The Anthem STR line-up consists of a pre-amp, a power amp – and now, also an integrated amp. The pre/power impressed when on test a year or so ago. Can the one-box integrated deliver similar sonics in a more convenient form factor?
When Canadian firm Anthem launched the STR pre-amp/power amp combo last year, it reached for higher sonic ground. The duo was ambitious in both tech and sonic terms, and the results were musically engaging.
Now an integrated amplifier has joined the STR family, the idea being that it provides most of the pre/power’s facilities and capabilities, but in a single box. Not everyone has the space for a separate pre-amp and power amp, after all – and opting for the integrated has a pride advantage, too.
Like the pre-amp, the STR Integrated comes with Anthem Room Correction (ARC) built in, which promises optimum performance, regardless of speaker type or room acoustics. That’s a big promise to keep, though.
The power output is a little lower, compared to the pre/power, but the claimed 200 watts/channel into 8 ohms (and 400 watts into 4 ohms) still provides plenty of muscle and drive, even when partnered with less sensitive or low-impedance speakers.
AT FACE VALUE
The STR Integrated amp closely follows the design language established by the pre/power. The look is chunky and contemporary, with large alphanumeric display taking up almost half of the partly curved fascia.
A large volume controller is flanked by basic array of small, round switchgear, with most users expected to use the full-feature remote control for day-to-day use. All-metal casework and a hefty18 kg weight confirm the Anthem’s robust build quality.
As with the power amp, heatsinking for the Class A/B amplifier is internal, making for a clean, uncluttered look. Peer under the covers, and the large toroidal transformer is an obvious feature of the tidy circuitry.
The rear panel provides a good indication of the amp’s comprehensive feature set. In analogue terms, a single XLR balanced input set is joined by five single-ended RCA pair, and that excludes the separate moving coil and moving magnet inputs for the phono stage.
There’s also a full complement of digital inputs, spanning two coaxial RCA and two Toslink optical digital inputs, as well as an AES/EBU socket and an asynchronous Type B USB input. Audio outputs include fixed and variable RCA outputs, and dual subwoofer outputs.
Network connectivity is provided via Ethernet, and there’s also a mass storage-capable USB Type A port, while custom installers will welcome the inclusion of an RS-232 serial port, and 12V triggers. Robustly engineered binding posts complete the back panel offering.
UNDER THE COVERS
That large, centrally located toroidal power supply mentioned earlier is only one aspect of the STR’s meticulously laid out circuitry. The amp’s topology favours short signal paths and a high-current, high-output design that is stable all the way down to 2 ohms.
There are eight bipolar devices for each channel, and careful component selection and matching adds to the amp’s sonic potential.
The STR incorporates both a digital-to-analogue converter, and an analogue-to-digital converter, the latter to enable signal processing and application of the Anthem Room Correction system to incoming analogue signals.
The ADC converts incoming analogue signals to 192 kHz/32-bit digital signals, but users can choose to bypass this step, and to listen to the original, unprocessed analogue signal provided by the source component instead.
Digital data is automatically upsampled to 192 kHz/24-bit resolution, while the USB input will support higher resolutions: PCM up to 384 kHz/32-bit, as well as native playback of DSD 2.8 and DSD 5.6 material.
Setting up the STR integrated also highlights some of its unique features, notably the ability to convert incoming analogue to digital signals, and applying Anthem Room Correction. It’s important to note that ARC only works with signals in the digital domain, so analogue sources passing through without being converted won’t benefit from ARC’s attentions.
That large display makes sense once you embark on the menu-driven set-up process, which is intuitive enough – but the big display makes it all so much easier. Each input can be customised, and the options vary.
Even better, can you have different configurations for one input stored under different names, allowing instant switching between digital conversion and analogue pass-through, for instance – or the application of more than one speaker profile to the same input.
But the amp’s real secret weapon is its built-in ARC Genesis room correction, which includes subwoofer management. ARC is already considered the class of the field in domestic surround sound room calibration, and its introduction in a stereo role here brings all the benefits to music lovers.
