Recommended Components

Headphones & Headphone Accessories

Editor's Note:

We strongly recommend those interested in headphone listening visit our sister website, www.InnerFidelity.com, which is edited by Tyll Hertsens.

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Audeze The King: $3995
Created by legendary electronics designer Bascom H. King—geddit?—the hybrid tube/MOSFET The King headphone amplifier is built into a large (12.8" wide by 4.3" high by 11.8" deep) case supported by four substantial, shock-absorbing feet. It operates in class-A, and its two parallel, front-mounted, ¼" outputs can be calibrated by the user for specific headphone models. HR enjoyed his time with the "squeaky-clean" King, and praised the "mute-spectator neutrality" of its "clean, sober, workmanlike audio presentation." HR tried The King with 10 different headphones and declared that it allowed nine of them to "sound more lucid than ever." JA's measurements, described in a Follow-Up, revealed noise-floor anomalies that lacked corresponding audible effects—apparently this problem has been fixed in production—otherwise, he said, "there are lots of things to admire in the measured performance of Audeze's King." (Vol.39 No.12, Vol.40 No.1 WWW)

Audeze LCD-4: $3995
For their new LCD-4 headphones, Audeze uses a variation on their tried-and-true planar-magnetic technology, with a vanishingly thin diaphragm of aluminized film suspended between a push-pull array of Double Fluxor magnets (flux density: 1.5 teslas) and impedance-matching Fazor waveguides on the outer surfaces of the earcups. The supplied cable has left and right mini-XLRs for the earcups and a ¼" plug at the other end, with no adapter supplied: the LCD-4s are not intended for use with telephones. Used mostly in single-ended mode, the LCD-4s impressed JA as bass "champions" that "spoke cleanly and evenly." JA also wrote that the new Audezes "excelled in the midrange," and noted that he enjoyed the LCD-4s' "sweet" treble performance more than Tyll Hertsens did in his own review of the LCD-4s for InnerFidelity.com. Writing from his test bench, JA also noted an impedance of 156 ohms (as opposed to the specified 200 ohms) and a very benign electrical phase angle, making for an easy-to-drive pair of 'phones (but beware their lower-than-average sensitivity). The verdict: "The best-sounding headphones I've heard in the 45 years since I bought my first high-end cans." (Vol.39 No.7 WWW)

Audeze LCD-X: $1699 ★
These large, luxurious, circumaural headphones have planar-magnetic drive-units with a thin-film diaphragm energized by arrays of powerful neodymium magnets on both sides. They employ Audeze-patented Fazor elements, said to guide and manage the flow of sound in the headphone. The circular drivers are housed in polished, black-anodized aluminum earpieces, with generously sized pads, of either lambskin or leather-free microsuede, filled with foam. Adjustment is via notched, chromed metal rods attached to each earpiece, which fit into the sprung, leather-covered headband. The LCD-Xes produced a seductive, compelling overall sound, with precise imaging, rich mids, smooth highs, and clean bass, said JA. Compared to his longtime reference Sennheiser HD650s, the LCD-Xes resolved more detail, produced the more convincing sense of recorded ambience, and provided deeper bass. "Highly recommended!" JA concluded. (Vol.37 No.3 WWW)

Ayre Acoustics Codex: $1795
Described by designer Charley Hansen as "deliberately built to the lowest price point we've ever done," the Ayre Codex D/A headphone amplifier uses a 32-bit ESS DAC chip to provide up to 384kHz PCM or DSD128 resolution via its asynchronous USB input. (An optical input is also provided but is not compatible with all devices.) Both balanced and unbalanced headphones and headphone cables are supported. JI wrote, of listening to the Codex through his Audeze LCD-X headphones, "there was plenty of detail to go around, as well as the ability to hear into the space with the performers." He elaborated: "Probably the best words to describe the Codex's aural character are neutral and detailed—and add Control, with a capital C." Writing from his test bench, JA observed that "the Codex offers excellent measured performance." (Vol.39 Nos.6, 7 & 9 WWW)

