CARY AUDIO AiOS digital music system
+ A Swiss Army knife of hi-fi components; especially good as a Roon Ready endpoint with MQA, up to quad DSD and PCM streaming solution; likeable, bold and easy-to-listen-to sound which doesn’t give up much to separates; power amp section is very good for the price class, with the classic house sound.
– DAC gives up a little tonal colour to the best in the price class. If you are looking to upgrade in future with separates, it will likely become partly redundant. Best matched with dynamic, neutral speakers that have well-controlled bass characteristics.
CARY AUDIO is an established brand with some very well regarded audiophile components, especially in the space of valve amplification. Not resting on its laurels, it has been also forging a formidable reputation in the digital space, with DACs and streamers which have been well received in the US and further afield. It is therefore a logical next step for the company to move to this product – the AiOS (All in One System).
Branded a “lifestyle system” it is styled in a more living room friendly manner, with curved top and bottom plates and a more friendly fascia, though I do think the design could be a little more tasteful in terms of the graphic design. You can also choose optional coloured side panels to better match your interior. The case is compact, but lifting the unit will surprise you with its 6.8kg weight, the biggest contributor being a nicely specified toroidal transformer.
As you might have guessed from the name of the product, it really is an all-in-one System, comprising an advanced digital streamer, DAC, preamp and power amp in its compact case. The streamer is a uPnP capable device, as well as Spotify Connect, Apple AirPlay and Roon Ready – it has a companion iOS and Android control app. I would only wish it also had Google Chromecast capability to round out its already considerable capabilities.
The DAC is based on an AK4490EQ, which currently can handle PCM signals up to 24-bit/768kHz, quad rate DSD and even MQA decoding. As an additional trick, Cary has designed the digital section to be able to convert and upsample any input signal into PCM up to 768kHz or up to quad DSD. The design is single-ended, however, not fully differential.
Inputs are via the network, SPDIF co-axial, Toslink optical or Bluetooth audio input (Apt-X capable). There is a USB-B input, but this is only for servicing and not audio, and therefore cannot be used as a USB DAC. Network connectivity is via dual antenna WiFi or wired Ethernet. Three USB-A ports as well as one SD card slot will also accept hard disks and SD cards with music files on them which can be browsed and played using Cary’s DMS app.
There is also a capable preamp section which will accept single-ended analogue inputs (two RCA phono inputs and 1 3.5mm minijack) and provide enough gain for those with source components which have 0.5-1V nominal outputs. However, it doesn’t have a phono input, which would have really made this truly all-in-one, but presumably, Cary was not keen to compromise on a hastily executed phono stage, of which it has some great examples in its stable (the PH-302 value phono stage comes to mind).
In any case, there is a plethora of affordable external phono stages that can be connected to one of the two line inputs. I tested phono playback via an ADL GT40a as well as EAR 834P phono stages. Preamp outputs are also plentiful – SPDIF coaxial out, Toslink out as well a single-ended analogue pre-amp outputs for L,R and subwoofer. As a bonus, the amp can also output Bluetooth to powered speakers or more likely, use with Bluetooth capable headphones. The preamp will also digitise incoming analogue sources for distribution to the digital preamp outputs. There is a facility also to apply EQ curves digitally, and I tested this, but did not use them for serious listening.
The power amp section is a classic Cary 75 watts per channel stereo Class A/B design, said to be based on one of its classic power amp. Outputs are through four binding posts, though they are set more closely than on some audiophile amps, so those with large gauge speaker cables may find it a little cramped.
Curiously, the AiOS has no wired headphone output, which is a notable omission as head-fi has become very fashionable. You can, of course, pair Bluetooth headphones to its Bluetooth transmitter for personal listening.
Set-up was super simple – plug in the three antennae (two for WiFi, one for Bluetooth). Plug in network (if you have it), power via the IEC mains socket and then your speakers, preferably via 4mm banana plugs. Done in five minutes!
I had no issues with network via WiFi or by Ethernet. There were no issues with Bluetooth either.
With such a capable unit as this, I tested it in a number of ways, starting with the most likely use cases:
- As an all-in-one streamer with Harbeth LS3/5as, KEF LS50s, Q Acoustics Concept 500s and Audio-Note AN-Es. Inputs via Roon Ready streaming, uPnP, Spotify connect and Airplay.
- As a DAC and amp, fed from a MacBook Pro’s optical output, and an Oppo BDP 103’s digital output to the same speakers as above.
