Audio-Opus Opus#1

I give Nik (AKA nmatheis) many thanks for lending me his own personal unit for this review. This device opened my eyes and changed my thinking on a number of things, and for that, he has my deepest gratitude.

I spent a little over a week with the Opus #1, by theBit (or Audio-Opus, depending on what you read). This was not a DAP I pursued. I didn’t join any tours, for there were none to join. The opportunity merely came along, and I thought, “Hell, why not?” What serendipity, that what amounted to a text-based shrug, would land in my lap one of the best players I’ve ever heard.

But I’m getting ahead of myself. Let me talk about the build first.



It’s solidly made. That’s the extent of my praise. It’s sturdy. It won’t fall apart on you. The buttons work. The screen works. Everything works. But it’s so boring! Where’s the artistry? Where’s the flare? Look at the Cayin i5. It’s so pretty! I want to touch it when the lights go out. That’s the sort of reaction I want from a DAP: carnal desire! I guess I have a DAP that does this for me. It’s called the AK120II. Astell&Kern spoiled me with the level of luxury they offer. Of course, they charge you a premium for it. But Cayin doesn’t. The N5, and now the i5, are stunning, and reasonably priced.

theBit could learn a lot from them.

In my portable music players, I’m more than a little obsessed with volume wheels. They delight me something fierce. I flat out won’t buy another DAP without one. And it seems I won’t ever have to. They’re all moving in that direction now. Or at least a good many of them are. The Opus #1 doesn’t have a volume wheel. Ok. I’m a big boy. I can deal for a week. But that’s not its biggest sin. It’s that the buttons aren’t easy to use. They’re small, and if you have the case on, there are no cut-outs, just impressions stamped into the material. This makes for some clumsy use of the hardware interface.

It’s not an indomitable burden. Nothing like on the scale of the FiiO X5 Classic’s scroll wheel. No, the Opus #1’s hardware just reminds you in small, subtle ways that it’s not as fancy or as nice as other players. That’s a d@mn shame, because it doesn’t sound anything less than a top of the line product.



There isn’t an over-abundance of features to cover. Which is good for Pinky’s stats, since I’m not going to cover even half of the features the Opus does possess. Still, a few items caught my attention.

There are two slots for external microSD cards, in addition to 32GB of internal storage. That came as a great surprise, and I immediately gave it extra points for being so thoughtful. It’s amazing how rare that is these days. It has Balanced output, which, at the very least, I found convenient, since so many of my cables are terminated for 2.5mm TRRS. The Opus #1 sports one of the best Deep Sleep modes. When I first opened the package, the device turned On instantly. It had been On during transit, and yet it was close to a full charge. Sleep Mode is so efficient I never felt the need to turn the DAP Off, and the battery did not drain to any noticeable degree.

As great as Sleep Mode is, you will drain the Opus #1 through hard use. When you do, I am happy to say, it charges very fast. But only when powered up. I don’t think it charges at all when shut off. Even from the USB port on your PC, it takes just a few hours to reach Full. My AK120II takes many more hours to charge, when not using a wall-socket adapter.

The software UI is simplistic yet feature-rich. Finding the settings menu took a few frustrating minutes, however, but I eventually figured it out. You swipe down. Of course you swipe down. But you must swipe fast, because if you hold your finger at the top for even a full second, swiping down only brings up the time and date. That is useless. That information is also present in the full drop-down screen. So making it its own screen only confuses what should be an easy procedure.



Alright. I don’t want to talk any more about features. It’s a fairly bare-bones Android Device, after all. This thing doesn’t care about anything but audio performance. And that just so happens to be what I want to talk most about.

Since I complain so much about DAPs trying to be Smartphones, I feel I ought to give theBit kudos. The Opus #1 does not suffer from a development whose focus and resources were divided and ultimately squandered on idiocy. There is no Bluetooth. No WiFi. No Apps Store. All their money and energy went into sound quality. And OH GOD does it show!

Upon first hearing the Opus #1 by theBit, Pinky’s dwindling follicles were not blown back in awe. It sounded digital and artificial to me, like many budget-fi and mid-fi products. Then I listened to another album, and another, and realized the Opus merely reveals exactly what is recorded, and does so with powerful fidelity. SEA CHANGE by Beck uses a lot of digital filters, and I could hear those filters in vivid detail. Moving on to The Rolling Stones, and you hear all the analogue distortions they use to create their iconic sounds. You listen to an artist who records clean and you get crystal clarity.

In truth, this device is 100% free of inherent harshness or digititis. It feeds your headphones only what is contained within the source file. It is quite neutral, but not the dry, or thin neutral you sometimes get. The Opus is fuller and livelier than, say, the FiiO X7. Yet just as detailed and revealing. The dynamics on display here are top shelf. There is better treble sparkle than I hear on the Astell&Kern AK120II, and maybe a little harder punch down below.

