Grand Opus
The new Opus 2 portable digital audio player boasts a host of features - and is one of the best sounding on the market, says Noel Keywood.
The Opus 1 portable digital audio player (DAP) I reviewed in our August 2016 issue was solidly built, smooth in its sound, easy to use and best of all costs a reasonable £499. The new Opus 2 by way of contrast costs £1250 or thereabouts, so this is a premium player. What could its Korean manufacturer TheBit possibly add that could justify such a price I wondered? Their website (www.audio-opus.com) soon made this clear. Where the Opus 1 uses a Cirrus Logic CS4398 DAC chip, the Opus 2 uses the more expensive and prestigious ESS Sabre32 series 9018K2M (portable version). It also possesses wi-fi for easy firmware upgrade, and Bluetooth so music can be streamed wirelessly to the hi-fi – providing it has a Bluetooth link of course. TheBit say it has Mastering Quality Sound (MQS), but this simply means hi-res ability, not to be confused with Meridian's MQA digital file authentication system. The Opus 2 is chunky and solid. Measuring 83mm wide (not 76mm as the website thinks), 125mm high and 18mm deep, it will not fit a shirt's top pocket; this player is for a strong trouser pocket, or a bag. On our scales it weighed 254gms and anything over 200gms I rate as heavy. The reason is an ESS 2018K2M chews current and needs a big battery, so to get 9 hours playing time a 4000mAh Li-polymer battery is fitted where 3000mAh is common. Add in a chunky machined alloy case and large TFT 4in touch display panel of 480x800 resolution and you end up with a sizeable player. It had a turn on time of 25 seconds. The Opus 2 has a protected, side mounted rotary volume control that is definitely a plus point: it can be twiddled in the pocket without looking. There are 150 discrete levels so resolution is good, and at maximum (150) the player delivers enough output from its 3.5mm headphone socket to drive headphones loud. This same socket also has an optical digital output hidden away inside, for which you need a small, cheap, plastic plug-in adaptor (available from Maplins) into which an optical Toslink cable can be inserted.
Press button controls for Play/Pause and Track Skip at left, with miscroSD card slot and microUSB socket at bottom. A drawback of this is that the optical input receivers of many DACs work to 24/96kHz maximum, so play a 192kHz sample rate file (24bit) and the system falls mysteriously silent. I value the presence of a digital output because it allows me to hook up a player to the hi-fi via a mains powered DAC, bypassing the battery powered audio output stages that, as good as they may be, never match mains powered circuits in sound quality – always short of dynamic punch. To the right of the headphone socket lies the strange and almost unusable 2.5mm four-pole socket that offers balanced output (also used by Astell&Kern). I spotted what looks like an adapter and a pair of XLR line plugs on the website, so balanced analogue audio can be taken to the hi-fi if you obtain these bits, but digital linking is preferable. You can also connect up headphones balanced as I did with my Oppo PM1s, for slight improvement in sound quality if, that is, you can get hold of a suitable headphone cable terminated with a miniature 2.5mm four-pole plug.
At top sit a 3.5mm stereo headphone socket, with coaxial digital output, and 2.5mm four-pole balanced output socket.
I soldered up such a cable some time ago, using an illuminated bench magnifier (Maplins again) and it was difficult. The plug body is too small to accept twin screened cables. Also, the plugs are so weak they snap in use! So you can get balanced sound – but not easily, nor for very long. There is 128GB of internal memory and one microSD card slot that will address up to 200GB. An ARM Cortex quad-core A9 processor handles all processes, making the Opus 2 fast and slick to use. Its user interface is easy enough to handle, helped by a swipe down screen with all main functions on it, as well as the inevitable Settings menu. All the usual options such as Gapless playback, Equaliser and what have you are provided, but there are no filter options. There is a USB DAC option, however, that allows the unit to be used as a quality headphone amp with a computer, connected through its microUSB input/charging cable. All the usual file formats can be read, including WAV, FLAC and Apple's ALAC and AIFF. There's OGG and APE too, as well as DSD (64&128) with the DFF and DSF file tags. SOUND QUALITY The Opus 2 sounds in a nutshell big, powerful and exciting. It drew me in immediately; within minutes I was in a place that was very good audio wise. Portable players these days all do a good job and it is difficult for one to stand out but the Opus 2 did and sort of in the way expected of the ESS Sabre32 series DAC chips. Meaning it was organically rich and smooth, better textured in its sound than others. Tracks I play regularly for review purposes all grew; the voice of Lucia Gomez singing Lucia (24/96) was closer and more complex sounding: I found her more engaging than usual whilst the wooden block on one channel and accordion on the other had a stronger presence through sheer force of realism. All this is what I expect to hear from Sabre32 DACs well implemented. However, headphone drive chips and power supplies are an issue on portables, the latter little talked about, but low battery volts must be stepped up with modern dc-dc convertors and there's plenty of leeway to mess up here. I suspect it is in this critical area that TheBit have done a better job than most, allowing the 9018KM to really fly. Because another feature that grabbed me of this players sound was the width of the soundstage, and its sense of depth and airiness. It brought life to any rock music where a microphone(s) had been used (i.e. most rock!) and also to classical where I had some surprises.