- As an analogue preamp and power amp, fed from a Mytek Brooklyn DAC+ as well an EAR 834P and an ADL GT40a from my turntables.
- As a streamer/preamp from digital and analogue sources to a venerable Pioneer A400 as a power amp as well as digital out via Bluetooth and optical Toslink to a pair of KEF LS50 Wireless active speakers
The AiOS, out of the box, delivers a big and bold sound, but with an hour of warming up, it starts to really get going, with a smoother and more spacious soundstage. Going back to my listening notes, the over-riding characteristic is a slightly warm sound, with a large bass and solid imaging. It did best with speakers that are little leaner and flatter in the mid to upper bass – with warmer sounding speakers and those with bass humps e.g. LS3/5as, it could come across as a little too warm for some tastes. But with all partnering equipment, soundstaging was large with great dimensionality. Referring back to the sound of a friend’s Cary amps, the AiOS really carries the Cary house sound – easy to listen to, with plenty of detail, good soundstaging and musicality, just perhaps not quite as detailed or as transparent as its costlier valve stablemates.
Specifically, with the HD tracks download of Miles Davis’ Kind of Blue PCM 192/24, Davis’ horn is well imaged with Paul Chamber’s bass plucking clearly imaged behind, and supporting piano and saxophones from John Coltrane and Cannonball Adderley imaged to left and right, at the extremes of the speakers. The AiOS has a very musical sense of flow -never forced or hurried and although not the most detailed, the detail is well rendered in the context of the music and the musicians.
Switching to Dave Brubeck’s Take Five, also 192/24 PCM download, imaging of the left-centre-right soundfield was well done. Rhythmic pace was good, though not as quick or on the mark as a Naim Uniti Atom. With leaner speakers, its rhythmic capabilities are better appreciated.
With vocals, a HDtracks 24/44.1 download of London Grammar’s Hey Now was stunning, with the AiOS able to project a solid and palpable image of Hannah Reid’s luminescent voice, layered with instruments above, below and behind. Bass was fulsome given the warm tonal balance, but never seemed excessive.
Comparison between a SACD of Bill Evans Trio’s Sunday at the Village Vanguard and the recent Mobile Fidelity One Step 45rpm reissue of the same album shows that a more natural soundfield is well spread across the speakers, especially the sound from the audience is placed well behind and around the trio. Conversation and the tinkle of plates and glasses are distinctly rendered without taking away or masking the amazing music coming from Bill Evans, Scott LaFaro and Paul Motian. The vinyl replay was excellent both via the ADL and EAR phonostages, but I preferred marginally the ADL as it had a drier character which did not over-emphasise the AiOS warm leanings. The EAR phonostage has a similar “big and slightly warm” sound and although was pleasant to listen to, it came across as a little too warm for my taste via the AiOS. The vinyl replay also then brought up a difference in character vs the DSD playback of the same track – it seemed much quicker and fleet of foot with a bit more transparency – more on that later.
MQA streaming from the handful of MQA tracks I had on hand (mostly downloaded from 2L’s excellent test track repository) showed a very subtle effect of non versus their non-MQA encoded versions. The MQA tracks showed a little more rhythmic ease and a little more light in the midrange and a more delicate high end especially on cymbal work, but I would not say that it was a super obvious difference. MQA streaming via Tidal Masters showed similar differences between 16/44 and MQA versions of the same tracks. Testing versus the MQA certified Mytek DAC showed again that there was a slight loss of tonal colour with the AiOS MQA decoding.
Using the AiOS as a preamp and power amp, bypassing the DAC, revealed that perhaps the analogue stages have a bit more capability than the DAC itself. I played the same tracks and others through the Mytek Brooklyn DAC+ through Roon Ready – it was simplicity itself to switch between the two DACs to compare once I had equalised the volume between the two sources.
Be clear that the internal AK4490EQ DAC acquits itself well – especially if you take advantage of its ability to upsample digital inputs. But comparing the Mytek as an external source, my suspicions from the vinyl playback sessions were confirmed – the Mytek had better pacing and rhythm, a tighter and less warm bass coupled with a bit more top end air and depth to the soundstage, though the soundstage itself and the solidity of the instruments and players were diminished slightly. But the most striking difference was that the Mytek rendered instruments and voices with more tonal colour than the internal DAC – saxophones sounded richer, human voices had a tad more inflection and drum strikes had more variation. I suspect therefore that the AiOS preamp and power amp sections are actually very capable indeed and more transparent to the source than their humble provenance may suggest.