One caveat: for the ARC settings to be activated, the incoming audio signal needs to be in the digital domain. That means that all analogue audio sources need to be converted to 32/192 PCM. You can run in conventional analogue, but it means the ARC adjustments cannot be applied.
The latest ARC Genesis is a lot more user-friendly than the previous version, and is also Mac-compatible for the first time. It really is plug and play, using the supplied USB microphone and stand.
You open the software, plug in the mic, follow the on-screen instructions, and in about 10 min, you’re done. You can also tweak the settings after the room has been measured, and save different settings in different profiles, then swap between them on the fly.
For tweakers and advanced users, there is a broadened, improved scope for target curve adjustment, and the measuring process can be interrupted, resumed or repeated at any stage, rather than having to start from scratch every time.
ARC can be used in three ways – using the free ARC mobile app in conjunction with the smart device’s own microphone; using the same app but with the microphone provided with the STR amp; and finally, employing the fully-fledged ARC Genesis software on a PC or Mac, together with the ARC microphone kit (calibrated microphone and stand) that’s also supplied with the STR.
The results are impressive regardless of method, and the mobile-based measurements are quicker and easier. However, it’s worth using the PC/Mac software and calibrated mic for optimum results. It also allows post-measurement adjustments of the measured target curve.
For this review, I performed a fully-fledged ARC Genesis calibration sequence using my 13-inch MacBook Pro. The process was seamless, quick and intuitive, with a clear interface and repeatable results.
I then configured the inputs to allow a direct comparison of analogue and digital signal feeds from the same sources (a Lumin D1 streamer, and a Marantz SA-KI Pearl Lite disc player) – in other words, allowing a comparison between the STR operating in analogue mode, and with digital conversion invoked and ARC applied.
To make the ARC’s task even tougher, I used a pair of KEF LS50 standmount speakers, linked to our Atlantic Technologies active subwoofer. ARC Genesis includes bass management, and the STR can run one or two subs in mono or stereo configuration.
First things first: once you’ve heard the impact of ARC on overall system sound, you won’t want to be without it.
The improvement in sound is quite remarkable, demonstrating in the first instance the pivotal role that the acoustic environment plays in system performance, and what benefits are to be gained from addressing the almost acoustic anomalies present in most ‘normal’ rooms.
Without ARC, the Anthem sounds bold and boisterous, with plenty of pace and muscle. It takes the music by the scruff of its neck and projects it with verve and vigour. The result is exciting and powerful, with broad staging and tidy, incisive imaging.
However, invoke ARC, and the changes are as dramatic as they are musically convincing. This is not a case of DSP-instigated hyperbole, but of optimising the performance to the ultimate benefit of the music.
Immediately apparent is the way the soundstage opens up, affording the music more breathing space. The sound image is allowed to extend across all three dimensions, with depth the most obvious beneficiary.
But height and width also become more generous, creating a musical picture that extends well beyond the boundaries of the room. It also allows large-scale works to attain the kind of presence and stature you’d expect of the real thing, even with bookshelf speakers and a sub, as tested here.
On ‘Riviera Paradise’ off the Sweet Release set by Reese Wynans and Friends, the amplifier delivered the sweeping synths and melancholy guitar with a fluid ease and inviting intimacy. The Hammond B3 sounded real and impactful, while the percussion was presented with precision and power.
Gentle electric guitar licks added to the appeal, while the STR also recreated the spacious, slightly reverberant ambience of the recording with confidence and credibility.
I was particularly impressed by the staging, which was almost palpably three-dimensional, allowing precise positioning of the ensemble’s various members, but never at the expense of overall cohesion or musical authority.
On ‘Make It All Go Away’ from Brad Mehldau’s latest release, Finding Gabriel, the STR easily managed to pick its way through the multi-layered arrangement, with the digitised chorus and vocals spread wide to the left and right, the drums anchored dead centre, and the multi-faceted keyboards projected with spatial and temporal precision.