Benchmark Media Systems DAC2: $1995
See "Digital Processors" (Vol.37 No.2 WWW)

Chord Mojo: $529
Fans of James Cotton and Muddy Waters will be dismayed to learn that the name of Chord's latest D/A headphone amplifier is a contraction of mobile joy. But that is likely to be the only disappointment associated with the chunky little Mojo—which, like Chord's more expensive Hugo TT, eschews an off-the-shelf DAC chip in favor of its own proprietary code, implemented with a field-programmable gate array (FPGA). The Mojo even runs the same Rob Watts–designed digital filter as its dearer stablemate, and its USB input is compatible with PCM up to 192kHz and DSD up to 11.29MHz (DSD256). No less striking are its three matte-surface glass control balls, which change color to indicate various functions and statuses. Used by JA with a variety of partnering gear—the Audeze LCD-X headphones suited it especially well—the Mojo "combined authoritative, well-defined low frequencies with smooth, detailed highs and excellent soundstaging." JA the measurer confirmed "performance that is superb for a portable device, and would not be out of place in a high-priced conventional D/A processor." But the last word goes to JA the listener: "Wow!" (Vol.39 No.2 WWW)

Focal Elear: $999
Offered as a comparatively affordable alternative to Focal's Utopia headphones ($3999), the Elears are made of slightly less costly materials—most notably an aluminum-magnesium alloy instead of beryllium for the domes of its drivers, and aluminum instead of carbon fiber for the yoke. As HR discovered, "both Focal models have delicate, beautifully rendered trebles, and . . . both sort out complex music better than any of their competitors." But he heard from the Elears a slightly thicker sound in the lower midrange and upper bass—qualities that didn't always work against the less expensive 'phones; he suggested that the humbler dome "adds an extra, enjoyable measure of tonal color that's absent from the more pure and empty-sounding Utopias." (Vol.39 No.12 WWW)

Focal Utopia Reference: $3999
The fully open-backed, circumaural Focal Utopias are designed around proprietary, full-range, beryllium-dome drivers that, uniquely, have no voice-coil formers: each coil is fastened directly to its dome, in a crease near its surround. The yokes are made of carbon fiber, and the earcups and headband are covered with lambskin. HR described the Utopias as capable of producing "a gut-level realism that is rare in high-end audio," adding that the Focals are "lightning-fast, extremely open, and profoundly uncolored." (Vol.39 No.10 WWW)

HiFiMan HE1000 V2: $2999
Claimed to have the largest and lightest diaphragms in the history of headphones, the planar-magnetic HiFiMan HE1000 V2 builds on the strengths of the original HE1000, offering lighter weight (14.8 vs 16.9oz) and sturdier cables, plus ear-shaped earpads of thicker "pleather." Impedance is 35 ohms, sensitivity 90dB. According to HR, the V2s are "extremely transparent, and excel at imaging and spatiality." No less important, Herb noted, was that the V2s "did serpentine flow better than any headphones I know." He added that their low sensitivity "never once let the music hesitate, or lack for sparkle or momentum." Icing on a good-sounding cake: the V2s impressed HR as being "way more comfortable than any Audeze model." (Vol.40 No.4 WWW)

HiFi Man HE 400i: $449 $$$
The least-expensive planar-magnetic headphones ST knows of, the HE-400i offers a 32 ohms impedance and 93dB sensitivity, and performs at its best with a dedicated headphone amplifier. The sound is "crisp, clean, clear, and lightning fast, as music is in real life. This is true of the bass, too. Indeed, the sound is seamless from the top down or the bottom up," summed up Sam. (Vol.37 No.12)