The AK120II is warmer, overall. There is lushness, found most notably in the vocals. It’s thicker, with more weight to the notes. On the Opus the vocals sound thin, but not in that bad way. They are so clear and vibrant that I don’t care if they lack some of that weight the AK produces. In the bass department, either one has ample power. They both sound rich and natural, and very detailed. Due to its brighter treble though, the Opus will seem more detailed.

The soundstage on the AK is wider. I couldn’t tell any difference at first, not until I played my 24bit masters of The Beatles. Those have a great sense of space, and as I switched between the AK and Opus, the difference is plain to hear. But on Led Zeppelin IV, I heard no change. Take this as evidence of just how good the soundstage is on the Opus. It’s properly expansive. Only in extreme scenarios does it fall a little behind.

Despite their enormous price difference, I can’t honestly say which is better. I listened critically, using an A/B switcher, and I feel my choice would come down to signature preference, or headphone pairing. In spite of how much it pains me to admit, there is nothing about the audio capability of my AK that bests theBit. The rendering of the Opus #1 is faultless.



My memories of the Cayin i5 are still fairly fresh in my mind. I had a rockin’ good time testing that DAP. I would put it close to the same level of the Opus. Except it doesn’t do balanced, and only takes one microSD card. That’s a big deal. Soundwise, the Opus is clearer, and will sound much more detailed. The i5 is a warmth monster. Huge bass, thick mids, and recessed treble. I’m given to understand, after burn-in, it mellows out and grows more neutral. But that didn’t happen during my review period, so I can’t say for sure. As a virtue of its signature, the i5 gives you a smoother, richer sound. It probably also has more driving power. By a little bit. The Opus is no slouch here. Not at all.

I won’t even go into how this thing compares against my backup unit, the FiiO X5 Classic. Except to say, I think I’m going to replace the X5 with the Opus #1 if I come across one at a good price on the Head-Fi Classifieds. I didn’t plan on writing that, but now that I have, I gotta say, I think that’s exactly what I want. It would be cool to have a backup DAP that I could take out instead of my AK, depending on how I’m feeling that day. I could never say that about the X5. Between the inferior sound and annoying UI, I never take it out beyond the occasional comparison for a review.

You shall find no bright-sounding headphones in my stables. Everything I own is a degree of warm and neutral-warm. Well, okay, I do have the Klipsch X7i, which is dead-flat. But everything else… Because the Opus #1 is so capable in the treble region, I feel a bright headphone may end up harsh and fatiguing. I strongly suggest pairing with a warmer transducer. None of the below qualify as “extremely sensitive”, but I do have “sensitive” IEMs. I discerned no hissing form any of them. They all had quiet backgrounds and sounded glorious. Apart from the neutral Klipsch, which sounded flat and boring, everything I tried on the Opus came alive as the best versions of themselves. I seriously couldn’t ask for a better pairing, with any of them.



The Rhapsodio Solar… ah, the Solar. My first, and only, CIEM. They have such pure, crystalline highs. I feared what the Opus would do to them, but I worried for naught. Solar is warm, and wonderfully bassy, and the highs twinkle just enough to add detail and keep them from falling to darkness. With the Opus, they are so very energetic. They are fed a staggering amount of information, allowing for superb imaging and separation. I hear more air from Solar than I’m used to. This paring is all about the masterful balance of extremes. Frightful detail and clarity. Mean-hitting, exaggerated bass. Thick and full mids. Sparkly highs. Opus is to Solar as spinach is to Popeye: Bigger and badder.



64Audio’s U12 with the ADEL B1 Module is Pinky’s notion of Heaven on Earth. It’s dark magic. There’s no reason something this warm and smooth should also present so spacious and airy. It’s impossible for recessed treble to also resonate and highlight a wide, organic world of a soundstage. Yet these do. The Ear Lens tech must play a large role in this. Whatever the case, and however skilled this sorcery is, these IEMs do need a rather neutral source. My AK is fine. But if you go much warmer, like with the Cayin i5, they do start to close in behind a veil of sorts. The Opus is the perfect pairing. Yes, it’s even more perfect than the neutral-warm AK120II. This extra touch of treble energy gives the U12 something it craves, infusing the stage with even more atmosphere and space. All the while, the bass is as strong, deep, and marvelous as ever it was. The U12’s vocals are lush and real. On the Opus, they are not as full and thick, yet startling in their transparency.

An old friend of mine, and the one who solidified my preference in signature, the Audio Technica IM03. I call them the poor man’s Solar. They are very, very close, not only in frequency response, but also quality. Those who’ve been around Head-Fi a while know how bitter a reality diminishing returns truly is. I don’t need to say much about this pairing. Just read the Solar section above. Everything I wrote there holds true here, only to a slightly lesser extent. Opus>IM03 is a fantastic combination.





