Anthem Electronics STR D/A integrated amplifier

Stop me if I've said this before (okay, I have): There's much to be said for integrated amplifiers. While separates have long dominated high-end audio, an increasing number of integrated products not only bundle a preamp and power amp, but sometimes add digital inputs of various flavors, phono stages, bass and treble controls (long on life support in audiophile gear), and more.

It's the "more" that interests me—specifically, the access to equalization that can compensate, at least to some degree, for the inevitable problems created by any listening room of domestic size, particularly in the region below 300–500Hz. The Marantz AV8802a surround processor I use for much of my listening, including home-theater duties for our sister publication Sound & Vision, includes the Audyssey suite of EQ functions, although I don't use it. (The version of Audyssey built into the AV8802A equalizes either the entire audioband or none of it; the version of Audyssey used in the AV8802A's replacement, the AV8805, is more flexible).

As I've also often said, a typical review can tell you only how a speaker's bass sounds in the reviewer's room, not in your room. Yes, you can sometimes move the speakers and/or listening seats around and get better results—but the sound is still likely to be compromised, and domestic considerations often limit the options for speaker positions. In my room, apart from minor tweaks, the speaker and seating positions are constrained by the need for the speakers to complement a video screen for my work for Sound & Vision (though that can screen can be rolled up when music alone is on the menu).

In a typical audio system, therefore, we can often do little about the room's effect on the bass range. The frequency below which the room's contributions dominate the sound, called the Schroeder frequency, varies with the room. But unless your room is the size of a ballroom or concert hall, apart from your speakers' low-end limit, much of the quality of what you hear below 200Hz will be a product of the space you're listening in.

This can be treated with equalization, though the usual objections to EQ can't be totally ignored. EQ's effects are usually optimal only at or near the main listening seat or sweet spot—and elsewhere in the room, they might even make the sound worse than it is without EQ, though that can also be true of a non-equalized system. The insertion of extra circuitry in the chain might also adversely affect the sound. Some bass dips are virtually infinite—sonic black holes that EQ can't correct (though if narrow enough, they might well be inaudible). And the only practical way to perform the type of equalization I'm talking about is digitally, which to many audiophiles remains anathema.

Of course, well-equalized sound that's restricted to a single sweet spot isn't a problem for the lone audiophile who almost always sits in that spot. And objections to greater circuit complexity would apply only if any audible degradation outweighs the benefits. The fact that such EQ will require that any pure analog input signal be converted to digital for processing is just another campaign in the war of digital vs analog, which audiophiles began fighting in the late 1970s and which shows no sign of tapering off. Still, many products that include the type of digital EQ discussed here include an analog bypass for listeners who are alarmed at having their analog sources chopped up into bits.

The objections to the sonic degradations caused by added circuitry and complexity are somewhat mitigated when the EQ software is built into an integrated amp or preamp whose designer has control, rather than being done by an outboard device that might require external connections and additional A/D and/or D/A conversions. Classé's Sigma 2200i integrated amplifier, which I reviewed in April 2017, included a flexible range of parametric equalization, but its proper use required a user or dealer/installer with measuring tools and skills. The Anthem Room Correction (ARC) included in the Anthem STR integrated amplifier reviewed here is far easier to use, though getting it up and running does require some basic computer skills.

The Anthem STR ($4499) is available in all black or all silver. At 40 lb, it's moderately light and cool-running for a class-AB amplifier specified to output 200Wpc into 8 ohms, 400Wpc into 4 ohms, or 550Wpc (!) into 2 ohms across the entire audioband at less than 1% total harmonic distortion (THD).

The STR's power-amp stage is built around a single large, toroidal transformer, with oversize filter capacitors and load-monitoring circuitry for optimal performance. Its 2-ohm rating should allow the STR to work without breaking a sweat with virtually any modern speaker, some of which have impedances that can dip that low—or even lower—in at least a narrow part of their frequency range.

Apart from ARC, the Anthem STR offers more than the usual complement of features for an integrated. There are five analog inputs (four sets unbalanced, one set balanced); digital conversion and processing can be bypassed with each of them. The six digital inputs include two TosLink optical, two coaxial, and one AES/EBU, all of which support inputs of up to 24-bit/192kHz. An asynchronous USB Type B digital input accepts PCM up to 32/384, and DSD at 2.8 or 5.6MHz. All internal digital processing is performed in PCM at 32/192, so all digital inputs are converted to that resolution, including DSD and, if desired, the analog inputs.


There's also a pair of unbalanced, fixed-level RCA preamp outputs for connection to a headphone amp (the STR has no headphone output, a curious omission in today's market), plus separate, variable-level, unbalanced preamp outputs, in the unlikely event that you choose to later add an outboard amp. (Anthem also offers the identically featured STR preamplifier, for $3999; the onboard amps in the STR integrated are either a bargain at $500, or the preamp is a bit overpriced!) There are also dual subwoofer outputs (I didn't test them), configurable for mono or stereo. Should you go the EQ route, ARC will also correct the response of any subwoofer hooked up to your system, including separate EQ for stereo subs.

The STR has two phono inputs, one each for moving-magnet and moving-coil cartridges. My experience with the current state of vinyl playback is limited, so any test by me of these inputs' sound would be more a comment on the sounds of some ancient cartridges than on the STR itself. So I didn't listen to the phono inputs; John Atkinson assesses their performance in his "Measurements" sidebar.

