Anthem STR Integrated Amplifier Review

Sometimes bigger is simply better, says Jay Garrett of this talented Canadian integrated amplifier...
Anthem
STR Integrated Amplifier
£4,500
Canadian brand Anthem has long been famous for its well-respected AV preamplifiers, processors and receivers. In 2017 however, the Ontario-based business sent its new two-channel products across the Atlantic, launching its STR range. The new preamp, power amplifier and integrated were the company's first stereo products since 2009's 225 integrated. Anthem's Product Manager Blake Alty told me that despite the eight-year hiatus, "the design starts the minute the previous generation is released", adding that "the most intensive portion of the new STR integrated amplifier's design took two years."
Although the Anthem STR integrated ticks all the boxes one would expect a product costing £4,500 to, it also boasts some special sauce in the form of the company's proprietary Anthem Room Correction software in its latest Genesis guise. This has been praised in audio-visual circles and, as Blake told me, "Anthem strives to incorporate everything appropriate to a product, and ARC is no different." So here we have it in a stereo component, and the question is how well does it work in this context. Is it a valuable addition to those running stereo systems, as opposed to multichannel?
ARC can be accessed via an iOS and Android app or, to get the full benefit, from a PC or Mac. The software lets you measure the effect that your listening environment has on your loudspeakers' presentation. Measurements are made using your device's mic, a supplied USB mic or a calibrated microphone and stand. The results are marginally different, with the calibrated mic producing more accurate measurements. From here on in, the software creates corrective filters which are then uploaded via your home network to the amplifier.
HEAVY METAL
The STR integrated is a beast, measuring 432x172x445mm (WxHxD) and weighing 18kg. However, within its silver-coloured case (black is also available), there is a colossal 'low stray flux' toroidal transformer, as well as a hefty class-AB power amplifier. The amp's output is rated at 2x200 watts into 8 ohms, doubling to 400W per side into 4 ohms, and then stretching to 550 watts into 2 ohms. Even the most insensitive and/or demanding loudspeakers should fear it!
Thanks to the amp's height, it has plenty of real estate to support a sizeable TFT-LCD screen which displays volume level, source and signal format info, as well as ARC status. It also makes using the speaker set-up and input configuration menus a breeze, especially when making selections via the sturdy aluminium-hewn remote control. Alternatively, you can use the machined aluminium control buttons and oversized volume dial whose primary duty is to adjust the loudness in 0.5dB increments.
Around the back, you'll find a pair each of coaxial and optical ports and an AES/EBU input. Additionally, there is an asynchronous USB input that supports stereo PCM up to 32-bit/384 kHz and DSD up to 5.6MHz. Mac users get plug-and-play DAC connectivity, while Windows types need the driver from Anthem's website. There are ports for Trigger in/out, an RS232 and a couple of USB sockets for updates; finally, there's an Ethernet port purely for ARC configuration and IP control.
Analogue connections include four pairs of RCA inputs, a set of balanced XLR and separate moving magnet and moving coil phono inputs. Interestingly, all can be configured to bypass the internal digital processing. Naturally, doing so means bass management and room-correction for those inputs won't be applied. That said, the STR's flexibility allows you to have your cake and eat it. For example, you can configure the same physical input with and without digital processing for quick comparisons. Lastly, there's a pair of subwoofer output jacks for left and right stereo pairing. However, either one of these outputs can be used for a single sub.
GETTING GOING
I spent my early evaluation period using the STR integrated like a regular amplifier, then used the ARC app on my phone with the standard USB microphone fitted to take the necessary measurements. This resulted in tamed bass frequencies. Although it did remove some of the excitement and fun element of the amp's presentation, it also mitigated any bass boom. Finally, I hooked up the calibrated and serial-numbered microphone to my laptop.
Using the supplied mic stand, I again took measurements guided by the onscreen wizard. As the stand remained at a constant height, this method undoubtedly gave more consistent measurements. The result was a rich low-end that was more dialled in and appropriate for my space. Additionally, the midband and highs now sat better in the mix.
