Recommended Components

A

Anthem STR: $4499 $$$
Anthem's solid-state STR integrated amp offers 200Wpc (into 8 ohms) of class-AB power, along with seven analog inputs—one balanced, four single-ended, and two phono (one MM, one MC). It also offers a 32-bit/192kHz D/A processor with six digital inputs—four S/PDIF (two RCA, two TosLink), one AES/EBU (XLR), and one USB. A subwoofer output is provided, but, curiously, there's no headphone output. Of interest to users with problematic listening rooms is the STR's built-in Anthem Room Correction (ARC) processor: using the supplied microphone, ARC can be set up using a PC that's been configured with the appropriate (downloadable) software and connected to the Anthem's miniUSB or Ethernet jack. (The latter has no other function: the STR is not WiFi capable.) Even before setting up and trying ARC, TJN enjoyed the Anthem STR for sounding, with one recording in particular, "punchy and likely true to the source, with excellent detail and an open midrange." With ARC engaged, TJN heard differences that "ranged from subtle to striking . . . and were only rarely inconsequential." Benefits included a "cleaned up" double-bass sound on one CD, greater upper-bass precision in the sounds of massed voices on another. His conclusion: "a watershed product worth serious consideration." Writing of his experiences in measuring the Anthem STR, JA called it "a well-engineered amplifier offering high powers and respectable measured performance." (Vol.41 No.7 WWW)

ASR Emitter II Exclusive: $27,000
The four-box, solid-state Emitter II Exclusive—five boxes if you count the chunky, Corian-encased remote handset—weighs over 300 lb total, largely (haw) for the number of outsize frame-style transformers it uses. The separate boxes include the amp itself—which is over 22" wide—plus two outboard power supplies and one outboard battery power supply, plus automated charging system for the amp's input circuitry. And that handset. Technical highlights of the 250Wpc (into 8 ohms), class-AB Emitter II Exclusive include input and output sections whose every active device is mechanically isolated, a variable-gain volume-control system actuated by a rotary encoder, and internal switches for tailoring most performance variables to the user's system; nontechnical highlights include a physical design unlike that of any other audio product, elements of which AD found "strangely beautiful," plus documentation, ergonomics, and a gestalt that had AD reaching for the L-word (as in love, not inductance). Through his DeVore Fidelity Orangutan O/93s, the ASR produced a grand sense of scale, a very good sense of flesh and blood, and stirring musicality; from AD's Quad ESLs the ASR teased momentum, clarity, touch, impact, electronic gunklessness, and the snappiest bass he's ever heard from those speakers. Art concluded that the ASR is "a very complex product that somehow manages to sound very simple." A great, unique integrated amplifier, and a must-hear for ESL owners. (Vol.41 No.8 WWW)

Ayre Acoustics AX-5 Twenty: $12,950 ★
In 2013, AD described the original Ayre AX-5—a $9950 integrated amplifier built around a recently rediscovered configuration of bipolar transistors known as the "diamond" circuit—as "one of the three best, most musical, most human-sounding solid-state amps I've ever heard." Then, in 2015, Ayre debuted a new version, the AX-5 Twenty—a nod to the company's 20th anniversary—promising even better sound. The AX-5 Twenty is built into the same foursquare aluminum case as the AX-5, and is controlled by the same performance-optimizing Variable Gain Transconductance (VGT) volume-control system—but the Twenty incorporates Ayre's new Double Diamond output, claimed to run cooler (which AD verified) and to offer slightly more power (though the 125Wpc rating remains). This time out, AD got a little pissy about Ayre's user manual and the amp's "pointlessly complex" setup procedure, but was otherwise smitten: He delighted in a sound that was "slightly sweeter" than the original AX-5's. Stringed instruments, he said, were "reproduced with color, body, scale, melodic and rhythmic drive, and believable spatial presence." AD concluded that "the AX-5 Twenty is inarguably . . . more compelling than its predecessor." Although he raised an eyebrow at the 30% ($3000) price increase over the original, AD commended Ayre for allowing AX-5 owners to have their amps upgraded to Twenty status for the same price. (Vol.38 No.8 WWW)

Ayre Acoustics EX-8: $5950–$7850
Although Ayre's new EX-8 integrated amplifier is available as an analog-only base unit for $5990, the company makes increasingly flexible, increasingly costly versions, all the way up to the fully loaded EX-8 Integrated Hub that JA wrote about in the February 2019 Stereophile. This combines an onboard D/A processor with S/PDIF, AES/EBU, and USB inputs, an Ethernet port, and Roon readiness. The 100Wpc output section retains Ayre's feedback-free Diamond circuit—here, the output devices are mounted directly to the bottom of the amp's aluminum enclosure—but disposes with the company's Variable-Gain Transconductance (VGT) volume system in favor of a conventional albeit high-quality Alps pot. As JA discovered in his listening tests, the Ayre allowed singing voices a fine sense of presence, consistently projecting them forward on the soundstage—though he judged that "too much of a good thing" with overcooked recordings. Switching hats to his role as measurer-in-chief, JA noted the EX-8's low-for-an-integrated gain and a harmonic distortion character that led him to wonder if using the chassis as a heatsink prevented the amp from being biased too near the class-A end of things. That said, the EX-8's measured performance was "generally excellent" in both the analog and digital domains. JA's verdict: "a high-end contender at a competitive price." (Vol.42 Nos. 2 & 4 WWW)