JH Audio JH16 Pro: $1149 ★ (plus custom earmold fee)
Designed by Jerry Harvey (ex–Ultimate Ears), the top-of-the-line JH Audio in-ear monitor uses eight precision-balanced armatures (two dual-armature woofers, one dual-armature midrange, and one dual-armature tweeter) and a three-way crossover. It delivered clean transient attacks, a smooth midrange, big-hearted bass, and a detailed soundstage, said JA. The JH16 Pro exhibited excellent overall performance when driven directly by JA's iPod Classic, but offered more low-bass energy and greater articulation when driven by the Ray Samuels Emmeline The Tomahawk headphone amplifier. Price includes plastic Otterbox carrying case, felt drawstring bag, and cleaning tool. (Vol.34 No.8 WWW)

JPS Labs Abyss AB-1266 Phi: $4495–$7495
For those who regard the JPS Abyss AB-1266 Phi headphones as prohibitively expensive, HR offers perspective by suggesting that they, like such "notorious legacy products" as the Wilson Audio WAMM loudspeaker of 1983 and the Audio Note Ongaku amplifier of 1993, "exist in categories of price and performance all their own." The Abyss 'phones are built into black-anodized aluminum frames, and use single-magnet planar-magnetic drivers, separated from the wearer by rotatable lambskin earpads held in place with magnets. Specs include an 88dB sensitivity and an impedance of 42 ohms. After listening to a Schoenberg piece through the Abysses driven by the Woo WA5 headphone amp, HR observed: "I scribbled the phrase perfectly natural several times. I never felt more kindred or connected to Schoenberg." He also suggested that the Abysses "delivered detail and soundstage images with an uncannily visual—nay, infinite—depth of field." (Vol.40 No.8 WWW)

Linear Tube Audio MZ2: $1235
Designed by David Berning and built in Washington, DC by Linear Tube Audio, the MZ2 (originally called the microZOTL2.0, ZOTL standing for Zero-hysteresis Output TransformerLess) is a 1Wpc integrated amplifier that doubles as a headphone amp and triples as a line-level preamp. Each channel uses a 12AT7 dual-triode tube for voltage gain and phase inversion, while the two halves of a 6SN7 dual-triode comprise a single-tube, push-pull, class-A, OTL output stage. HR delighted in the sound of the microZOTL driving DeVore O/93 and Zu Soul Supreme speakers—with the latter, he said, "musical flow seemed more slippery and alive, like a trout in a clear mountain stream"—and with JH Audio Roxanne headphones, he said, "the midrange was pure and right." And "because of its radical transparency," says HR, the microZOTL2.0 "would hold its own" as a line stage "in a cost-no-object system." According to JA, while the microZOTL2.0's test-bench performance wasn't without wrinkles, "this unusual design measured well in some respects, particularly in how its linearity was not affected by the load impedance." (Vol.39 No.6 WWW)

Meridian Prime: $2000
Notable as much for its praiseworthy headphone amplifier and analog inputs—which, when driven by the output of an Auralic Vega DAC, sounded "rich and warm" through JA's Audeze headphones—the Meridian Prime's asynchronous USB DAC handles incoming datastreams at 16 and 24 bits and sampling rates up to 192kHz, and applies to all incoming data an "apodizing" reconstruction filter. While noting the Prime's lighter weight and smaller body as compared with the Vega, JA praised the Meridian DAC's "clearer balance." Also singled out for praise was "the palpable way [the Prime DAC] had with imaging"—which, JA mused, might be attributable to that reconstruction filter. Use of Meridian's optional Prime power supply ($1295) in place of the stock wall wart added "a touch more body, a tad more authority." In his measurements, JA found discrepancies in the Prime's 24-bit performance but praised its well-engineered analog section. The verdict: "A cautious recommendation . . . for this beautifully finished, excellent-sounding headphone amplifier." In new measurements made for his November 2015 Follow-Up, JA confirmed Meridian's hypothesis that the aforementioned discrepancies were caused by the Prime Power Supply. Still, he mused, "Why did I prefer the sound of the Prime with the underperforming Prime Supply?" As of the spring of 2016 decodes MQA data. (Vol.37 No.10, Vol.38 No.11, Vol.39 No.9 WWW)