There's an Ethernet port for configuring ARC (the STR itself is not WiFi-capable); alternatively, a mini USB B port can be used to set up ARC via a PC configured with the downloadable ARC software. A USB Type A port is for factory use only. An RS-232 input, a remote IR input, a 12V trigger, a single pair of high-quality L/R speaker terminals, and the ubiquitous IEC port for the detachable power cord fill out the spacious rear panel, which isn't nearly as crowded as this description makes it sound. For those accustomed to the connections on a surround processor, it's downright sparse.

The large display on the STR's front panel shows the volume setting in numerals large enough to be read from across the room. When Info is selected, additional information appears: the operating input, ARC status (on or off), source resolution, and whether the output is in stereo or mono. The illumination level of these readings can be dimmed or turned off; in the latter case they still appear briefly, when an adjustment is made, then disappear. I left the window on all the time—I like to keep track of where I am during a review—but Anthem has you covered if you're concerned about any effect a lit display might have on the sound (I'm not, and heard none.)

A single large knob to the right of the display can be used to adjust the volume in steps of 0.5dB, or to navigate the setup menus. There are also buttons for Power, Mute, and additional setup actions: Menu/Select, Previous, and Next. I rarely used any of the front-panel controls, preferring Anthem's small, wireless, IR remote-control handset, which can be used to perform the identical functions. But some things, such as giving the inputs custom names, might be easier to do via the front panel.

One feature I'd someday like to see on an integrated amp with digital processing (I know of none that currently offers it, including the STR) is a digital output that provides a digital conversion of any of the amp's analog inputs at a high resolution; say, 24/192. This would be incredibly useful for any audiophile wanting to rip LPs to a server, though I suspect the very idea might make some analog-forever fans' heads explode.

Setup: Basic
The STR can be adjusted in a number of ways, with or without EQ. You can apply high- and low-pass filters for the main speaker and subwoofer(s) outputs at any frequency from 20 to 160Hz, and adjust the sub's polarity and level, and the listening position. The high- and low-pass filters can be defeated if you want to drive the main speakers full-range with a sub, then set the sub's low-pass frequency with its own, onboard low-pass filter (which most subs have). Other selectable features include balance, bass, and treble controls, and a rumble filter.

You can choose to convert the analog inputs to digital 32/192, or turn the conversion off and pass the analog signal along to the amp section with no digital conversion. But this will bypass ARC for the analog input selected, as well as all features described above that are also dependent on digital processing: bass and treble controls, rumble filter, and all subwoofer filters and adjustments. The subwoofer outputs will remain active, both of them carrying full-range mono; you'll then have to use the subwoofer's own low-pass filter.

Anthem Electronics
205 Annagem Boulevard
Mississauga, Ontario L5T 2V1
(905) 696-2868

Bogolu Haranath's picture

Considering all the different things it can do, the Anthem integrated is one of the "best bang for the buck" products ............

hifiluver's picture

for the big $$$ it better perform. Still I liked the brand better when it produced simple straightforward and more affordable products like the Integrated 225.

ppgr's picture

The average is not smoother, it's only averaged :)

Manimaldoug's picture

That is one handsome amp. Beautiful

Bogolu Haranath's picture

"Get outta of my dreams, get into my car" :-) ............

volvic's picture

Always wanted a pair of these great speakers. A few years ago someone was selling a pair with every replaceable woofer and tweeter as spares. Should have jumped on the chance. Nice to see Mr. Norton still using his.

stasis05's picture

This was a great review, but I really wish the reviewer had been given more opportunities to explore the features--no opinions on either of the phono inputs, no trying it out with even more high end speakers to see how it compares to integrated amps two or three times its price, etc. Seems like the reviewer was forced to review it based on a stereotype of Anthem as a home AV brand first, audiophile-brand second. I would have loved to see how it stacked up against a Mark Levinson or Pass Labs Integrated to see if it could hold its own.

funambulistic's picture

I would also like to see how these integrated amps, in this relative price range, that have bass management/room correction (Anthem, Parasound, Outlaw, Classe) perform in a 2.1 configuration. I know a lot of stereo only folks that round out their systems with a subwoofer or two (including myself). I believe the only recent review of an integrated (receiver, actually) that incorporated subwoofers was that of the Arcam FMJ SR250, written by Mr. Rubinson

audiodoctornj's picture

Dear Mr. Norton, thank you for your insightful review of the STR. I do believe you summed up the STR nicely. We feel that the Anthem STR is an excellent piece for the money with a very clean detailed presentation even without using ARC.

When you combine the STR's excellent power amplifier stage, a state of the art Room Correction system, a very capable dac stage, and a phono stage for a very reasonable $4,500.00 the STR should be on anyone's list to check out.

Howerver, the real shocker is the more expensive STR series amplifer and preamp/dac at $10k. The STR amplifier and preamp/dac just has an even more liquid overall presenation, while improving upon all aspects of the integrated amplifier.

You have to spend considerably more money than the STR separates to really move into higher quality sound, so the gentleman who asked about other brands, the new Anthem STR series products are really good sounding and are very competitive with any of the major audiophile brands.

Dave Lalin, owner, Audio Doctor NJ

NPRlistner's picture

I am trying to decide between these two to run a pair of 4 ohm speakers at 90db sensitivity. I use a Lumin D2 for streaming. What are your thoughts Dave?