Bel Canto Black ACI 600: $25,000
No mere integrated amplifier—designer John Stronczer claims that his product "diverges from traditional architectures"—the Bel Canto Black ACI 600 is, in essence, the combination of a 24-bit/192kHz D/A converter with a 300Wpc class-D amplifier, the latter constructed with NCore modules. Also featured are a phono stage with MM and MC inputs, digital bass-management controls, circuitry for unfolding MQA files, and Seek, an iOS-based app for streaming music from Tidal—although, at the time of his review, JVS described Seek's instructions as inadequate. Happily, the sound was anything but: "Once fully warmed up, the Black ACI 600 shattered all notions of class-D sounding colorless and uninviting," wrote JVS, though "treble extension was a bit toned-down from what I'm accustomed to." His conclusion: "That this single box can do so much so well . . . should earn it pride of place in many a system." Writing from his test bench, JA noted the Bel Canto's difficulties with 384kHz files, but found it exceeded its power rating into 8 ohms, fell a bit short into 4 ohms, and evinced "respectable measured performance" overall. (Vol.41 No.4 WWW)

Bel Canto Design Black amplification system: $55,000 ★
Tempting though such a classification may be, the Bel Canto Black is more than just an integrated amplifier. This three-box system comprises a sort-of preamplifier (the ASC1) and a pair of sort-of monoblock amplifiers (the MPS1), the latter operating in class-D, for 300Wpc into 8 ohms or 1200Wpc into 2 ohms. The Ethernet-ready ASC1 can be controlled with an iPhone app; it provides a brace of digital inputs, and via ST-optical connections feeds the MPS1s digital signals at their native resolutions, up to 24-bit/192kHz and DSD64. The ASC1's single pair of analog inputs (RCA) address an internal 24/192 DAC: Everything that goes through the ASC1 does so as a digital stream, eligible for tailoring by a variety of user-selectable digital filters. (The MPS1s also offer analog inputs.) In his listening tests, MF found the Bel Canto Black to offer "the most compelling digital sound yet," and to embody the best-yet implementation of class-D technology: "[H]ere, finally, is a class-D product that, though sounding definitely different from the older technologies, makes a strong case for equality." JA declared that he was "very impressed by the Bel Canto Black, especially with its behavior as a D/A converter that is effectively capable of driving loudspeakers." From his own listening tests, described in a Follow-Up, JA noted the Black's ability to present spatial and sonic detail. Comparing the Bel Canto to the recently reviewed Ayre Acoustics KX-R Twenty preamp and MX-R Twenty mono amplifiers, JA wrote: "If the Ayre system was more simpatico with the heart, the Bel Canto Black appealed more to the head." (Vol.38 Nos. 7 & 10 WWW)

Cambridge Audio Edge A: $5000
Created for Cambridge Audio's 50th anniversary, the Edge A charts newish territory: a combination D/A processor and integrated amplifier designed and built to perfectionist standards. Boasting both digital and line-level analog inputs—of the former, a USB input supports up to DSD256, and PCM to 32/384—the Edge A is specified to deliver 100Wpc, operating in what Cambridge calls class-XA, described as less efficient than class-AB but more efficient than class-A. This "seriously beautiful piece of hi-fi" seduced KM with the "creamy" feel of its large, dual-function (volume, source selection) control knob, and sealed the deal with sound that Ken described as "pure solid-state of the silk-ear variety." Through the Edge, bass notes were "clean and round, a little dry," its spatial performance characterized by "some of the best soundstaging I've heard in my apartment: deep and wide, with excellent retrieval of micro- and macrodetail." Writing from his test bench, JA described power output (145Wpc into 8 ohms) that handily exceeded the specs, noting that, "overall, the Cambridge Edge A offers superb measured performance in both the analog and digital domains." Ken's conclusion: "I'd say it's worth your time and your $5000." (Vol.42 Nos. 1 & 4 WWW)

CH Precision I1 Universal Integrated Amplifier: $38,000–$52,000
CH Precision's decidedly modular I1 Universal integrated amp–D/A processor can be had with a variety of extra-cost options, including a USB digital-input board, an Ethernet-input streaming board, an MC phono-input board (with more EQ curves than just RIAA), and a clock-synchronization board that permits the use of an outboard digital clock. In its base form ($38,000), the I1 provides one pair each of balanced (XLR) and unbalanced (RCA) analog inputs, plus an S/PDIF digital-input board and two balanced (XLR) stereo outputs. Echoing the future-proof design of the amp itself is the I1's D/A processor, which is coded into a field-programmable gate array (FPGA); this upsamples 16-bit/44.1kHz PCM and its multiples to 24/352, and 16/48 PCM to 24/384. The I1 handles up to DSD2565, and converts all DSD data to 24/352.8 before playback. Its class-AB output section can provide up to 100Wpc into 8 ohms. Notwithstanding some setup complexities, JVS was able to get from the I1 "some mighty impressive sound," and to the extent it fell short of his own (costlier) reference gear, those were "sins of omission rather than of commission." JVS found the CH Precision's sound to be "clean, strong, and direct," yet it did not "filter out those intangibles that allow the music to elicit a powerfully emotional response." His verdict: "one of the most complete, most neutral sounding, most carefully conceived components I've reviewed." Writing from his test bench, JA praised the I1's "excellent measured performance." (Vol.42 No.2 WWW)

Classé Sigma 2200i: $5500
Specified at 200Wpc into 8 ohms or 400Wpc into 4 ohms, the Classé Sigma 2200i mates a proprietary class-D output section with a front end that converts all incoming analog signals to 24-bit/96kHz digital, after which they're converted to PWM (sampled at 384kHz) before being shed of their carrier frequency and restored to analog for driving the user's loudspeakers. The Classé handles PCM digital inputs up to 24/192, but not native DSD. Preamp-out/power-amp-in jacks are not provided, though the 2200i does offer the somewhat rare luxuries of tone controls and equalization filters. Used with his Monitor Audio Silver 10 speakers, the Classé treated TJN to sound that was dynamically exciting and tonally a bit warm, the latter quality "more inviting than off-putting." While measuring the Sigma 2200i, JA noted some ergonomic wrinkles, including a power-saving feature that persisted in putting the amp into standby even when a signal was present. That sorted, JA observed digital performance of at least 20 bits and "very low distortion and high power below clipping," though he felt that the Classé would not be ideal for very low-impedance loads. (Vol.40 No.4 WWW)