Meridian Explorer²: $299 $$$
Hailed by Jim Austin as "the cheapest ticket into the world of MQA"—aka Master Quality Authenticated, the digital-audio format that has energized portions of the audio community and hopes to do the same for the recording industry—this reboot of Meridian's popular portable DAC-headphone amp offers more processing power than its 2013 predecessor. Specifically, its XMOS processor upsamples lower-frequency inputs to 176.4kHz or 192kHz—and, of course, allows the Explorer² to decode MQA files. Used primarily with his Sennheiser HD 650 headphones, the Explorer² impressed JCA as "very pleasant to listen to: It conveyed plenty of information in a relaxed way." In comparison, the similarly sized and priced Apogee Groove was, in JCA's words, "a little punchier . . . and a little less smooth," and the Groove lacks the Meridian's line-out jack. Of his experience with one of a handful of (unfamiliar) MQA-encoded tracks, JCA wrote of being "struck by a remarkable sense of intimacy, a close connection to the solo instrument." Writing from his test bench, JA observed that, "Like its predecessor, the Meridian Explorer² offers superb measured performance." JCA's conclusion: "a fun, capable audio device." (Vol.39 No.6 WWW)

Pass Labs HPA-1: $3500
Also usable as a line-level preamp—it has a pair of single-ended output jacks (RCA) to allow just that—the Pass Labs HPA-1 is a perfectionist-quality headphone amplifier that uses a MOSFET-based current-feedback amplifier to drive headphones ranging from 15 to 600 ohms. Its single headphone-output jack, also single-ended, is a Neutrik locking jack sized for ¼" plugs. After auditioning the HPA-1 with a variety of 'phones from Audeze, AudioQuest, and Master & Dynamic, JA declared that, "in bass quality and authority, and in midrange transparency, the Pass Labs HPA-1 is without peer." JA also brought the HPA-1 to his test bench, where it stood up to everything he could throw at it (well, not literally), prompting the appraisal: "superb audio engineering." (Vol.39 Nos.7 & 9 WWW)

Sennheiser HD 650: $499.95 ★
The HD 650s are an evolution of Sennheiser's very successful HD 600 open-back dynamic headphones, claimed to provide superior results due to hand-selected parts with closer tolerances and the use of a specially developed acoustic silk for the driver diaphragms. Compared to the Grado SR325i, the Sennheisers sounded richer but slightly darker. JM found that their very effective seal created a resonant cavity that produced "bass that is both quite deep and a trifle indistinct." Compared to the Audeze LCD-Xes, the HD650s had a similar overall sound, but lacked bass control, detail resolution, and ambience retrieval, said JA. (Vol.28 No.6, Vol.31 No.9, Vol.37 No.3 WWW)

Sennheiser HD 600: $399.95 ★
WP, KR, and ST were unanimous in calling these the best dynamic headphones they've ever heard. "The only ones with which I have ever been physically or sonically comfortable," says KR. "Sennheiser has kept all of the qualities that made the HD 580 among the best of its breed, and in several areas has even managed to better it impressively," according to WP. Says ST, "The magic of the HD 600s is their midrange—a purity of tone, especially when driven by tubes, that is quite special." Astonishingly transparent when driven in balanced mode by a HeadRoom BlockHead, found J-10 in July 2002. (Vol.21 No.2 WWW)

Shure KSE1500: $2999
Unlike other in-ear monitors, most of which have balanced-armature drive-units, Shure's KSE1500s use electrostatic drivers: In each monitor, a virtually massless diaphragm is suspended between two stators. Because diaphragms and stators alike are operated at high voltages, the Shures must be used with their companion amplifier (included in the $2999 price), which doubles as a DAC whose USB input accepts data from Macs and PCs, as well as from iOS and Android devices. Word lengths of 16, 24, and 32 bits are accepted, as are sampling rates of 44.1 and 96kHz. With their standard earpiece sleeves, the KSE1500s had a bit of trouble fitting JA's wider-than-average ear canals (happily, they're supplied with other sleeves, the largest of which did the trick), but the Shures had no trouble delighting him with their clear, weighty bass reproduction and the "superbly natural tonalities" of their reproduction of women's voices. His verdict: "Shure's KSE1500 is the finest-sounding in-ear monitor system I have experienced." (Vol.39 No.11 WWW)