I’ve all but replaced my Sennheiser Momentum 2.0 Over-Ears. Yet I just can’t do it. I can’t say goodbye to these. Not yet. Maybe after a year of little to no use I’ll create a For Sale thread. For now, I’ll keep them around and pull the bastards out to test DAPs and such. This decision is validated by the Opus #1. The Opus>Momentum is a marriage made in heaven. What an easy, reckless listen. Nothing refined or elegant about it, just raw passion and delicious tonality. One of my favorite things about the Sennheiser—and a big reason why I bought them—is the size of the soundstage. For a closed-back set of cans, it’s grand. The Opus maintains that staging. It drives the 2.0s with a full, vital sound. There’s no sense of being under-powered here. The bass feels good and the treble shines enough. The mids lack some clarity, but Opus helps matters as well as anything can. This paring can be enjoyed for hours upon hours without fatigue. There is nothing unpleasant about it.

So what portable full-size headphones did a scrotum-punch on the Momentums? Why, that would be the Meze 99 Classics, of course. Conventional wisdom says you shouldn’t look for an “upgrade” in the same price range as the thing you hope to replace. But the reviews on the Meze were so gosh-darn good I had to give them a try. “Better in every way,” is how I like to describe these when making a Sennheiser comparison. They are so clear! There is such a wealth of bass. Outstanding treble! Sparkly, sparkly, sparkly. But not sharp or nasty. Beautiful treble, which casts a numinous light over the otherwise warm presentation. The vocals are phenomenally clean. I mentioned earlier how the Opus renders the vocals with extreme clarity. Well, that is a trait of the 99 Classics, also. Together… words can’t describe it. They were made for each other. I don’t attribute tonality to a DAP or DAC. I feel that is the province of the monitor. The Meze 99 Classics possess one the richest, most natural timbres around, and the Opus #1 allows it to shine by not getting in the way, by helping in the areas it can help with, and not faltering on a single point. Together, the music is often breathtaking.



Knowing I dealt with a DAP which had relatively strong output, I made special effort to remember to test her on my Massdrop + Sennheiser HD6XX. At 300 Ohms and moderate efficiency, most of, if not all, the DAPs I’ve tested can drive them to a level I call “Too loud.” But very few mobile devices make them sound good. Or rather, full and complete. They always sound good. But not always complete. They were lovely off the Opus. The bass is marginally less punchy than from my desktop amp, the NFB-28, but it’s there, in maybe 92% of it’s glory. What about the mids and highs? Just fine. Nothing was out of place. The HD600-650 are not great for mobile use, but if you must, this DAP is more than adequate for the job.



Well that’s it, folks. That’s all I have to say about the Opus #1. The only thing I find less than orgasmic is the physical and aesthetic qualities. And even there, it’s nowhere near “bad”. It’s simply not exciting or sexy. But that sound… oh, that sound!

Before now, I've said I am not a fan of neutral. My experience with that signature could only be described as bright and harsh, or bland. The Opus has shown me proper neutral. The treble shines like a star above the deep, aggressive low-end, and pinned between the two, a gossamer sheet of brilliant, dramatic vocals.

What feels like just yesterday, I reviewed the Cayin i5. If the Opus had that chassis, particularly the gorgeous volume wheel, I don’t think I’d be able to stop myself from buying it this very second. The sound is that good. Only the mediocre build holds this thing back. Which may explain why I’m currently obsessed with getting my hands on the Opus #2, for audition and review. If that creep accomplishes what I expect of it, I will have my upgrade to the AK120II. The Opus #1 came fearfully close. That should make you pause.

-~::Pinky_Powers::~-

This is a review of the Opus #1 DAP.
 


 
The bit Opus #1 was sent to me by the bit for the purpose of this review. I’d like to take this opportunity to thank the bit and Kiwon for sending it to me.  
 
 
Last year I bought, and reviewed the bit Opus #11 DAC/amp and was so thoroughly impressed by it that when the bit asked me if I’d be interested in reviewing their Opus #1 as well I did not hesitate for a second before I said yes.
 
It’s available from both Amazon UK and Amazon US for £430 (tax included) /$399 (tax excluded):
 
https://www.amazon.co.uk/Resolution-Portable-Digital-Audio-Player/dp/B01B90MBEW/ref=sr_1_1?ie=UTF8&qid=1481030482&sr=8-1&keywords=the+bit+opus+1
 
https://www.amazon.com/OPUS-Portable-Mastering-Quality-Gunmetal/dp/B01B90MBEW/ref=sr_1_1?ie=UTF8&qid=1481030573&sr=8-1&keywords=the+bit+opus
 
For more information about the bit Opus #1 you can also visit the bit website:
 
http://www.thebit.co.kr/content/pubf.action?fn=product/product3
 
http://www.audio-opus.com/
 
I’m not in any way affiliated with the bit.
 
Short introduction to the bit:
The bit is a Korea based company founded in 2004.
 
