Anthem STR Preamplifier and STR Power Amplifier

Accuracy, Authority, Adaptability

Equipment report
Solid-state power amplifiers,
Solid-state preamplifiers
Anthem STR Preamplifier and STR Power Amplifier

Right out of their respective boxes, the STR components impressed with the immediacy, detail, and authority of their presentation with all kinds of music. First of all—and I can’t say this is a surprise, given that I’ve used the Anthem D2 for what amounts to an eternity in audiophile time—the new Genesis software works extremely well to neutralize problematic room effects. This is easy to assess, as ARC can easily be turned on and off in the preamp’s “Preferences” menu, the sonic quality transforming from good to superior with the press of a button on the remote. This was readily heard on my frequent reference for well-recorded pop/rock, Kevyn Lettau’s Songs of the Police, a JVC XRCD24 remastering of an analog original. On this disc “Every Breath You Take” is rendered as a down-tempo, gospel-inflected torch song. With ARC activated, the richly arranged backup vocals were more intelligible, and the scorching alto sax solos were less stressed-sounding at life-like volume levels. Predictably, it was the low frequencies that benefited most from DSP correction. Without equalization, the bass had something of the wooly character experienced with the jukebox at the corner bar. With ARC on, electric bass and kick drum gained considerably in clarity and slam. 

My practice over the last eight years has been to use DSP room correction only as far up on the frequency spectrum as is necessary to smooth out major anomalies seen on the room EQ curves generated by the Anthem program—the top limit being about 700Hz with the STR gear. But turning the setting considerably higher, to 5kHz (the default), to 10kHz, or even to 20kHz didn’t meaningfully compromise the transparency of the equalization process. 

Many critical listeners will conclude that the goal shouldn’t be to achieve an absolutely flat room response. In my room, there’s a rise of a few dB occurring at 5 to10kHz with the Magicos that can be largely eliminated with some knowing manipulation by ARC. But doing so resulted in a loss of “air” and excitement with a favorite orchestral selection, the opening movement of the Shostakovich Symphony No. 15 with the great Royal Concertgebouw Orchestra led by Bernard Haitink. There really aren’t many domestic living spaces that can’t be helped by well-executed DSP room correction but, obviously, you don’t want to remove the life from a recording. The baby with the bath water and all that.

I tried out the various digital inputs—all performed quite well—but gave particular attention to the USB interface, needed to support DSD codecs. What I found was that the DAC section of the STR preamplifier will not accept “native” DSD (as does the T+A DAC-8-DSD, which has a dedicated one-bit converter), but instead employs “DoP”—DSD wrapped in a PCM container—which Anthem feels involves no sonic compromise as it doesn’t involve actual format conversion. (See sidebar.) 

Are we just bearing witness to a marketing war between those brands with DACs that can handle native DSD and those that use DoP to manage DSD files? I can’t say. For what it’s worth, I preferred, by a slight margin, JRiver’s transcoding of a DSF file to 32-bit/48kHz PCM to the 2.8MHz DoP version sent over the same USB connection to the STR in terms of spaciousness and textural nuance. 

Neither option was quite as good as playing native DSD via USB from the Baetis to the T+A—there was a more lifelike gradation of dynamics and sense of occasion heard with the Shostakovich. But, honestly, these were small differences. Likewise, when it came to PCM digital transmitted via a coaxial, optical, or AES/EBU connection, the Anthem gear got startlingly close to the German DAC, which costs $450 more than the complete Anthem preamp.

Given the digital legerdemain that this preamplifier is capable of, one might be inclined to think that the phonostage was merely an afterthought. But Anthem offers six equalization curves other than RIAA as well as a user-defined curve, possibly appropriate for older records, which sounds like it is taking vinyl playback pretty seriously. Vinyl aficionados may still insist on an outboard phonostage that allows for cartridge-loading alternatives other than 47k ohms (for moving-magnet and high-output moving-coil cartridges) and 100 ohms (for low-output mc’s), and even with my modest LP playback rig I found that records sounded better when an Audio Research PH2 phono preamplifier was inserted into the chain. Most casual vinyl consumers will probably find the Anthem’s performance more than adequate. I tried sending the PH2’s output to both an upsampling digital input and to an analog pass-through alternative. The former seemed a little synthetic-sounding, so I stuck with the bypass option and did without room correction for vinyl playback.

The amplifier impressed as well when compared head-to-head with a far pricier pair of Pass XA60.8 monoblocks. Spatiality and low-end weight were excellent, and there certainly was no question of the STR running out of steam with the most dynamic recordings, like Gordon Goodwin’s Big Phat Band’s Act Your Age. With the grip that the Anthem amp applied to the Magico S3 Mk2’s woofers, I was happy to forgo the subwoofer and avoid any possibility of room overload when the big band album was played at decidedly enthusiastic levels.

Comparisons to other pieces of audio gear are one thing; comparisons to real musical experiences are another. Massed voices did quite well—the dozen singers of Stile Antico singing “Never Weather-Beaten Sail” demonstrated sibilants and final consonants that were naturally connected to the main body of the note they belonged to. The scaling of instruments of different sizes was realistic, as with violin and Steinway grand on the nonpareil 1987 Wilson Audio Specialties recording of the Brahms Violin Sonata in G major. Exactly right, as well, was the tonality of David Abel’s fiddle on that album, readily identifiable as a Guarnerius and not a Strad. And Abel is standing precisely where the late David A. Wilson said he should be: “The sonic image of the violin should originate just to the right of the inside edge of the left speaker.” And it did.