Smyth Research Realiser A8 system: $2910 ★
Based on the Smyth Virtual Surround algorithm, the Realiser A8 subjects an audio signal to a DSP simulation of the hearing mechanisms needed for full spatial perception and then reproduces that signal through headphones, allowing users to effectively take the sounds of up to 64 different listening rooms wherever they go. The package includes the Realiser A8 processor box and power supply, the RC-1 remote control, a TU-1 Head Tracker, a TR-1 Head Tracker Reference, and two HTM-1 miniature in-ear microphones. The Realiser A8 provided the same balance and soundstaging as KR's main system, and allowed him to hear subtle differences between his Manhattan and Connecticut systems. "For the first time in my life, headphone listening was not only convincing but enjoyable," Kal marveled, adding "Class A all the way. Not only does the Realiser sound transparent as a headphone amplifier, it transforms headphone listening both in stereo and in multichannel." (Vol.33 No.11 WWW)

Sony Signature MDR-Z1R: $2299.99
An example of the sort of very-low-distortion headphone design that HR calls the studio sound aesthetic, the MDR-Z1Rs are part of Sony's new Signature line, alongside their Signature TA-ZH1ES DAC–headphone amp (also profiled in this edition of "Recommended Components"). They include Sony's latest 70mm drive-unit, which features a 30µm-thick magnesium dome surrounded by an edge-ringlet of aluminum-coated, liquid-crystal polymer. (Impedance is 64 ohms.) These are built into earpieces comprising outer domes of chromium-plated stainless-steel mesh and inner domes of "breathable" Japanese paper, the latter said to act as an acoustic filter to damp the drivers' back waves. Leather and sheepskin respectively cover the headband and earpads, and two cables are provided: a 3m single-ended cable fitted with a 3.5mm plug, and a 1m balanced cable with the special 4.4mm plug that mates with the Signature TA-ZH1ES, which HR used for "about a third of" his listening. Herb praised the MDR-Z1Rs as being not only "the most natural-fitting, fatigue-free" headphones he's ever used, but also, "by far, the most naturally transparent and open-sounding of any closed-back headphones I know." (Vol.40 No.6 WWW)

Sony Signature TA-ZH1ES: $2199.99
Inside the Signature TA-ZH1ES headphone amplifier is a DAC whose performance stretches all the way to 32-bit/768kHz PCM, plus native DSD up to 22.4MHz. But it's the Sony's outside—specifically, its front panel—that most shoppers will notice first: a row of six outputs, including three balanced (XLR4, 4.4mm JEITA, and separate left- and right-channel 3.5mm jacks) and two single-ended (6.3mm and 3.5mm). In his listening tests, HR found that the TA-ZH1ES "excelled at bass drive, boogie, and bounce," and sounded "darker but no less transparent than either the Linear Tube Audio microZOTL2.0 or Pass Labs HPA-1 headphone amps." He also praised the Sony for a "hypnotizing, deep-sea, looking-into-the-abyss spatial perspective that got darker and denser as it descended (or ascended) into infinite space." (Vol.40 No.6)