This is what they say about themselves on their website:

1. Specialized in designing and development of ICT devices, including MP3, PMP, NAVI, Digital TV etc.
2. The staff of the Bit consists of highly specilized high-tech engineers, who possess a valuable knowledge and experience in developing set top box, etc. within Samsung Electronics
3. R&D family members formed a tight teamwork for the last 15 years that conduced to the successful mass production of MP3 players for the first time in the world.
4. Stable and reliable supplier of featured products for Samsung Electronics, Best Buy and SanDisc in United States.
5. PND consumer products export to Japan for 3 years, proving the highest quality of manufactured products.
6. Possession of the wide variety of technological solutions, including the ARM, WinCE, Linux, Android OS etc.

 
About me:
I’m a 44 year old music and sound lover that changed my focus from speakers to headphones and IEM’s about five years ago. At that time I realized that it wasn’t realistic for me to have all the different setups that I wanted and still house a family of four children and a wife so my interest turned first to full sized headphones and later also IEM’s.
 
My preferences are towards full sized open headphones and I believe that also says something about what kind of sound signature I prefer (large soundstage in all directions, balanced and organic sound).
 
My music preferences are pretty much all over the place (only excluding classical music, jazz and really heavy metal). My all-time favorite band is Depeche Mode although I also listen to a lot of grunge/indie, singer/songwriter/acoustical stuff as well as the typical top 40 music.
 
I tend to value function over form within reasonable limits.
 
I do not use EQ, ever.
 
I’m a sucker for value for money on most things in life Head-Fi related stuff is no exception.
 
Please note that all impressions in this review are my personal and subjective ones. What works for me may not work for you and vice versa. Also please remember that nothing is for everyone so it’s always wise to throw in an YMMV warning when sharing ones experience with audio gear so consider that done for this review as well.
 
Please also note that the five star rating is the concept chosen by Head-Fi for reviews published in here, one may like it or not but it’s what we (as reviewers) have as a tool to work with here. I rate products according to their price point i.e. a product that cost $100 and is rewarded with five stars from me is not necessarily as good as a product costing $500 and is rewarded with the same fives star rating. So does a product have to be perfect to receive a five star rating? In my opinion no, simply because there’s no gear that‘s perfect for everyone. For me to reward a product with a five star rating it has to be best, or at least one of the best, performing ones in its segment and at its price point. Others may have a different approach to this but this is how I feel and rate the products I review.
 
Built and accessories:
The bit Opus #1 is a DAP with touchscreen.  
 
The bit Opus #1 is available in two versions. The original with plastic housing and one recently released upgraded version with metal housing. I’ve got the original version with the plastic housing.
 
The maximum output power is rated to 330mW@ 16Ohm from the balanced output and 275mW@16Ohm from the single ended output. Output impedance is rated at 1Ohm (balanced) and 2Ohm (SE) respectively.
 
The Opus #1 has a sturdy plastic housing that feels durable but still it’s “just” plastic. Although the design is pretty basic I find the beveled edges to be a very nice touch both when it comes to looks and the feel when you’re holding the unit. The physical controls available are an on/off button on the top, up/down volume buttons on the left side and skip back/forward as well as a ply/pause button on the right side. The controls seems to be situated in a way that makes it very intuitive to use and easy to reach them. The Opus #1 does also have a touch screen so everything except from turning off the unit can also be done by using it (more about this later).
 
The screen in a 4 inch TFT touch screen with a 480 X 800 resolution. Coming from phones this resolution may sound very low but as a matter of fact the screen does what it does very well and serves its purpose more than good enough.
 
The Opus #1 offers one USB micro charging input which also doubles as digital audio input and data transfer when the unit is used as a USB DAC for your laptop/computer or connected in transferring mode. There’s also one 3.5mm single ended headphones output and one 2.5mm balanced headphones output. The SE output does also double as line out when that feature is activated but also as optical output. Last but, certainly not least, there’s also the micro SD card slot or rather slots as the Opus #1 offers not only the standard single slot but two of them. The #1 is rated to accept card up to 200 GB, this combined with a 32 GB internal memory makes total possible memory a full 432 GB, not bad for a portable device.
 

 

 

 

 
 
 
Functionality:
Like I’ve already mentioned the #1 does offer both physical and touch control. This is great in my opinion as the physical controls makes navigation a lot easier in certain situation such as when you’re out and about and especially when you’d like to control it without taking it out of your pocket. The placement of the physical controls seems to be pretty ideal for my usage and they’re always quite easy to find and only on a rare occasion have I pressed the wrong one even when I have the unit in my pocket while pushing the buttons. Of course when I’m at home or have the unit in front of me the touch screen is the superior way of navigating but I really love the fact that the bit included the physical buttons as well.
 
The battery life is fairly good and is said to be about 10 hours, without having brought out my stop clock I’d say that these numbers are fairly accurate from my experience. The power required by the headphones or IEM’s your using as well as the type of files you’re playing will of course also affect the battery life. Charging time is about 4 hours and although it’s quite long it have not really bothered me since I typically charge it when I sleep. The battery life in itself is not that impressive but the Opus #1 has one feature that makes all the difference in my experience: Deep sleep mode! Putting the Opus #1 into deep sleep mode makes battery discharge neglectable and it can be in this mode for days without losing much battery. Once you wake it up it starts working as normal in no time. This means that I very rarely turn the unit off properly but rather just use deep sleep and charge it when necessary, very convenient. 
 