Which leads to one last observation about the STR preamplifier and amplifier combination that occurred to me as I packed them up for their next journey. 

The two components were in my system from mid-March to mid-May, which happens to be the busiest time every year for me to take in classical concerts. In that span, I saw two operas, and attended two orchestral concerts, two chamber music recitals, plus a couple of piano performances. Normally, I have a hard time listening to recordings for a period of time after enjoying the live experience, maybe for a day or so. Yes, it’s probably setting an unnecessarily high bar but I guess I’m looking for the sort of emotional connection I get from flesh-and-blood musicians in an acoustically favorable venue when I sit down in front of my audio system. I got more than a little of that when listening to canned music with Anthem’s STR electronics—it seemed that I wasn’t nearly as refractory to the appeal of my favorite recordings. That’s a distinction, for sure.

Specs & Pricing

STR Preamplifier
Type: Two-channel solid-state preamplifier with DAC
Analog inputs: Two balanced, both configurable for home-theater bypass; four RCA, two configurable for home-theater bypass
Digital inputs: Coaxial (2), optical (2), AES/EBU, USB
Phono inputs: Low-output moving-coil (100 ohm impedance, 61dB gain); high-output moving-coil/moving-magnet (47k ohms impedance, 41dB gain)
Formats supported: Asynchronous USB input: 32-bit/192kHz PCM and DSD 2.8/5.6MHz; coaxial, optical, and AES/EBU inputs up to 192kHz PCM
Outputs: Balanced right and left, two subs; RCA right and left, line-level out, two subs
Dimensions: 17" x 4" x 15"
Weight: 16.8 lbs.
Price: $3999 

STR Amplifier
Type: Solid-state Class AB stereo amplifier
Output power: 400Wpc into 8 ohms, 600Wpc into 4 ohms, 800Wpc into 2 ohms
Inputs: One pair RCA, one pair XLR
Input impedance: 10k ohms (RCA); 15k ohms (XLR)
Outputs: One pair of loudspeaker binding posts
Dimensions: 7" x 17" x 18.5"
Weight: 60 lbs.
Price: $5999

205 Annagem Blvd.
Mississauga, ON L5T 2V1

Native DSD or DoP: Does It Matter? 

The question of “native” DSD vs. DoP is a kind of religious war within a religious war. At least for some more dogmatic audiophiles, the first consideration is if DSD-encoded files sound better than PCM files of similar resolution—or vice versa. Generally, direct comparisons aren’t possible, as DSD recordings must be mixed, edited, and mastered in the PCM realm. There really is no such a thing as a “pure” DSD recording available commercially, other than analog material transferred, untouched, to DSD and the rare “direct-to-DSD” project that don’t undergo editing. But although there are well-recognized problems with DSD— quantization noise rises sharply above 25kHz and complex noise-shaping algorithms and filters are needed to assure that this phenomenon doesn’t translate into audible unpleasantness—plenty of respected recording professionals hear musically meaningful differences between PCM and DSD, especially when it comes to the low-level information that’s heard as “spaciousness,” and choose to work with the latter. Others feel they get better dynamics, more detail, and a less fatiguing listening experience with DSD.

If you are a DSD partisan, is there an advantage to listening to native DSD as opposed to the DSD-over-PCM (or DoP) variant? For both, getting a DSD file from a computer to a DAC via a USB interface requires “packetizing” of the data stream. In the case of native DSD, the stream is broken up into relatively big pieces, 8192 bits in length, which is the size of a USB packet. At the recovery end—that is, at the DAC—these chunks are reassembled into a coherent digital signal. With DoP, the DSD stream is diced into much smaller fragments of just 24 bits. With the addition of some extra non-musical bits, each packet achieves a length of 32 bits, the standard size of a data sample that the DAC can recognize as PCM content. A bunch of these 32-bit particles are then combined into 8192-bit USB packets and, ultimately, the complete data stream is reconstituted. All the non-musical packetizing bits, of course, must be removed from the DSD information.

This is where the perspective of different manufacturers can diverge. To John Bagby, a co-owner of the Anthem, Paradigm, and MartinLogan brands, the DoP process works perfectly. His succinct conclusion regarding audible differences between native DSD and DoP: “Our position is that there is no difference with a bit-for-bit copy packaged in PCM for DoP.” Obviously, those who design their DACs to receive native DSD have a different view. Lothar Wiemann, Head of Development for T+A, notes “the process for DoP is more complex with more opportunities for data loss, clocking errors, or other compromises as opposed to native DSD streaming. Further, because of the extra bits that have been added and because of the structure of the PCM format, DoP has a big data overhead and is much less efficient.”

If you are a true believer, the NativeDSD Music website offers a spreadsheet listing close to 600 DSD DACs and players, identifying which ones will accept native DSD, as opposed to “just” DoP. From my standpoint, this variable isn’t worth losing sleep over as so many other aspects of the playback system and, of course, the recording itself can trump the importance of the file format and/or the method employed to get the digital signal from player to DAC. The capacity to play native DSD should not be the overriding factor in a purchase decision regarding a preamp, processor, or DAC.