Leben CS600: $6495 ★
Taking its look from 1960s American hi-fi, the beautiful, 32Wpc CS600 has a gold faceplate with green trim and wooden side panels made from solid, fine-grain, Canadian white ash. The amp employs a push-pull topology and can use EL34 or 6L6GC tubes. There is a ¼" headphone jack but no remote control. JM: "The Leben CS600 had a certain, almost indefinable sweetness about it, and a beguiling presentation of inner detail that made me overlook its limitations in dynamics and bass." Partnered with the Harbeth P3ESR loudspeakers, the Leben sounded "simply glorious." (Vol.33 No.6; see JCA's PS Audio review in Vol.40 No.8 WWW)

Line Magnetic LM-518IA: $4450 ★
An original design from a Chinese company that also re-creates classic Western Electric audio gear, the all-tube Line Magnetic LM-518IA is the rare modern integrated amplifier that combines a single-ended output stage with thoriated-tungsten (ie, bright-emitter) output tubes and a tube-rectified voltage rail. The LM-518IA provides three line-level inputs (all RCA) and produces up to 22Wpc into 8 ohms. Tube bias is user-adjustable—but, to HR's disappointment, there is no balance control or mono switch. That said, the amp's "vital energy," among other qualities, has earned it an especially hallowed place in his system: "It is musically alive and vigorous. It plays music with rare charm and sensitivity." Even the SET-skeptical JA was charmed: "For such a design, it offers high power." (Vol.38 No.10, Vol.39 No.10 WWW)

Luxman L-509x: $9495
Integrated amplifiers with tone controls—not to mention switch-selectable outputs for two pairs of speakers, power-output meters, a balance control, a tape monitor button, and a built-in phono stage with MM and MC inputs—are rare beasts. And with its rated power output of 120Wpc into 8 ohms—not to mention its weight of nearly 65 lb—the solid-state Luxman L-509X is indeed a beast, and one whose subtly retro styling impressed KM, who called it "a behemoth of beauty." Ken was also taken with the Lux's sound: "Record after record, the L-509X illuminated every important aspect and area of the recording. It lived and breathed in the air around the notes, consistently creating big, solid, spatially natural images." And even though KM never really warmed to using its tone controls—though he admired the "very smooth, finely graded" adjustments they provided—he concluded that the L-509X was "one of the most intimate-sounding, dynamic, texturally nuanced, truthful purveyors of music of my experience." Writing from his lab, JA found that the L-509X "comfortably exceeded" its output-power specs, and declared the amp "a conservatively engineered design, with low noise and distortion and an excellent phono stage." (Vol.41 No.5 WWW)

Mark Levinson No.585: $12,000 ★
With twice the output power, twice the number of digital inputs for its built-in DAC, and a price tag that's twice as high, the Mark Levinson No.585 integrated amplifier handily exceeds its predecessor, the No.383. (Perhaps they should have called it the No.766?) The class-AB No.585 is advertised as delivering 200Wpc into 8 ohms, and its DAC, which offers resolution up to DSD256, includes an asynchronous USB input alongside two (S/PDIF) RCA inputs, two TosLink inputs, and a balanced XLR jack for AES/EBU. Of its four line-level inputs, one is balanced (XLR). Driving LG's Quad ESL-989 electrostatic loudspeakers—and, via its line-level output, a Tannoy TS2.12 subwoofer—the No.585 impressed him with its "sonic purity and ergonomics." LG declared that, while listening to a recent recording of Beethoven's Symphony 7, "I was reminded of being surrounded by the music, the clearly defined sounds of the instruments, and the ambience of Avery Fisher Hall." Noting, among other things, that the No.585 exceeded its manufacturer's power specs, managing 250Wpc into 8 ohms and 390Wpc into 4 ohms, JA stated that it "offers impressive measured performance." (Vol.38 No.12 WWW)

Moon by Simaudio 340i D3PX: $5800 ★
The 100Wpc Moon 340i is among the growing number of integrated amplifiers that can be upgraded with a plug-in DSD-ready DAC ($900), a plug-in phono stage with MM and MC inputs ($400), and true-balanced XLR inputs ($350). You can get all those options at the start by buying the version Simaudio calls the 340i X ($4700). HR reviewed the latter and especially enjoyed the amp's performance with his Magnepan .7 speakers: "The Simaudio's apparent speed and transparency tamed the Magnepans' inherent sweetness to the point where the .7s began to sound like the high-resolution transducers they are." HR also singled-out for praise the "ridiculously good" performance of the Moon 340i's MC phono inputs, loading characteristics of which are user-adjustable by means of internal jumper blocks, although he noted that his Zu Denon DL-103 cartridge "plays more naturally and in a more relaxed manner into 470 or 1000 ohms than into either of the 340i's choices of 100 ohms or 47k ohms." Reporting from his test bench, JA discovered lowish unbalanced line-level input impedance (7200 ohms at 20Hz and 1kHz), and heatsinking that "isn't adequate for sustained use at high powers"—but otherwise gave this Moon a clean bill of health. (Vol.39 No.3 WWW)