Swiping down brings up this screen of basic player setting options.
Benjamin Grosvenor playing Chopin's Nocturne No 5 in F Sharp, Op 15, No2 (24/96) I usually pass over as a trifle bland in quality and not revealing enough for a sound quality assessment yet on the Opus 2 it sprung to life not only as a beautiful piece of music superbly played but as a live and atmospheric recording too, brimming with detail, the piano stretching wide across a generous soundstage that possessed air and space, with a depth perspective. This so captured my attention that I listened intently to a whole breadth of classical music and found the Opus 2 brought out low level detail and atmosphere like no other, making it especially strong in delivering choral works like Eric Whitacre Singers Oculi Omnium (24/96). The Opus 2 doesn't have the hard-etched sense of time domain progression of Astell&Kern players, so much as packing a powerful low-end punch and perfect timing, obvious with the metronomic drum machine in Queen's Radio GaGa. Tracks with a bit of a rough edge in the recording (24/96), like Tom Petty's Refugee were better sorted out in their structure, messiness unraveled to go easier on my ear; suddenly Refugee was made by humans in a studio rather than being a simulacrum hatched up on a cheap PC. And as the all-analogue 1965 recording of Otis Redding singing Respect (24/192) hove into aural view (as it were!) I felt as if I was listening in the Stax studio as the song was being laid down.
Track menu information is easy enough to read, with cover graphics depicted.
The Opus 2 threw up a big wide picture of what was going on, with deep insight into Redding at the microphone and the Memphis Horns acting as accompaniment. Judging the player in absolute terms by comparing it to an Audiolab M-DAC+, connected via optical digital cable, there wasnt the dynamic contrast available to acoustic bass, tenor sax or cornet in Duke Ellington's Stompy Jones (24/96) to take one example, but otherwise the Opus 2 had much of the svelte richness of the mains driven Audiolab, that also has an ESS 9018 DAC inside of course. I don't think it is realistic to expect a battery driven device to be comparable to a mains unit, so this is no deal breaker; the Opus 2 still had the essence of the Audiolab. Moving from listening with Philips Fidelio X1 headphones to Oppo PM1s that can be connected balanced, I found the balanced output lacked the low-end drive and punch of the headphone output and I suspect it is purposed as a line output that needs to see a higher load than phones. It still sounded nice and clear however, with great instrument separation across the midband and pin-sharp imaging. CONCLUSION The new Opus 2 from TheBit is one of the best portable players I have heard to date. It has a wide range of useful facilities, is easy to use but most of all has fabulous sound quality that makes listening a riveting experience. This player is expensive, but the bits inside and the final sonic result justify it. If you have the money and the desire – get it! It will put you into the place the recordings were made.
OPUS #2 £1,249
OUTSTANDING - amongst the best
VERDICT A portable with fabulous sound quality. But expensive.
FOR - sound quality - ease of use - balanced analogue output
AGAINST - heavy - a tad bulky - small balanced socket
Advanced MP3 Players +44 (0) 343 289 6880
Rohde&Schwarz UPV advanced audio analyser, used for all measurements.
MEASURED PERFORMANCE Frequency response of the Opus 2 (192kHz sample rate) measured flat to a very high 91kHz so this is a wideband device, more so than most other players. However, the audible impact of such wide bandwidth is usually minimal, slower filtering commonly offering a better damped time domain impulse result. This is why players commonly have an alternative ‘slow’ filter, something the Opus 2 lacks. Output was healthy at 2.3V, more than enough to drive even insensitive headphones (magnetic planars) loud, if a little less than the 3V common nowadays. Dynamic range was high at 116dB, if not as high (120dB) as the Cowon Plenue S reviewed in March 2017 issue, so the Opus 2 is very good but not quite class leading, as might be hoped at the price. Distortion measured a low 0.035% at -60dB with 24bit and 0.24% with 16bit – both very good figures. Our distortion analysis shows a complete absence of distortion products, being a summation of noise. Output from the tiny 2.5mm four pole balanced socket measured 2.6V and dynamic range was again 116dB.
Frequency response 6Hz-91Hz Separation 94dB Noise -114dB Distortion 0.035% Dynamic range (24bit) 116dB Output 2.3V
FREQUENCY RESPONSE
DISTORTION
DYNAMIC RANGE (55.8+60=116dB)
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