The Opus #1 runs on Android but it’s an extremely basic version and there’s no internet or Bluetooth connection option available. This means that you will not be able to use any third party apps on it. On the good side the scaled down Android system makes the #1 very fast and responsive in every day usage. It’s also very easy and intuitive to use.
 
The touch screen is also very responsive and works equally well as any phone I’ve ever owned. By dragging down the top you’ll get a quick menu, just like on your phone if you’re using a fairly up to date Android version, that let you choose between a lot of features such as activating line out (through the 3.5 mm headphones output), putting the player in balanced mode, EQ (10 band paragraphic) etc. but also a shortcut to the players more advanced settings.
 
There’s also, of course, possible to use the touch screen to navigate in your music library and you can choose to browse your collection by artist, album etc. like on any music player app. If you choose this way of navigation the whole of your collection will show up independent on if it’s stored on SD cars 1, 2 or the internal memory. Personally I always use folder navigation and that also works perfectly fine. 
 
Overall my experience with navigating through the touch screen is very good with great response time and very stable operation.
 
The Opus #1 support all popular file formats for audio up to DSD128 and 32bit/384kHz files.
 

 

 

 

 

 
The accessories included are:
1 USB type A to micro cable
1 Screen protector
 
There’s also an excellent leather case available for the Opus # that cost about $50 and although it may seem a bit steep I’d strongly recommend getting one as I like it a lot. Not only does it fir like a glove and adds protection but I also find the case to make it more comfortable to hold the player.
 

 

 

 

 

 
The specs:
 
I’ve used the Opus #1 a lot for the last couple of months and my unit has played for well over 100 hours.
 
Demo list:
Sound impression:
The first thing that I noticed when I started to listen to the bit Opus #1 was how smooth and relaxed it sounded while still maintaining excellent resolution and transparency.
 
Bass extension and quality is excellent with no noticeable roll off in the lowest frequencies and very good quality through the whole bass spectrum. Mid- and upper-bass is equally great and doesn’t add anything that shouldn’t be there. My all-time favorite bass presentation from a portable source would be from the LH Labs Geek Out V2+ and I’m very happy to conclude that the bass presentation on the #1 is equally impressive in every way.
 
The laidback and relaxed sound continues in the mid-range that’s very smooth and liquid while still sounding totally natural and highly enjoyable. This combined with good timbre and great feeling of space between vocals and instrument makes a great sounding signature that continues in the upper frequencies.  The transparency combined with richness makes the midrange blend in great with the bass as well.
 
The treble presentation on the #1 is also great and this is the first device I’ve used that can keep up with my (from memory) impression of the Mojo in this aspect. The slightly warm, smooth and airy presentation makes it a great pairing with IEM’s and headphones that can come across as a bit strident on many other sources but this also leads me to believe that the treble may be a bit rolled off. That being said this is nothing that my 44 years old ears have any problem with and I don’t really miss anything but rather find the treble presentation in total to be one of the best I’ve ever heard in a portable source.
 
The overall presentation has a very good soundstage in all directions and layering is also great as is the amount of air between instruments. The laidback sound gives a sense of very good separation and black background (or maybe it’s the other way around?). Overall resolution, transparency and detail retrieval is great and this combined with the otherwise relaxed sound makes for a great “expensive” sounding overall experience leading the thoughts to both the LH Labs V2+ (bass) and Chord Mojo (treble) which are both amazing devices to me.
 
The difference between single ended and balanced output is less than on some other of my devices (Geek Out A2 and V2+) but still noticeable. Through the balanced output I find the background to be even calmer, making the separation feel better, and soundstage is also slightly wider. Not a day and night difference by any means but still an improvement. Please note that this will also depend on you IEM’s/earbuds/headphones as some of them seem to respond more to be running balanced than others.
 
Comparison:
Please note that the comments in the comparison section are not in absolute terms but in comparison between subject A and B. This means (as an example) that if subject A is found to be brighter than subject B it does not necessarily mean that subject A is bright sounding in absolute terms. I hope this makes sense.
 
In these comparisons I’ve been listening through my Hifiman HE400i’s.
 
I don’t really have any DAP that’s a natural comparison to the Opus #1 so instead I’ve chosen to compare in to my favorite amp/DAC that pairs well with Android (yeah I’m a sucker for Android-Fi ). Naturally I’ve compared them on sound related features only.
 