Musical Fidelity Nu-Vista 800: $11,999 ★
The latest in a line of Musical Fidelity products distinguished by their use of nuvistors—miniature small-signal vacuum tubes of such extreme durability that they're often hardwired into circuits—the Nu-Vista 800 is a solid-state integrated amp in which thermionic devices influence both sound and vibe. (The Nu-Vista 800's four nuvistors are illuminated from below and visible from above.) This 330Wpc powerhouse has five pairs of bipolar transistors per channel and provides five line-level inputs, one of them balanced. In addition to describing it as Musical Fidelity's "best-looking product, ever," MF praised the Nu-Vista 800 for its "wholeness and consistency of sound" and for being "relaxed and suave, but not at all soggy or gauzy." And while noting that the amp didn't extract from his recordings the last drop of crispness or detail, MF praised its consistently beautiful sound: "The Nu-Vista 800 drew me in." In measuring the Nu-Vista 800, JA discovered a signal/noise ratio that was "a little disappointing," and very slightly less power output (310Wpc into 8 ohms) than is specified, but was otherwise impressed. (Vol.38 No.11 WWW)

NAD Masters Series M32: $3999
A Masters Series stablemate to their M50.2 digital music player, NAD's M32 combines a Roon-ready, network-connected D/A converter with a class-D amplifier—NAD calls it a DirectDigital Feedback Amplifier—specified to output 150Wpc into 8 or 4 ohms. In addition to its Roon Ready Ethernet socket and single USB input, the M32 provides two line inputs and one MM phono input, and converts all analog signals to digital at a user-selectable sampling frequency of between 48 and 192kHz. JA used the M32 with a variety of loads, from the expected (KEF LS50) to the exceptional (Wilson Audio Alexia 2), and described the NAD's consistent signature as "a clean, clear quality of sound that stepped out of the music's way with every pair of speakers I used." Later, writing from his lab, JA noted higher-than-specified output power—190Wpc into 8 ohms—and praised the phono section for its low RIAA error and high signal/noise ratio, concluding that "NAD's M32 packs a lot of well-engineered performance into its relatively small, discreet case. . . . Highly recommended." (Vol.41 No.5 WWW)

Octave Audio V 80 SE: $10,500 ($11,250 with MM or MC phono)
Shoppers, take heed: the Octave V 80 SE integrated amp is a veritable poster child for the concept of burning-in audio amplifiers before appraising their sound. When first installed in KM's system, the Octave struck him as "the most unlistenable amplifier I've ever tried: bright, forward, and generally eardrum-splitting." One month and nearly 100 records later, the amp had found its "happy-friendly footing," delivering "grain-free highs, very powerful and dynamic bass extension, and neutral, clear-headed sound." Designed and made in Germany, the V 80 SE accomplished all that with two modern Tung-Sol KT150 tetrode tubes per channel, operated in class-AB for specified outputs of 80Wpc into 8 ohms or 120Wpc into 4 ohms. These are supported by two 12AU7 dual-triodes and one 6072/12AT7 dual-triode. An MM/MC phono board is a $770 option, and owners can upgrade their V 80 SE any time with Octave's accessory Black Box power supply ($1200)—not a power supply per se, but an auxiliary reservoir-capacitor bank for the V 80 SE's actual supply. Though the Octave "lacked the tonal color, warmth, and shapeliness of textures" KM enjoys from his Shindo separates, it proved itself "perhaps the single most transparent and neutral machine" ever to grace his system. JA was "impressed by the V 80 SE's measured performance." (Vol.40 No.9 WWW)

Pass Labs INT-60: $9000
The solid-state INT-60 integrated amplifier provides 60Wpc in class-AB, about 30W of which is in pure class-A. (To help confirm that, the needle-and-scale meter that dominates the amp's front panel indicates when the INT-60 slips from one mode into the other.) The Pass has four line-level inputs, two of which offer a choice of single-ended (RCAs) or balanced (LR) jacks, the remaining two offering single-ended only. As shipped from Pass Labs, the INT-60 has 29dB of gain, which can be bumped up to 35dB by removing a pair of internal jumpers. The INT-60 especially impressed HR when he tried it with Zu Audio's Soul Supreme speakers, seeming to mitigate their "extra energy" and rendering their typically lean bass performance "less lean, more muscular, and BIG." And HR found that "the Pass Labs INT-60 drove the [Magnepan] .7s with more subtle magic, slam, and lush joy than I'd previously heard from these speakers." Writing from his test bench, JA noted the Pass's higher-than-specified power output and observed that it offered "respectable measured performance," though the tendency of the INT-60's distortion signature to shift from predominantly second to predominantly third harmonic as the signal frequency rises gave him pause. (Vol.39 No.12 WWW)

Woo Audio WA5: $5899
See "Headphones & Headphone Accessories."

B

April Music Aura Note v.2: $2500 ★
The Aura Note V2 is a compact and sleekly styled integrated amplifier (125Wpc) with built-in CD player, USB DAC, FM tuner, Bluetooth receiver, and headphone amp. Its USB DAC, addressed by a USB Type A socket on one side of its casework, is good to 192kHz—it uses a 24-bit Cirrus Logic D/A chip—and its class-D amplifier output section uses ICEpower modules supplemented by a switch-mode power supply. The Aura Note V2's playback of CDs had "color and clarity, spatial presence, and a good sense of momentum and flow," according to AD, though its amplifier lacked a bit of texture and richness when compared to the best. He also noted some harshness on extreme peaks when using an outboard phono section into the Aura's line-level input. All in all, AD concluded, "the V2 offers a generally very good musical and sonic experience." Writing from his test bench, JA noted that the Aura Note V2's CD player exhibited one of the highest levels of tolerance of defective discs he's ever observed, but also found that its Aux inputs could be overdriven with input signals greater than 3.3V, thus underscoring the need for caution when matching a phono preamp and cartridge to this otherwise recommendable all-in-one box. (Vol.39 No.4 WWW)

