Roksan Attessa streaming integrated amplifier

When I put together my first hi-fi system in the late 1960s, the amplifier was a Kenwood integrated. Soon I replaced the Kenwood with a Sony integrated, and then, a few years later, I bought a Lecson preamplifier and power amplifier pairing. It's been separates for me ever since.

However, a reader wrote this comment on Stereophile's website a while back: "It will be interesting to see if Stereophile catches up to the focus on active, integrated designs. The relevance of separates seems to be waning in comparison to these sexy and modern designs." The commenter was referring to fully integrated, active loudspeakers, but his point could equally refer to the increasingly common integrated amplifier that incorporates line and phono analog inputs plus a versatile, network-connected D/A section.

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In January 2020, I reviewed such a streaming integrated amplifier, NAD's Masters Series M10, which I purchased after the review was published. The M10's Dirac Live low-frequency room equalization made it a natural partner for my long-term reference standmounts, the KEF LS50s, which I had also purchased following a review.

So when Editor Jim Austin emailed me to see if I would be interested in reviewing a new streaming integrated amplifier, the Attessa from British manufacturer Roksan, which, like the M10, can be controlled with the BluOS app and is priced at an affordable $3399, he didn't have to ask twice.

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The Attessa...
... is housed in a slim, rack-width steel chassis with an anodized aluminum front panel. A large control knob dominates that panel visually. Rotating it controls the volume; pressing it mutes the outputs; pressing and turning it switches between inputs. This knob is said to give haptic feedback, ie, to vibrate when you use it, but I found this very subtle.

To the right of the knob is a horizontal, orange, thermometer-style, OLED volume display with a 3.5mm stereo headphone jack at the far end. To the knob's left is an array of input-indicator icons, each of which lights up orange when selected.

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The back panel has, on its far left, two pairs of loudspeaker binding posts; next come three pairs of RCA jacks, for a moving magnet phono input, and two line-level analog inputs, one labeled "Variable Input (No signal sense)," the other "Fixed Input with signal sense." Next to those is a fourth pair of RCA jacks, labeled "PRE OUT/SUB." Also found back there are several digital connections—two each coaxial and optical S/PDIF, an Ethernet port, two USB Type A ports—one is used for a Wi-Fi receiver—and a USB 3.0 port labeled "BLUOS SERVICE ONLY." The Attessa also accepts Bluetooth audio data encoded with the SBC, aptX, and AAC codecs.

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The Ethernet and Wi-Fi ports accept audio data sourced via the BluOS app. As well as playing back audio files from local storage, BluOS serves up a plethora of streaming services including Qobuz, Tidal, Amazon Music, Spotify Connect, Deezer, and TuneIn Radio. The Attessa's volume can be adjusted and its inputs chosen with the BluOS app or with the provided slim plastic remote control.

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The chassis interior is dominated by a massive, 400VA-rated, toroidal power transformer on its left and by the amplifier's printed circuit board, with its heatsinks, on the right. The power amplifier's output stages each use two pairs of complementary devices, these biased into class-AB. Between the transformer and the back panel are two stacked printed circuit boards carrying the digital S/PDIF input, Ethernet, USB, and BluOS receiver circuitry and the D/A processor. D/A conversion is handled by a Texas Instruments/Burr-Brown PCM5242 DAC chip, a two-channel sigma-delta part that's capable of handling sample rates up to 384kHz with bit depths up to 32, though the datasheet on the TI website quotes a S/N ratio of 114dB, which is equivalent to a resolution of 19 bits.

Setup
After installing the Attessa in my system and powering it up, I followed the setup instructions in the excellent manual. The first line of business was to install the MaestroUnite app on my iPhone. This connected with the Attessa and before I could continue with the setup, the amplifier updated its firmware. Once that was done, the app allowed me to choose the sensitivities for each of the Attessa's inputs and the headphone output and to customize the input icons. I stuck with the factory settings.

Although Roksan intends the Attessa to be a Roon Ready device, when I opened Roon 1.8's Settings/Audio page on my Mac mini, I got the message "There's a problem with this device. The manufacturer has not yet completed certification for this device." The rep from Roksan's North American distributor confirmed that they were waiting for full Roon Certification but reassured me that this will be updatable via firmware. I could still stream audio data to the Attessa from Roon using Apple's AirPlay, but as AirPlay is limited to 16/44.1k data, I used the BluOS app instead.

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When I ran BluOS for the first time on my iPad mini, it allowed me to name the Attessa, log into my Qobuz and Tidal accounts, and locate my favorite radio stations with the TuneIn function. When I selected "Library" from the list of inputs, BluOS found my network-attached storage and spent a while indexing the files. Once that was done, I was able to use BluOS to select albums, artists, composers, genres, songs, and favorites, as well as folders on local storage. The only idiosyncrasy was that with some locally stored albums, it played the tracks in alphabetical order.

To audition the Roksan's physical inputs, I connected my Ayre C-5xeMP disc player's single-ended outputs to the Attessa's variable line inputs and its coaxial digital output to one of the S/PDIF inputs. I regret, because of how well it measured—see the "Measurements" sidebar—that I have neither a moving magnet phono cartridge nor a step-up transformer to use with my Linn Arkiv B moving coil cartridge, so I wasn't able to audition the Attessa's MM phono input.

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Listening
I started my auditioning of the Attessa with it driving the Mission 770 speakers I reviewed in the November 2022 issue, which I had been powering with the Parasound Halo JC 1+ monoblocks. The news had just come in that pianist Lars Vogt had passed away, aged just 51. I used BluOS to cue up his performance of Brahms's Second Piano Concerto with the Royal Northern Sinfonia (24/48 FLAC, Ondine/Qobuz), a favorite recording.