LH Labs Geek Out V2+ Infinity ($649) vs the bit Opus #1:
The V2+ is my favorite portable device so far and I’ve been using it a lot combined with a retired LG G3 phone as source. The V2+ ($499 for the non-Infinity offering) is in the same ballpark as the Opus #1 when it comes to price and does also offer both single ended and balanced output. Paired up with a phone it’s about the same size as the #1 as well so I figure it would be a good comparison
 
Compared to the Opus #1 the V2+ is more up front and energetic in its presentation. It’s also a touch brighter through the whole frequency range while the #1 comes across as more laid back and with more air between instruments as well as a darker background. Overall tonal balance (presence of bass, midrange and treble) is very similar but the #1 is overall softer and more relaxed. As an effect of this the treble on the #1 is also a touch less strident and smoother. They both offer excellent clarity and resolution and the #1 has a slightly wider soundstage while the V2+ is more focused and distinct. Bass presentation is similar on the two both when it comes to presence and quality and to my ears they both have among the best bass presentation that I’ve heard from any portable devices.
 
Moving to the balanced output the improvement of the sound is greater on the V2+ than on the Opus #1 to my ears. From the balanced output the overall sound is even more similar as better separation and a darker background is noticeable on the V2+ from its balanced output. Because of this the V2+ is more relaxed using the balanced output which makes it more similar to the #1. There’s also less difference in soundstage width from the balanced output of the two. The most noticeable difference between the two from the balanced output is that the V2+ is still slightly brighter in comparison, although I’d not describe any of these units as bright sounding per se.
 
The V2+ Infinity has some very low background hiss when used with my most sensitive IEM’s but hiss is even less audible with the Opus #1.
 
Matching:
The output impedance of the headphone out on the  is rated to a quite low 1Ohm from the balanced output and 2Ohm from the single ended output which should be low enough for it to work well with pretty much all kind headphones and even very sensitive IEM’s. The fact that the balanced output has lower output impedance compared to the single ended one may make it a better option for multi BA’s and hybrid IEM’s. Since getting balanced cables for IEM’s is a lot cheaper than for full sized headphones this seems like a good solution to me.
 
The Opus #1 also offers three different gain settings which helps even further when using it with a wide variety of IEM’s, earphones and headphones. To make matching even easier the volume features a full 150 steps so with three gain settings and small changes within each of them flexibility is pretty much top notch to me.
 
Despite not having any monster specs on the power output the #1 has enough power to drive all my full sized headphones fairly well. This includes the AKG Sextett’s with its 600Ohm impedance, although I’d have to crank the volume all the way up to 125 out of the 150 volume steps in balanced mode to reach my preferred listening level.
 
In this section I’ve tested how some of my favorite headphones but also one earbud and one pair of IEM’s pairs up with the Opus #1.  
 
Grado SR325is ($300):
The 325’s are quite easy to drive but does certainly scale with a good source and are revealing enough to show the difference in sources. The laid back and relaxed presentation on the Opus #1 suits the up front, mid centric and highly detailed characteristic of the 325’s like a glove. Every detail is there and the wide presentation of the #1 is a welcome addition to the 325. The 325 can be quite strident in the upper frequencies with a lot of sources but the #1 does a very good job as making them sound fairly smooth while still maintaining excellent extension and details. I think this is the best I’ve ever heard my Grado’s and I’ve not enjoyed them as much in a very long time.
 
Hifiman HE400i ($449):
Listening to the HE400i with the Opus #1 is very much similar to that what I experienced with the Grado’s. The Hifiman’s are definitely harder to drive compared to the Grado’s but still well within the comfort zone for the “, especially through the balanced output. Once again the smooth, detailed and ever so slightly warm sound from the Opus #1 makes these headphones really sing. The HE400i’s has an adequate soundstage width for an open headphone and the wide stage of the #1 makes it reach its full potential. The bass hits hard and deep and the treble is airy and smooth. The HE400i can be slightly strident in the upper frequencies with some pairings but none of that shows with the #1.  In total I’s say this is a very nice combination.
 
LZ-A4 ($195):
The A4 is a 16Ohm triple hybrid IEM (1 DD + 2 BA).  The A4 isn’t really very picky to sources in my experience but at the same time it’s revealing enough to show differences between them. I’ve used the A4 with a balanced cable, taking advantage of the #1’s best output, in this listening session. Paired with the #1 the A4 get to release the full potential of its excellent wide stage and its bass is also performing the best I’ve heard it. The A4 is never harsh or fatiguing to start with and certainly not when paired with the #1 but it does never feel too laid back and relaxed either. In total this is a great combination for my preferences and most definitely one of the best pairings that I’ve tried with the A4’s.
 
VE Zen 2.0 ($138):
The Zen 2.0 is a 300Ohm earbud that I like a lot and tend to use instead of closed headphones. It’s also a reliable travel partner for me when I stay in hotels and don’t have any full size cans around. The soft and smooth signature from the Zen 2.0 fares really well with the airy but yet detailed and transparence presentation from the Opus #1. Bass presentation is also really good with this pairing and in total this is also a great combination.
 
To sum up the matching section the signature of the Opus #1 works really well with all the headphones and IEM’s I’ve tried it with. . There’s also a very low background hiss even on the lowest gain setting when paired with my most sensitive IEM’s that might be worth noticing. It does also have enough power to work very well with most full sized cans.
 