Cary Audio SLI-100: $5995
A push-pull tubed integrated amp that uses two KT150 pentode tubes per side, operating in Ultralinear mode, to output 100Wpc, the SLI-100 provides the user with four line-level inputs, all unbalanced, and a choice of 8 or 4 ohm output taps. The output section is biased for class-AB and employs 4dB of negative feedback. In addition to the four output pentodes, the Cary uses four small-signal tubes—two 6922s, two 6SN7s—and splits the signal phase with a cathodyne ("split-load") phase inverter, for which HR expressed preference when compared with the more common long-tailed pair/dual-differential stages. Also integral to the design is a voltage-gain stage constructed with shunt-regulated push-pull architecture, also a Herb favorite. This all added up to an amplifier that allowed violinist Joseph Szigeti, playing Bartök, to wring the most "tearjerking presence and texture" from HR's Harbeth M30.2 loudspeakers. In measuring the SLI-100, JA found "a slight degree of overshoot" in the amp's squarewave reproduction and, far worse, strikingly less output power/higher distortion than specified: "I was disappointed in the Cary Audio SLI-100's measured performance." (Vol.41 No.12 WWW)

Cary SI-300.2d: $5995
In years past, when the number 300 appeared in a Cary Audio product name, you could bet it referred to a certain low-power output tube; today, in the context of Cary's SI-300.2d integrated amp, it stands for output power—as in 300Wpc (into 8 ohms). The solid-state SI-300.2d also incorporates a DAC that offers PCM to 384kHz and DSD up to DSD256. (DSD is handled natively, except where the signal is streamed from a Mac—in which case DSD is handled as DoP.) The option of upsampling PCM to various higher sampling rates or to DSD is provided, although it does not apply to the Cary's USB digital input. In his listening tests, KM remarked on the SI-300.2d's "extreme resolution, and never at the cost of tonal richness or spatial substance." KM described the Cary's sound, with Elac B6 loudspeakers, as being "as transparent as a fall sky, and as tonally even-keeled as I've heard in my nearfield setup," and concluded, "this was not the sound of your father's Cary tube amp." JA's test-bench findings were a decidedly mixed bag: "The amplifier itself is a straightforward, competently engineered" design, he wrote, but he found some irregularities in the performance of Cary's DAC, describing its upsampling behavior, in particular, as "perverse." (Vol.39 No.12 WWW)

GamuT Di150 LE: $12,990
Like all of the amplifiers in GamuT's line, the Di150 LE integrated boasts a unique (in perfectionist audio) output architecture: rather than using multiple output devices per phase, the solid-state, push-pull Di150 LE has only one transistor per phase, and thus two per channel. According to company founder Ole Lund Christensen, this is done to banish the timing and phase distortions that plague other designs—and by using massive transistors (think: arc welder) and robust driver stages, GamuT achieves in the Di150 LE a none-too-shabby 180Wpc into 8 ohms or 360Wpc into 4 ohms. Listening to the GamuT with his DeVore Fidelity Orangutan O/93 speakers, KM heard multiple traits: "a hard-charging, forceful delivery of the music, strong micro- and macrodynamics, stupendous bass reproduction, a wide and layered soundstage, and . . . 'black' backgrounds . . . notes flew from the Di150 LE with purpose and punch." Reporting from his test bench, JA noted a low output impedance and higher-than-specified output power, and praised the GamuT as "a well-engineered solid-state amplifier." (Vol.40 No.4 WWW)

Heed Audio Elixir: $1395 $$$
Heed, pronounced hid, is a Hungarian manufacturer whose generally affordable solid-state amplifiers feature deliberately non–direct-coupled output stages; indeed, Heed suggests that an amp with output capacitors—which they call translator capacitors—is better suited for "the stress-free generation of air-pressure changes [into] the sound we hear." Whether for that reason or not, KM was mightily impressed with this 50Wpc, MM phono–equipped integrated amp, being "immediately struck by the Elixir's superb sense of flow. The Elixir portrayed dynamic swings with a natural and effortless musicality." Ken's conclusion: "That so much amplifier is available for $1195 should have music lovers dancing, unclothed and unhinged, across fields and meadows, melodies on their lips, as creatures great and small join them in song." JA's measurements uncovered a bit of RIAA error in the phono section—associated with "a slightly rich balance"—and notably low power into a low-impedance (2 ohm) load, but noted that the Elixir's distortion signature "will also render it easy on the ear." (Vol.39 No.11 WWW)

Naim Audio Uniti Nova: $7499
The star of Naim's rebooted Uniti line, the Nova combines an 80Wpc integrated amplifier with a media player and streamer, the latter supporting Tidal and Spotify. The Nova offers Bluetooth aptX HD and WiFi connectivity, and provides vTuner Internet radio as well as support for most music-file types, up to 384k PCM and DSD128. All user controls are accessible via an included remote control, Naim's downloadable app, and a full-color front-panel LCD display that KM described as "lovely," supplemented with a top-panel rotary control. Ken was enchanted with the Uniti Nova's radio function, and found its file-playing capabilities ergonomically comforting—"I was surprised by the Nova's ease of setup and practically instantaneous response"—and sonically rewarding: "file after file drove my jaw floorward as my ears reveled in the Nova's beautiful sound." KM's verdict: "the Uniti Nova is practically a bargain. Definitely, effusively, highly recommended." Apart from noting some anomalous behavior with 96 and 192kHz data—their responses were down by 9dB at the ultrasonic frequency of 29kHz—JA wrote from his test bench that "the Naim Uniti Nova's measured performance "reveals it to be well sorted, as they say in the UK." (Vol.41 No.3 WWW)