The dimensionality was so pronounced that it took on an almost surround sound-like stature. Again, the STR allowed a level of insight and attention to fine detail that greatly enhanced the listening experience, while retaining the thrust and cohesion of the music.
Cellist Edgar Moreau’s performance of Offenbach’s lovely Grand Concerto For Cello In G Major is engrossing. His command of the instrument is lyrical and intense, underpinned by impressive technical virtuosity.
The recording not only captures the solo cello’s depth of tone and texture, but also the agility and impact of Moreau’s playing, while the orchestra is presented with intimate restraint.
The STR’s treatment of the performance was immaculate, easily tracking the music’s dynamic swings and intricacies, while never losing sight of the cello’s starring role.
The Steve Gadd Band’s eponymous, Grammy Award-winning set is a slick, tautly structured and engaging album that’s also immaculately recorded. On the opening ‘I Know, But Tell Me Again’, the rollicking electric bass finds a perfect rapport with the upbeat drumwork and the sassy brass, while keyboards and guitar wait their turn to take centre stage.
There’s a lot happening on the busy, albeit expansive soundstage, and not surprisingly, Gadd’s drumwork is always at the forefront, providing an intricate rhythmic framework for the band’s other members.
The pace is unrelenting and energetic, but the STR always sounded up to the task, easily translating the shimmer and excitement of the music, while also ensuring an accessibility and lucidity that allowed the full scope of the performance to be appreciated and experienced.
THE BOTTOM LINE
In purely sonic terms, the STR Integrated is an adept, powerful and composed amplifier with a penchant for pace and passion. It’s not intimidated by large-scale productions, and delivers its sonic wares with an energetic enthusiasm that makes the music come alive.
That’s not to say that it isn’t able to capture the subtler nuances and details of the music. It’s able to pay as much attention to the finer elements of a performance as it does to the broader, bolder strokes – but it’s the cohesion and impetus of its delivery that stands out, together with wide-open staging.
There’s no doubt that the ARC system plays a pivotal role in the amplifier’s capabilities, and it would be pointless to use the amp without taking advantage of those benefits. Adding to ARC’s appeal is its bass management feature, which does a compelling job of integrating subwoofer delivery into the overall performance.
In that sense, this is probably not an amp for purists, who will baulk at the notion of digitising incoming analogue signals – although direct comparison will leave no doubt as to the musical benefits.
Add smooth tonality, plenty of inputs, superior subwoofer management and an overall sense of musical authenticity to the equation – all in a handy single-box form factor – and you have an enticing alternative to conventional high-end amplifier solutions.
Power output (20 Hz – 20 kHz, <1% THD): 2x 200 watts (8 ohms), 2x 400 watts (4 ohms)
Frequency response: 10 Hz – 80 kHz (+0, -0,1 dB)
Signal-to-noise ratio: 120 dB (<0,1% THD)
Digital inputs: 1x AES/EBU, 1x asynchronous USB, 2x RCA coaxial, 2x Toslink optical
Analogue inputs: 1x balanced stereo XLR, 4x stereo RCA, MM/MC phono stage
Outputs: 1x line-level stereo RCA, 1x variable-level stereo RCA, 2x subwoofer out RCA
Connectivity: 802.11 Wi-Fi, Ethernet, RS232 serial port
Dimensions (HxWxD): 172 x 432 x 445 mm)
Weight: 18 kg
Lumin D1/L1 network player/server
Marantz SA-KI Pearl Lite CD/SACD player
Primare PRE32 pre-amp
Parasound Halo A21 power amp
KEF LS50 speakers
Atlantic Technology subwoofer
Reese Wynans and Friends – Sweet Release (J&R Adventures)
Brad Mehldau – Finding Gabriel (Nonesuch)
Offenbach – Grand Concerto For Cello In G Major – Moreau/Merlin/Les Forces Majeures (Erato)
Steve Gadd Band – Steve Gadd Band (BFM Jazz)