Summary:
This will probably not come as any surprise but the bit Opus #1 is a fantastic DAP in my opinion.
 
For a long time now I’ve been an Android-Fi guy since it has been my impression that pairing an old phone with an USB DAC/amp has been the best way to get as much value as possible both when it comes to sound quality but also user interference, the Opus #1 is the unit that have changed my mind about this. Fortunately the #1 runs on Android so I can still declare myself as an Android-Fi fanboy
 
I’ve had a list of features that was crucial for me if I should take the step to pay for a solid mid-tier DAP instead of a phone combined with a DAC/amp and this list included: balanced output, USB DAC functionality, large memory capacity, digital output, line out function, good enough battery and of course great sound quality, solid build quality and stable operating system. After the latest FW update I find the Opus #1 to give me all of this. The only thing I could possibly want in addition would be the ability to connect it to Wifi and Bluetooth but I would not be willing to compromise on battery life to get there.
 
The bit Opus #1 is so versatile and great to me that if I was to have only one source it would be the one I’d pick among the gear that I own, not because it’s a Jack of all trades but because it’s one excellent performing DAP!
 

 
I'm sorry for the picture quality, it's really difficult to get it right this time of the year due to the lack of daylight.

Intro :
 
I had been away from the high-end DAP market for a long time until my Fiio X5 died and I was in the market looking for a new player. Though Ive never been a huge fan of the high end or ultra-high end DAPs (read-400-500$ and above) since I usually  sensed beyond that price range the returns are much lower going by the diminishing law of returns in most audio gear.  But after trying out some of the new players in the market I have been taken by surprise to find the super value the some of the new mid-tier brands have been offering .The kind of sound I would only expect from a 1000-1200$+ range player few years back.
One such player I recently tried out was the Audio-Opus,  Opus #1. I had never heard of this Korean brand until my friend toxicdrift(on head-fi) told me about it and was generous enough to loan my his personal player for this review and I am glad that I found this brand and player . To know why, read the review below.
 
Specifications :
 
  24bit / 192kHz High Resolution Sound
  32bit processor core
  Cirrus Logic CS4398 x 2EA Dual DAC
  ARM Cortex-A9 1.4GHz, Quad-Core CPU DDR3 1GB
  SNR 115dB, THD+N 0.0007%, Crosstalk – 130dB, Output 2Vmrs
  Low-clock-jitter sensitivity: 50ps(Typ)
  4inch TFT Wide Touch Display (480 x 800)
  WAV, FLAC, ALAC, AIFF, DSD, WMA,
  MP3, OGG, APE(Normal, High, Fast)
  Internal Memory 32GB
  External Micro SD Card Memory 200GB x 2EA
  Enhanced ABS Solid Body and Tempered Glass
  Ultra Power Saving Mode
 
Complete details can be found on their site : http://www.audio-opus.com/?page_id=15881
 
Packaging and Accessories:
 
The all black box and packaging is simple yet classy . No tacky graphics or design on the packaging.  Upon sliding the outer cover and opening the box you find the beautiful player staring right at you. Beneath the player you can find the minimal accessories which includes the USB cable, screen protectors and the user manual. Opus does sell the genuine leather case separately for 50$ which is a pure work of art so anticipating that as a stock accessory is not expected  but  a simple protective silicon type case would have been a great addition .
 

 
 
 

 

 
 

 
 
Design and Build Quality :
 
The player’s design is pretty simple and elegant with a rectangular shape and angular edges but a lot of people might find it odd and not to their liking , it’s a very subjective thing I guess. Personally I fell in love with the overall subtle design and feel of the player.
 
The design does somewhat remind me of the Astell and Kern players and even though it does look like a single piece of CNC machined metal body its actually made from ABS plastic with glass finish at the back .The tough tempered glass seems to be scratch resistant. The advantage of not having a metal body is that the overall weight seems much lower than other high-end players I tried recently like the Aune M2 pro.
 
In terms of ergonomics I find it perfect to hold and use .Especially the placement of buttons is convenient with the volume buttons on the top  left and playback buttons on the top right sides. The power buttons on the top side along with the headphone and balanced out .  There are 2 covered microSD slots at the bottom left side which I feel should be a standard on every high-end DAPs instead of a single slot since all these FLAC and WAV files do take up quite a lot of space.
 Rest of the operations are part of the beautiful UI on the 4 inch TFT screen which is not something exceptional like today’s high-end android phones but it pretty much does the job.
 
Overall the design is not as stylish, futuristic and distinguished which makes the asymmetrical A&K players stand out but it does pack its own weight and balance in terms of beauty and aesthetics with the low weight and plastic which doesn’t compromise on the looks or build . Infact quite a few of my non-audiophile friends loved its design which they usually don’t approve of when they see the bulky bricks of high-end players . 
 