Naim Nait 2/AVO Ultimate Upgrade: $2190 plus cost of Nait 2 $$$
In 1988, the quasi-complementary, class-AB Nait 2—a revised version of Naim's budget-priced, entry-level Nait—distinguished itself as an exceedingly fine-sounding integrated amplifier and one of the stars of Naim's product line. Fast-forward to 2016, when vintage examples of the Nait 2, no longer in production, continue to win raves from budget-conscious audiophiles—although by now most Nait 2s require servicing. Enter AV Options, which employs ex-Naim staffers and offers various levels of service and rebuilds. Their Ultimate Upgrade for the Nait 2 ($2190) involves replacing and recalibrating 14 transistors (including the output devices) and scores of passive parts (including jacks and sockets), plus deep-cryo treatment of the original transformer and other components. AD loved listening to the AVO-upgraded Nait 2, praising its "profoundly excellent sense of momentum and timing" and offering special praise for its great-sounding MM phono section. Bonus points for being able not only to drive Quad ESLs but to make them sing. (Vol.39 No.5 WWW)

Outlaw Audio RR2160: $849 $$$
The RR2160—or, as Outlaw Audio calls it, their "Retro Receiver"—marries a 110Wpc class-AB integrated amplifier to an FM/AM tuner of the traditional sort, along with an MM/MC phono stage. Its tone controls—yes, tone controls!—and bass-emphasis switch hark back to an era of mustaches, flared trousers, and loudspeakers with sculpted-foam grilles, yet the RR2160 doesn't skimp on modern conveniences, including Ethernet connectivity, HD radio, an MP3 input, a headphone amp with independent volume controls, and a 24/192 DAC with USB, coaxial, and optical inputs. After being broken in and warmed up, the Outlaw rewarded HR with "a generously big, warm, articulate sound." Used with a CD transport, the RR2160's Burr-Brown–based DAC didn't reach the same performance heights as more expensive outboard processors, yet nonetheless surprised Herb with its "unfettered verity." The Outlaw's MM phono inputs performed well when addressed with a good-quality step-up transformer, though HR was disappointed by the lack of adjustability in its MC inputs. And its headphone section "far exceeded" HR's expectations. Writing from his test bench, JA noted the Outlaw's "significantly" higher-than-specified output power, the admirably low output impedance of its headphone amp, and its "superb" phono stage, though he was "somewhat disappointed by the measured performance of its digital inputs." HR's conclusion: "a conspicuously good-sounding audiophile product at a ridiculously low price." (Vol.40 No.12 WWW)

Unison Research Unico Primo: $2495
The entry-level integrated from Italian manufacturer Unison Research, well known for their more radically styled power amps, the Unico Primo mates a tubed front end (one ECC83/12AX7) with an 80Wpc solid-state output section running in what Unison calls "Dynamic class-A." An optional plug-in board, also solid-state, provides MM/MC phono capabilities. (The Unico Primo is available without phono for $2400.) In addition to boasting what KM described as a volume control with "the creamiest action I've ever laid fingers on," the Unico Primo "charged hard 24/7, with enough dynamic gusto to compel music mightily." KM added that the slightly warmish Unison Research amp "struck an unusual balance between superior resolution in the treble to midrange and weighty low-end fundamentals that were less than accurate." Reporting from the test bench, JA noted a bit more distortion and noise than desired, but very good phono-stage performance. Optional black faceplate adds $150. (Vol.39 No.7 WWW)

C

Arcam FMJ SR250: $3600
Arcam's FMJ SR250 is the rare two-channel amplification product that contains room-correction software (Dirac Live), a feature that helped it overcome our usual reluctance to review A/V receivers. The FMJ SR250 has seven analog inputs and 15 digital inputs, the latter including USB, Ethernet, S/PDIF (RCA, TosLink) and no fewer than seven HDMI sockets. (The USB and Ethernet inputs are limited to 48kHz; the other inputs max out at 192kHz.) The class-G amplifier stage—the power transistors are fed by two separate sets of power-supply rails, microprocessor-selected depending on the demands posed by the input signal—is specified as outputting 90Wpc into 8 ohms. Before calling into play its room-correction software, KR felt the Arcam's bass performance was "good, solid, and balanced," its soundstaging "convincing." With Dirac Live enabled and dialed in, the Arcam impressed Kal as "even more satisfying and communicative." Less impressed was Measurer-in-Chief JA, who, though noting the Arcam's "powerful" and "low distortion" amplifier section, was dismayed by the way its USB input handled digital signals, and by a phase discrepancy between the channels on both its USB and S/PDIF inputs. He declared the SR250's digital inputs "inadequate for serious listening." (Vol.40 No.6 WWW)

NAD C 328: $549 $$$
The budget-priced NAD C 328 combines Bluetooth connectivity, a 24-bit/192kHz DAC based on a Cirrus Logic chip, an MM-ready phono stage, and a Hypex-based class-D amplifier rated at 40Wpc into 8 ohms—all in an enclosure whose size and appearance are closer to those of the company's legacy products than this amp's contemporary stablemate, the odd-looking D 3020. Cynical readers might expect less than the best sound from such a humble thing—and indeed, during his time with the C 328, KM found a few recordings that coaxed from it a bit of treble harshness, and a few others that lost a bit of flesh and blood on their trip through the NAD. But when mated with the right speakers—KM got the best results with Elac's Debut B6 ($279/pair)—this amp "consistently made music with a detailed, very dynamic, natural sound." In measuring the NAD's amplifier section, JA uncovered a superbly high signal/noise ratio, higher-than-specified output power, and very low distortion, with similarly excellent performance from the phono section; the C 328's onboard DAC was only slightly less distinguished, although it proved capable of more than 19 bits' worth of resolution, which is very good indeed. (Vol.41 No.10 WWW)