The Anthem STR is a geek's dream, to be sure. As well as ARC's settings and graphs, its set-up menu offers a wide range of options. Firstly, you can create various speaker profiles (Stereo Plus Subwoofer, Stereo No Subwoofer, and so on), which is equally handy if you have a variety of speakers to hand, as you can add profiles for those too. Also, inputs can be renamed and linked to a specific speaker profile, ARC status and playback mode.
Then there are the aforementioned phono input options which let you turn analogue conversion on or off. When switched on, the incoming signals are sampled at 32-bit/192kHz. Furthermore, in addition to the standard RIAA EQ curve, you are offered Capitol, Columbia or London LP variants, as well as being able to set the rumble filter frequency in 1Hz steps. All of this can keep a menu-delver such as myself occupied for the best part of a day!
SOUND QUALITY
Is the Anthem STR integrated all gear and no idea? Heck no! Even before engaging its ARC skills, the Canadian behemoth proved to be a highly competent performer – and far more nimble than I had something this gutsy pegged for. Nighthawk (Vampire Blues) from the remastered 1978 Whitesnake album Trouble is a frenetic blues cut that's busy with harmonised guitars and the incredible rhythm section of Dave Dowle and Neil Murray. The STR lapped it all up and made it incredibly involving – timing was right on point, and the punch through my reference Marten Duke 2 speakers was tantamount to listening to the track played live in a well-sorted backroom venue.
There was remarkable separation and imaging with Tash Sultana's Synergy filling the space with airy ease. However, my room started to present some unwelcome boomy bass when I helped myself to some more of the STR's generous power.
Dialling in ARC via the mobile app adjusted the amp's output, giving a more mid-forward presentation which gave the acoustic guitar and vocals – especially in Puscifer's Momma Sed – a tangible, in-the-room feel.
However, I immediately missed the lowest ranges, so it was time to roll out the calibrated mic and spend ten minutes sorting the full-fat ARC Genesis experience. This resulted in tight yet extended bass plus a notable increase in definition and body across the board.
Where tighter bass may be ARC's most prominent contribution, there was an increase in midrange clarity and better balance throughout the frequency range. The added benefit here was that speed also improved. As Leonidas Kavakos's incredible rendition of Op. 1, MS 25: No. 5 in A Minor: Agitato from Paganini's 24 Caprices for Solo Violin blazed through my speakers, there seemed to be a direct conduit between Kavakos and myself. Low mids had weight, the upper register was crisp, and the double stops were rich in harmonics.
For all its technical wizardry then, the STR integrated has a full and natural presence that draws you further into the music. For instance, the ethereal piano in GoGo Penguin's Raven may be dressed in reverb, but the tone of the instrument was rendered beautifully full. The urgent drum patterns behind created an exciting contrast that the STR proved able to balance faultlessly.
Thanks to the Anthem's impressively flexible phono set-up, the STR integrated proved an excellent choice for vinyl fans too. Duran Duran's Come Undone sounded like a studio session in my living room, as the big amp's analogue-to-digital conversion and ARC painstakingly drew out the arrangement's component parts. The percussion was tight, and bass notes were defined and driving during Fleetwood Mac's Go Your Own Way. Any fears of losing transparency thanks to the ARC system fell by the wayside listening to David Bowie's Station to Station. Flicking between analogue bypass and digital conversion modes, I couldn't discern any tampering with Bowie's vocals or loss of instrumental realism. What was achieved with ARC engaged; however, were heightened dynamics, punch and control.
THE VERDICT
Anthem's STR integrated amplifier proved itself well up to the challenge of driving even the most demanding loudspeakers, and its vast reserves of power add a level of transparency to the listening experience that mitigates against compression and distortion. Such controlled power – allied to its fine phono stage, multiple inputs and great functionality – means it offers a lot of sound per Pound. The cherry on the cake is the ARC system, which some people – especially those living in adverse acoustic environments – will find it hard to be without. Do hear it if you possibly can.
For further information, head on over to Anthem.

Jay Garrett
StereoNET’s resident rock star, bass player, and gadget junkie. Jay heads up StereoNET as Editor for the United Kingdom and Europe regions. His passion for gadgets and Hi-Fi is second only to being a touring musician.
Posted in: Hi-Fi
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