COMPANY INFO
Roksan/Monitor Audio Group
North American distributor: Kevro International Inc.
902 McKay Rd., Unit #4
Pickering, ON L1W 3X8, Canada
(800) 667-6065
ARTICLE CONTENTS

COMMENTS
volvic's picture

I enjoyed reading this review, but was disappointed Mr. Atkinson could not find a step up transformer to listen and review the phono section of this amp. As an owner of one of their turntables, I was keen to read how well it could sound. I am hopeful for a follow-up.

John Atkinson's picture
volvic wrote:
I enjoyed reading this review, but was disappointed Mr. Atkinson could not find a step up transformer to listen and review the phono section of this amp.

I appreciate your point. However, it is fundamentally important for a product being reviewed that the reviewer not change anything else in the system. If I had borrowed a moving-magnet cartridge or a step-up transformer, there would then be another change to the system in addition to the Roksan amplifier.

John Atkinson
Technical Editor, Stereophile

EDunbar's picture

John: True, but some (several?) buyers who have a moving coil cartridge might be likely to add a step up transformer, even if it were a “basic” unit, if they were to buy the Altessa, so that is a real world configuration and it would be valuable to a review.

JRT's picture

The step-up transformer pair could have been kept in the comparison(s), using the same turntable, MC cartridge, step-up transformer pair in the LP playback subsystem, and using the MM inputs to the phono preamplifiers in both systems under comparison. No?

Maybe could have also tested the accuracy of the phono preamplifiers' RIAA filters using something like (James) Hagerman Audio Labs' iRIAA2 ($49+s/h).

Maybe in some future tests? This probably won't be the last device with a phono preamp on your test bench.

edit: I want to clarify that I do appreciate your subjective reviews and your efforts in including useful and interesting objective testing to the subjective reviews (yours and others), and do not want my disagreements, comments and suggestions to be misinterpreted as complaining about anything in your efforts in this. Sincere thanks for what you do provide. I just sometimes want more.

Kursun's picture

I believe it is an art form to design a good back panel, as well as the front panel.

In this example the speaker posts are tucked away into corner, cramped together along with a ground post.

A very poor design indeed.

Jack L's picture

Hi

I do not agree. BACK panel is for connection terminals. Function is the top priority over "art form" !

This is a pretty decent back panel design: right hand side for digital &
left hand side for analogue connection terminals to reduce RFI/EMI noise emitting from the digital side to the analogue side inside the amp & the connection cables outside the amp.

"cramped together with a ground post" qtd Kunsun.

With audio output power only 80Wrms @8ohm/channel, no need large gauge size ground cable at all. So why "cramped together" ???

Jack L

JRT's picture

The manual for the Roksan Attessa states that loudspeaker cable assemblies terminated with 4mm banana plugs are the Roksan's recommended method of connecting loudspeakers to their amplifier. The binding posts each have a 4mm banana jack/receptacle at the end with a plastic plug which must be removed to accept the banana plug. The manual also mentions the alternative method of using unterminated loudspeaker cable with wire ends stripped bare and inserted into the binding posts, and further states that the binding posts may accept no larger than 12AWG wire, and they recommend using no smaller than 16AWG.

To your point, there is plenty of clearance if the recommendations stated in the manual are followed.

Jack L's picture

as I design/build phono-preamp & power amps for decades.

The problem is many readers here just want spit out whatever like or dislike without the right knowledge.

Jack L

JRT's picture

Roksan's Attessa integrated amplifier is available without the network attached streamed digital audio receiver-processor functionality for significantly lower price. That wasn't mentioned in the review, but a very cursory web search turned up some online vendors. I only looked at pricing from the first online vendor in the search results.

Without that added functionality, the vendor's asking price is $2.1k. With that functionality, $3.2k (article mentions $3.4k MSRP). Both versions include the DAC and Bluetooth. The networked streamed audio functionality could be provided by a separate component rather than the integrated internal component.

When this is out of warranty, out of production, an obsolete product, out of active support, no longer receiving regular updates/patches to software/firmware, the integrated amplifier functionality may continue to function for several decades until some internal electronics component eventually fails. Unpatched software/firmware in the network attached hardware may cause some big problems beyond the audio playback setup.

I am not confident that the network security patches will be promptly released as new malware and network security vulnerabilities continually emerge, especially after the product is no longer offered for sale new by the manufacturer. I wouldn't want something attached to my LAN sniffing packets and skimming passwords and other account credentials on my network. I would rather have a separate nonproprietary device providing this networked streaming functionality, something I can easily update and eventually upgrade or replace separately from the audio amplifiers, control preamplifier, DA converter, etc.

Jack L's picture

Hi

BINGO ! Great minds think alike !?

That's exactly what yours truly cheapskate has done since day one of streaming: no costly brandname all-in digital preamps/integrated amps which are always prone to obsolescene sooner if not later.

Being a vinyl addict, why should I spend any decent money for any digital audio ? So with very little money, I got a dirt-cheap no-name DVD player with LAN/streaming function/auto-upgradable firmwares, + a dirt-cheap DAC (24bit-192KHz). Yet they both serve me nice & neat on playing music CD/DVDs & allow me to watch any on-line classical music programmes - FREE via say, YouTube.

Play smart is the name of the digital game - never spend big bucks in it due to its every changing "vulnerabilities".

Listening is believing

Jack L

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