Peachtree Audio nova300: $2199–$2299
With their nova300 integrated amplifier-DAC, Peachtree Audio made a number of transitions: from iPod docks to Lightning connectors and WiFi; from tubed preamp buffers to all solid-state; from line-only preamps to an onboard MM phono preamp; and, most notably, from Chinese to Canadian manufacture. Other characteristics endure, including the attractive wood wrap—made even more attractive by an Ebony Mocha finish option—and a class-D output stage, this one based on ICEpower modules, for a power rating of 300Wpc into 8 ohms. The nova300 also boasts double-DSD capability alongside 32/384 PCM, and Peachtree's Dynamic Noise Elimination (DyNEC), which is claimed to eliminate, among other noises, those associated with the display screens of smartphones and tablets. In a review that proved controversial, AD praised Peachtree Audio for the nova300's excellent phono section and for its overall good momentum and drive, but criticized the graininess of its treble range. In their Manufacturer's Comment in the same issue, Peachtree took issue with Art's pairing of the nova300 with his extremely efficient Altec Flamenco speakers, calling it a "mismatch," though they held out the possibility of a flaw in the review sample, which they said was "on its way to our engineers for a testing, just in case." We were disappointed never to have heard back about the first sample, which, in his measurements, JA described as having "a high level of switching noise on its output." However, for the December 2017 Stereophile AD wrote a Follow-Up based on a second sample of the nova300, which he tried with the very contemporary Wharfedale Diamond 225 speakers. Art thought this pairing sounded "slightly less edgy" than his earlier experience, although the sound remained "dry and crisp overall." (Vol.40 Nos. 6 & 12 WWW)

PS Audio Sprout100: $599 $$$
Designed in Boulder, Colorado, and built in China, the PS Audio Sprout is a compact (6" W by 1.75" H by 8" D) integrated amplifier with built-in MM phono preamp, USB D/A processor, Bluetooth receiver, and ¼" headphone jack. In its original version, reviewed in the May 2015 Stereophile, the Sprout's class-D power amp could deliver up to 33Wpc across an 8-ohm load. HR observed that the Sprout occasionally lent the sound "a trace of darkness—not grayness or lack of color," but found the little amp consistently engaging, musically: "the Sprout demonstrated an ability to engage my attention and keep it locked on the space, character, and artistry of the music being played." HR also felt that the Sprout's Bluetooth wireless performance was "richer, more detailed, less hollow and vapid than any Bluetooth sound I've tried so far," though he found the amp's sound through headphones less rich than through speakers. Apart from an impedance-related response-curve bump centered at 67Hz, JA's measurements uncovered nothing untoward. In 2018 the Sprout was redesigned and christened the Sprout100. Refinements include an increase in power to 50Wpc into 8 ohms or 100Wpc into 4 ohms and installation of an ESS Sabre DAC chip that bumps up the resolution from 24/192 to 24/384. Whereas HR thought the original Sprout sounded best through its phono input, he found the Sprout100 "exactly the opposite. Its digital input seemed more articulate and vivacious." In all, Herb appreciated the Sprout100 as "an easy-to-use lifestyle product," albeit one lacking in appeal to seasoned audiophiles. (Vol.38 No.5, Vol.41 No.11 WWW)

Rega Research Brio: $995
This latest incarnation of the Rega Brio integrated amp—the company's "best-selling electronic product ever," according to company head Roy Gandy—retains the original version's design brief: class-AB architecture that emulates class-A performance without class-A heat. Refinements in the new amp include metal-film resistors in its feedback circuit and some power-supply refinements lifted straight from the Brio's original inspiration, a 1970s design from the pages of Wireless World. Features include a moving-magnet phono input, four line-level inputs, and all-new casework. After trying the Brio with his DeVore Orangutan O/93 loudspeakers, KM declared, "The Brio controlled bass notes fairly well[, but] its crowning glory was its extended and natural top end." Although it didn't reward Ken with "the last word in transparency or absolute detail," the Rega Brio impressed with its more musical characteristics: "big tone, big beat, big ambitions." After measuring the Brio, JA praised in particular the "superb" overload margins of its phono section, and declared the amp "well-sorted" overall, although he did note that it runs hot. (Vol.40 No.10 WWW)

Rogers High Fidelity 65V-1: $4000
From Rogers High Fidelity comes a truly distinctive product: a tubed stereo integrated amplifier whose output architecture is switchable between Triode and Ultralinear modes. Also user-selectable are the 65V-1's output tubes: at the time of purchase, the buyer selects EL34 or KT88 pentodes, though the tubes not taken, if purchased separately, can be used at any time with no modification of the amp. Either way, the 65V-1, which operates in single-ended mode—and thus pure class-A—is specified to produce less than 0.5% THD at 1Wpc and less than 3% at 10Wpc, with a peak output of 25Wpc. Yet for all that old-school technology, the Rogers amp comes with an app that transforms the user's iOS device into an output-power meter calibrated in watts (0–25W), the data sent from amp to app via a built-in Bluetooth transmitter. According to HR, with some music, the 65V-1 "let the vivid, undoctored reality of [the recordings] come through with eerie, preternatural directness." Herb also noted that, when used with the very efficient DeVore Orangutan O/93 speakers, the Rogers amp played "loudly and dynamically enough to provide genuinely satisfying sound." That said, JA's measurements revealed lower-than-specified output power—270mWpc at 1% THD, 2.275Wpc at 3% THD—and distressingly high output impedance. Independent of this, Herb concluded: "an uncommon audio product in search of uncommon audiophiles." In a Follow-Up, AD praised the ingenuity and audacity of bringing such an unabashedly fun product to the market, and noted the Rogers's abiding musicality. But through his own DeVore O/93s he also heard a few "gritty" dynamic peaks from the 65V-1 that kept him from cozying up to the amp's sound. (Vol.41 No.6, Vol.42 No.1 WWW)

Editor's Note: There are no Class D integrated amplifiers listed.