Switching gears and using it as a streamer (mostly with Roon) to a Pioneer A400 as a power amp showed that the internal DAC does a good job as a streamer and also as a non-streaming DAC especially when coupled with a leaner and drier sounding power amp. Although the tonal colour did not come back entirely, it was much easier to make out differences in the tone of John Coltrane’s instrument vs Cannonball Adderley’s on Kind of Blue for example. Experimenting with the up sampling settings were also quite subtle – suggesting that Cary has thought out its digital filters well. Straight processing of tracks was generally the most dynamic, but upsampling them to quad DSD usually made them a little smoother and broader, with more delicacy in the top end. I think this is a question of taste. Upsampling in the PCM domain showed less marked differences, and retained the dynamics well, smoothing out the top end a little.
I also tested the digital output via Bluetooth and optical to a pair of KEF LS50 Wireless and purely as a streamer, the AiOS is certainly very good – on an optical connection there no real discernible differences vs streaming directly to the active speakers. Via Apt-X Bluetooth transmitted from the AiOS, there was a slight loss in fidelity, especially in the top end and a slight hardening in the midrange, but nothing that was egregious and perfectly listenable in a causal setting.
I used Cary’s DMS streamer app (also used for its DMS-500 high end streamer) as well as Roon Remote to control the AiOS. I did not try, but uPnP controllers should also work well e.g. Bubble uPnP and Jriver.
Cary’s own app is functional and works smoothly enough – with few hiccups and crashes, though I would have wished for a slightly better UI design in terms of differentiating buttons and functions. Roon Remote worked superbly well with the Cary as well, waking up the unit and controlling functions well. However, to see more details and to set digital filters, you need the Cary app to do that.
The Cary also comes with an IR remote control, which I only used basic functions as app control was much more feature rich. Note that it uses the same IR control set as Arcam amps – so it interfered with my SR 250 in terms of volume/muting commands.
I pondered this for a while. As a so-called “lifestyle” product, it works, though it could do with a little more polish with the smartphone app and the unit’s display could be a bit more home- and user-friendly – but I think most households would find this unit not too hard to blend into an interior and all members of the family would find it easy to use especially via Spotify Connect.
THE LAST WORD
For the casual audiophile who has graduated to online streaming music via Spotify, Tidal etc., this makes a lot of sense as a one-box solution – just add a good pair of speakers, preferably ones that are not too tonally warm, to complement the inherent characteristics of the AiOS.
But its utility and its abilities are much more profound – and it can be the jack of practically all trades. That it is master of none is the issue for the more dedicated audiophile – who would probably like separate units for streaming, DAC, pre amp and power amplifier sections. But they would then lose out on the superb functionality and integration that the AiOS and others of its ilk have with modern sources of digital music.
I would recommend the Cary Audio AiOS to friends who are principally music lovers who want a great way to play back their music – the unit is musical, pleasant and still detailed enough to satisfy all but the most exacting audiophiles. It is especially good for those who have already invested in a Roon streaming set-up and have a Tidal Hi-Fi account. This, as well as having MQA and CD quality streaming on tap, makes this a music exploration device that is hard to beat.
For more exacting audiophiles who are more keen to experiment with components, this might make the hub of a great second room system.
Sources: Denon DP-80 direct drive turntable, MicroSeiki MA-505X arm with Hana SL, ZYX Omega Premium MC, Miyjima Labs Kotetu Mono MC cartridges; Roon Server on SonicTransporter i5 feeding a Sonore MicroRendu driving a Mytek Brooklyn DAC+ via USB; Sony HAP Z1ES HDD player / Amplification: EAR 834P phonostage with Denon AU320 SUT; Project Phonobox RS; ADL GT40a Phonobox; Arcam SR 250; EAR 859 single ended triode, amplification / Speakers: Audio Note AN-E; Q Acoustics Concept 500; KEF LS50; Harbeth LS3/5a / Wires: Belden, Kimber Kable interconnects; Isoda Electric Speaker Cable, QED Reference XT40 Speaker Cable
Johan Khoo is a business consultant by profession but an electrical engineer at heart. He has been building, tinkering with hi-fi and audio equipment since his teens. Loves jazz, classical and classic rock.