Anthem STR Amp Review

NEW Anthem STR Integrated Amplifier Review

By Andrew Donald

Anthem, the Canadian hi-fi sister company to both MartinLogan and Paradigm, have just released an impressive new integrated amplifier, called the STR. It’s an entirely new architecture that elevates this new offering well above the amp that it replaces, the Integrated 225.

Integrating an advanced preamp with a high output stereo power amplifier, and adding advanced DAC (Digital-to-Analog Converter) functions, a Moving Magnet and Moving Coil phono stage and the mighty ARC (Anthem Room Correction) room calibration system into one chassis, the new Anthem STR certainly covers a lot of bases for its $5500.00. The fact that it offers all of this capability and also manages to sound terrific, it’s a relative bargain at that price!

The STR is designed, engineered and built by Anthem at Paradigm’s impressive facilities in Toronto, Canada, and as such Anthem has a tremendous amount of control over the design and manufacturing process to deliver the best finished product. In the early stages of the STR’s design, Anthem decided it was time for their sole integrated amplifier to move upmarket and it’s fair to say that they’ve accomplished their goal admirably

Description:

Upon unpacking it, the first thing noticed is its heft. At 40lbs, it’s no lightweight. Peering into the internals through the top venting also illustrates the care that went into the internal packaging. With a large toroidal power transformer taking the center position, each amplifier channel and their accompanying heatsink flanks it on either side. Behind the aluminium front panel sits four large capacitors (two for each channel) on their own isolated board. The preamp, DAC and phono preamp are on another isolated circuit board near the back of the chassis. The front panel is quite clean with a very prominent display on the left side of the faceplate. It’s bright and sharp with decent contrast when viewed straight on and offers plenty of information over the amp’s functions, with nice graphical icons to liven it up a bit.

The I/O offering is impressive for a stereo integrated amp. With one AES/EBU, one USB, two digital coax and two optical inputs for its built-in DAC; the analog section has a set of balanced XLR inputs and four sets of stereo single-ended RCA inputs. There are MM and MC stereo single-ended RCA inputs for the phono stage. The amount of analog outputs are truly luxurious, with single-ended RCA Left and Right, subwoofer Left and Right and line Left and Right outputs!

For firmware updates and control there is a USB-A, Mini USB, Ethernet, RS232 serial, and a 3.5mm 12V trigger Output and 3.5mm IR Input. There are also oversized insulated and non-conductive five-way binding posts for speaker connections free of any interference or ghosting.

The amplifier section of the new STR is a beast. With 200 watts per channel continuously into an 8ohm load, it can also “double down” when the speaker’s impedance halves, delivering 400 watts per channel continuously into 4ohms. It’s also 2ohm stable, continuously delivering a mighty 550 watts per channel! Now, that is serious power from an integrated amplifier.

The built-in digital-to-analog converter is no slouch either. Capable of accepting a hi-resolution digital bitstream up to 24bit/192kHz via its digital coax and optical inputs. It can also upsample non hi-res digital signals up to 24bit/192kHz! Set for the future, the STR can also accept a PCM signal up to 32-bit/384 kHz and a DSD 2.8 or 5.6 MHz digital bitstream through its sole asynchronous USB-B rear input.

Another feature that the vast majority of stereo amplifiers don’t offer is a way to equalize your system to the room it’s in. Anthem has extended their superb room correction system (ARC – Anthem Room Correction) that is built into every one of their surround receivers and surround processors, to the new STR. Instead of relying on an IC in the STR to do the calculations, ARC leverages the power of your PC running the ARC software. With an included tripod mounted microphone connected, ARC digitally compares a room’s acoustic signature to that of a reference.

It measures the response of each speaker relative to the space and eliminates the negative effects of obstacles in the room, adjusting response, correcting phase issues and the negative effects of problematic room reflections, resonances and standing waves caused by the shape of the room and the surfaces and obstacles in the room. It can even do separate EQ’s for two subwoofers in your system, which is perfect for audio systems with a stereo subwoofer configuration!

In practice ARC works extremely well and is very approachable and user friendly. It’s streamlined and easy for those that want that and extremely deep when you want it to be, allowing for a huge degree of customization. It’s a brilliant platform that allows for easy and intuitive experimentation with different speaker and listening positions, crossover, phase and level configurations in real-time while you’re in the ARC software. It’s a calibration system that caters to every level of user.

Installation & Listening:

After unpacking the amplifier (the STR in black looks superb!) and connecting it to one of our reference systems comprised of Paradigm’s Persona 5F loudspeakers, a Bluesound Node 2 network music streamer (for accessing lossless CD quality tracks, as well as MQA, from our Tidal Hi-Fi subscription) and Torus RM20 line conditioner, it was set up and gently broken-in for several days. Afterwards we had very lengthy listening sessions and were quite impressed.

The STR’s damping factor is immediately apparent with fantastic control of driver motion that shows off the 5F’s great transient response. The amp’s authoritative bass is very good as well. It really grabbed the 5F’s from the collar and showed them who’s boss! Midrange warmth and smoothness, with a slightly etched character to high frequency detail characterizes the STR well and the soundstage was wonderfully deep and delineated, accentuating the 5F’s already great transparency and imaging capability.

The new STR amp is a power house that can drive a very broad range of speakers. It also has the control and finesse to create a truly enjoyable listening experience that keeps inviting you back for more.