Deletions
Allnic T-1800, Cambridge Audio Azur 851A, Creek Audio Evolution 100A, Jadis Orchestra Reference Mk.II, NAD D 3020 V2, Rogue Audio Sphinx, all not auditioned in too long a time.

Complete Audio Systems

A

Devialet Gold Phantom: $2990 each
In a setting as idyllic as it was ideal, at least in a commercial sense—the samples were auditioned in an apartment on the rue des Ursulines in Paris, the city of their manufacture—Devialet's top-of-the-line Phantom powered speaker whetted JCA's appetite, and on returning home to his superior-sounding NYC apartment he requested review loaners. There, auditioned with Devialet's Tree stands ($375 each), Dialog dedicated router ($329), and Remote remote volume control ($149), a stereo pair of Gold Phantoms "'disappeared' nicely, as befits a phantom." (The Phantoms are sold singly and, per Devialet, are commonly used as mono playback systems.) JCA praised the system's "stark, disciplined" bass, which he described as surprisingly "deep, without bloat," though he wouldn't have minded more generous low-frequency response. He also praised its abundant soundstage depth, though he felt that the speakers' class-D amps didn't "resolve the unique timbres of instruments as well as other systems I've heard." Phonophiles will find the Devialet system fails on another front: it has no analog inputs. But for others, according to JCA, the Gold Phantom system is "a serious value" and "could be just the thing." (Vol.40 No.11 WWW)

B

Bluesound Vault 2, $1199; Powernode 2, $799; Node 2, $499; Pulse 2, $699; Duo 2: $999 ★ Bluesound is a new line of whole-house sound products from the Lenbroo1k Group, owners of NAD and PSB. The Bluesound Vault ($1999) which requires an Ethernet connection to the Internet, is an 11.5" W by 9.3" H by 8.1" D box containing an optical drive, a 24-bit/192kHz Cirrus-Logic sigma-delta DAC, and 1TB of storage. Inputs are Ethernet, WiFi, USB Type A, and, by means of an optional dongle, Bluetooth. Outputs include an analog RCA pair and digital TosLink capable of passing up to 24/192 data to an external DAC. The Bluesound Powernode ($799) which looks identical to the Vault but is slightly smaller, is a network player with a 24/192 DAC. The Powernode has the same complement of inputs as the Vault, while its outputs are a subwoofer-out jack (RCA) and two pairs of binding posts for speakers. The Powernode can operate with or without the Vault; in the latter case, the Powernode will access music files from the user's NAS. The Bluesound Node ($499) is—get ready for it—rather like the Powernode, but without (output) power. The Bluesound Duo ($999) is, in the words of ML, "a straightforward satellite-and-(self-powered)-subwoofer loudspeaker system designed by Paul Barton of PSB Speakers [and] meant to be powered by the Powernode." And the Bluesound Pulse ($699) is a 13.4-lb "network-ready boom box" that runs on AC wall current. With Bluesound products scattered throughout his home and with the system as a whole accessing files on his QNAP NAS, ML found the sound of the Bluesound "ecology" to be pleasantly rich and full, if, in some instances, a bit dark; with regard to the latter quality, inclusion of the Auralic Vega DAC restored the missing sparkle. "I enjoyed my time with the Bluesound components," ML stated, noting that the Pulse was perhaps the pleasantest surprise of the lot. Current v2 versions are cosmetically different from those reviewed but otherwise identical. (Vol.37 No.7 WWW)

Apple HomePod smart speaker: $349
Apple, a company unfazed by the five-dealer requirement for getting a review in Stereophile, refers to their new HomePod as "a breakthrough speaker that adapts to its location and delivers high-fidelity audio wherever it's playing." Reviewer JCA refers to it as "a sophisticated, high-tech, 5.5-lb sound computer with many transducers and lots of unorthodox engineering." This "smart" speaker, so called for its integration with the Apple Music streaming service and Siri, Apple's notorious virtual assistant/speech-recognition interface, contains a single 4" woofer and seven horn-loaded tweeter/midrange thingies, each with its own amplifier—yet those aren't the only transducers. Also inside this 6.8"-tall cylinder are seven microphones that serve to both receive the user's voice commands and sense the HomePod's surroundings, as part of a complex equalization and dispersion-control system. Use of the HomePod requires WiFi Internet access and either an Apple iPhone 5s or later, or one of various recent models of iPad or iPod Touch, all running iOS 11.2.5 or later; full functionality also requires an Apple Music subscription. Although sold singly, the HomePod is not, strictly speaking, a monophonic device; as JCA noted, "With stereo recordings, it uses both channels of the signal, comparing phase relationships to differential direct sound from ambience" to, ultimately, add spaciousness to the sound. And spaciousness is what JCA heard from a favored mono Billie Holiday track—that and a "richer and more resonant" sound from Lester Young's sax than JCA expected: "I even wondered if I was listening to a different tenor player." Yet Jim felt that Apple "has made some tasteful and judicious choices" in voicing the HomePod, declaring it "an easy recommendation for anyone looking for an affordable wireless speaker." One issue later, JCA reported on firmware and operating-system updates that allow two HomePods to be used as a true stereo pair. With two HomePods in his living room, each perched atop its own 22"-tall speaker stand, JCA enjoyed deeper-than-expected bass (if still lighter than that from his main system) and "excellent stereo sound with remarkable imaging." He proclaimed the combo of two HomePods with an iPhone or iPad "the best-sounding wireless system I've heard at or near the price." (Vol.41 Nos. 8 & 9 WWW)

Deletions
Eclipse TD-M1 no longer distributed in the US.