship products costing well over $10 to $20,000 USD.

In the case of the Pegasus, it is on the lower end of the R-2R market place as it stands today, though many may see that its still priced higher than many traditional DACs from Topping, SMSL, or the rest. The Pegasus does not cheap out on design choices or input/output.

The machined aluminum chassis is very well built and feels very premium with a unique 3-legged foot design and interesting bevels. The back of the unit has a variety of inputs and outputs. It'll output both single-ended RCA and balanced XLR, while taking in USB, Toslink Optical, Digital Coax, and the HDMI-based I2S. In both USB and I2S formats, the Musician Pegasus can take in sample rates of up to 1.536KHz, which is a whopping 32X sample rate, or two to four times more than most DACs on the market. It'll also transcode DSD format as well.





The high sample rate plus the "Non over-sampling", or "NOS", button makes a nice combination for users like me who rely on the third party up-sampling software, HQ Player, to do a lot of the DAC up-sampling, filtering and noise-shaping dirty work. In this case, I was able to up-sample to 32X without a hitch using Sinc-L filter, and I found the results quite pleasant.

On the hardware side, I really wished that Musician had included a remote control feature, and that all inputs were active when on. Each input is disabled when you change to a new input, and without the remote feature, it does require getting up and manually pressing the input button on the front of the device. Not a huge deal for some, but those who use this in a living room set-up or away from your seat of choice, it can be cumbersome if you use a variety of sources.

Sound Impressions​

At the time of purchase, I had been primarily using the Chord Qutest DAC in my main headphones listening station paired with the Bakoon AMP-13R headphone amplifier, and Hifiman Susvara headphones. I also have a Wyrd 4 Sound USB Recovery regenerator in-between the Roon Server PC and the DAC. I also use a variety of other gear such as the Sennheiser HD600 and HD800S, but the majority of my listening time comes with the Susvara.

I haven't had an R-2R DAC sitting in my home before, and the few times I've heard them were at meet-ups. I have owned the Schiit Bifrost 2 previously, which is also a multi-bit DAC, but uses a chip-based implementation and not an R-2R Ladder. I had heard about R-2R's warmer and more natural tuning, so I had some expectations coming in.

Surprisingly, I found the Pegasus to have a very neutral sound signature that had a slightly above neutral low end warmth and a sweet and smooth treble, though slightly rolled-off in NOS mode (without HQ Player) and less so on standard over-sampling mode. This was mostly in comparison with the Qutest, which I found to be very neutral, incisive, but not analytical.

If I were to really dig into the weeds, I'd say that the Qutest takes transients with a slightly edgier attack, while the Pegasus is more rounded, with a smoother finish. The Qutest excites with detail because of this, while the Pegasus still has all the detail but transitions gentler.

Without HQ Player, I did find the Qutest had a bit more depth, maybe an extra layer of detail. When I added HQ Player to my chain and upsampled to 1.536KHz to a NOS-enabled Pegasus, it really shined. The HQ Player's up-sampling, filtering, and noise shaping scheme added a noticeable rise in resolution, depth, and a slightly added mass to many of my tracks that really gave the Pegasus an even more natural and refined sound.

In my combination of headphones, amplifier, HQ Player/Roon settings, and DAC inputs, I decided to keep the Musician Pegasus in my system. It gave a different, but more natural and softer sound to my Susvara than the Qutest and I actually ended up appreciating that over the faster and edgier sound of the Qutest.

This review was a copied over from: https://www.audiodiscourse.com/2021/11/musician-pegasus-r2r-dac-impressions.html