 

 
 

 

 
 
 

 

 

 
 


 
Features , UI Battery life etc :
 
The UI is built on a stock android OS I believe and is pretty flawless .Not at all half-baked like some of the Chinese players out there. Browsing through music, fast forwarding, using play lists is all smooth and snappy .I personally haven’t come across any bugs in the UI during my limited usage.
Boot up takes 15-20 seconds and on booting it takes you directly to the playback screen instead of a menu . It resumes from your last track. There are two small icons on the top corners which take you to the media library (left icon) and the quick handy settings on the right icon which consists of EQ , balance out switching , sleep function  and screen brightness adjustments.
This settings menu takes you the main settings which has other options like Left/Right fader etc.
There’s a 10 band EQ with the option to save 3 custom settings but no pre-sets. I rarely play around with EQ except for minor adjustments so can’t comment much on that but the manual EQ does take few seconds to kick in and is not instantaneous .
 
The player supports pretty much all major codecs and music formats like Native DSD256 24bit/192KHz, WAV, FLAC, ALAC, AIFF, WMA, OGG, APE etc  .  There is no USB DAC functionality as of now which can be a drawback for some. Maybe it can be added in the future via firmware upgrades.
 
The beefy 4,000mAh/3.7V Li-Polymer battery returned good 8.5-10 hours of playback time for me , depending on the files I played.  Charging it from 0 to 100% took close to 3-4 hours . A faster quick charging feature could be great .The power saving feature and standby time on the other hand is remarkable.
 
 
 
 
Sound Quality :
 
Most high end DAPs usually end up putting a smile on my face for two reasons – either for being extremely detailed and analytical without being dry and giving you the instant upgrade in dynamics and clarity or  sometimes cause of a smooth , close to warm sound which isn’t too colored and yet doesn’t compromise on the detailing.
 
The Opus #1 I would say gives me the best of both worlds. The instant reaction was damn the soundstage is huge. The instrument separation, depth and texture detailing in the upper bass and lower midrange is phenomenal. Usually not something I notice when going from a mid-level player like Fiio X5 to something double its price.
 
Speaking of sound signature when I say warmth, there’s just a small hint of it in the right amount. Infact most would find the interpretation to be close to neutral but not analytical and hence it could rightly be classified as a Mastering Quality sound . What I like is its neither dark nor aggressive which was fresh relief from my existing FiiO  that I had been using and the Aune M2 pro that I had tried recently. Both of which I do enjoy  but the Opus 1 seemed to be pleasant change which made the listening experience a bliss.
 
The bass is great, one of the best I've heard in this price range. Haven’t noticed such texture and bass reverb on my IE80 otherwise.I guess the very tight and linear bass  of the player balances out the bass heavy IE80 and makes it sound perfect. I didn’t notice any mid bass oomph or added punch .The sub bass extends pretty low without trying too hard or overpowering.  Its punchy in the right quantity and well separated from the mids.
 
The midrange is I think the highlight of the sound with clean and full bodied sound .  Great transparency and a very intimate feel to the overall midrange - instruments and vocals  make the Opus sound beautiful and enjoyable.  The midrange just feels alive yet neutral and not too analytical or aggressively engaging. The smooth and natural sound should work with almost any headphone / IEMs.
 
Moving on to the treble extends well but not too bright or edgy and infact might seem less brighter than a lot of other players which may be a good or bad thing depending on your preferred sound signature or headphone but there is no compromise on the clarity and transparency in the treble. Some may find it laidback but definitely not lacking .
 
The sound stage is wide as I mentioned earlier but not too airy and depth is good enough, nothing phenomenal.  Yet overall the sound stage is one of the best Ive heard in this price range. The silent and black background phases in songs is amazing.
 
Overall the whole sound presentation of Opus is perfect for live music or electronic music which I listen to most of the time.  Opus seems to have played safe with the sound signature and not create something too unique or a signature sound which works perfectly fine for me . The clean , open and neutral presentation just works . The detail retrieval  , dynamics and texture do give you a major sense of upgrade if you are coming from a 250-400$ range DAP.  
 
The Opus 1 could drive most of my collection of HD 598 , Grado SR325i ,Denon AH-D5000 , AKG K702 etc really well . It’s not extremely powerful but not lacking in terms of driving factor. If you own a pair of cans which are extremely difficult to drive you may have to add an amp but  for most others there wont be need any . Infact you would rarely be touching the upper digits of the volume unless you listen to your music really loud.
 
Final thoughts :
 
An all-rounder and super value for money DAP is what comes to my mind after experiencing the Opus #1.  No particular features seem be lacking .Top notch finish and build quality, no half-baked UI or OS. Great sound quality for the price. Storage capacity is high, the whole experience is snappy and smooth.
 
Its sound quality is close to pro probably on par with the Aune M2 pro which I have been using side by side with the Opus but as a complete package in terms of the price /performance + features ratio , the Opus is very close to what the music lover in me has always wanted without dropping 1000$+ on a DAP.
 
If you own a pair of great headphones or IEMs which could benefit from a DAP upgrade you should definitely consider the Audio-Opus Opus #1.