Thinksound On2: $199.99 $$$
Thinksound's original On1 headphones were praised in July 2014 by ST, who hates in-ear headphones and noise-canceling headphones of any sort, yet who described the closed-back On1s as "Bass-rich, full-bodied, nonfatiguing, comfortable to wear, [and] reasonably well isolating" in their passive, closed-back manner. The On1s have now been replaced by the On2s—which, like their predecessors, have over-ear enclosures machined from sapele, a mahogany-like wood, and earpads of memory foam (the modern pillow stuff) covered with faux leather. For the new model, Thinksound's 40mm drive-units have been enhanced, the plastic headband has a more durable faux-leather cover, the earpads have an improved sewn construction, and the price has been lowered: from $299.99 to $199.99. JA described the On2s' bass as a bit lightweight compared to that of his AudioQuest NightHawks, but he was "impressed by the natural-sounding mids and the clarity of the lows" from the Thinksound cans—which, he declared, he could listen to for "at least an hour without experiencing fatigue" or any physical discomforts. His conclusion: "With the Thinksound On2s priced at a penny under $200, I can confidently recommend them." (Vol.37 No.7, Vol.40 No.4 WWW)

Ultimate Ears 18 Pro Custom in-ear monitors: $1350 ★ (plus custom earmold fee)
The 18 Pro is a three-way, in-ear, custom-mold design with six balanced armatures: two each for the bass, midrange, and treble, the latter allowing the 18 Pro to have the most extended top end of any UE model. It combined clean, airy highs with a smooth, detailed midrange and deep, well-defined bass. "Its ability to play low frequencies at high levels with minimal distortion is unmatched by other in-ear 'phones, and the clarity and smoothness of its midrange is Class A," said JA. Its mid-treble might sound a little laid-back with headphone amplifiers having a high output impedance, however. Price includes personalized aluminum carrying case and cleaning tool, but does not include the custom earmold fee; optional Ambient feature allows some leakage of exterior sounds and adds $50. (Vol.33 No.12 WWW)

Woo Audio WA5 (2nd Gen): $5899
Described as a line-level integrated amplifier for headphones and loudspeakers (the latter must be able to get by on just 10Wpc into 8 ohms), the Woo WA5 uses, per channel, one 300B triode tube running in single-ended mode and driven by one 6SN7 dual-triode tube; a pair of 5U4G rectifier tubes straighten out the AC in this two-chassis, dual-mono, hand-wired design. Switches abound: for selecting between high and low output power, high- and low-impedance headphones, and headphones and loudspeakers. After harnessing the Woo to a variety of loads, HR declared it "a Darwinian step toward a new renaissance of audio humanism." It also sounds good—especially with less-sensitive, higher-impedance headphones such as Audeze's LCD-4s, which, according to Herb, the Woo drove "in a more satisfying fashion than any other headphone amplifier I've heard." After measuring the WA5, JA expressed reservations about its suitability as a driver of loudspeakers, but conceded that, for a single-ended amplifier, the Woo "performed better than I expected." (Vol.40 No.1 WWW)

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Apogee Electronics Groove: $295
After 30 years of designing and making pro-audio gear, Apogee has taken aim at the consumer market with the Groove USB DAC/headphone amplifier. Housed in a 3.7"-long aluminum case, the Groove uses an eight-channel ESS 32-bit Sabre DAC chip in a Quad Sum arrangement (four DACs per channel) for PCM input up to 24 bits and 192kHz. The Groove's (asynchronous) USB input is a Micro B socket, and its headphone output is a 1/8" jack; preceding the latter is a current-drive headphone amplifier—Apogee calls this Constant Current Drive—and a proprietary circuit that provides a variable output impedance, depending on the headphones used. Consequently, JI reviewed the Groove in combination with several different headphones (and in comparison with other DAC–headphone amps). Among the Groove's consistent strengths were its clarity and abundance of detail, which JI described while enjoying a Christy Moore track: "Through the Sennheiser HD600s, the Groove revealed every detail of Moore's great voice, each breath and reverb tail clear to the end." After conducting his measurements, JA concluded, "Overall, the Apogee Groove offers superb measured performance, which is even more impressive when you consider it costs less than $300!" (Vol.39 Nos.1 & 2 WWW)

Audeze EL-8: $699
Available in both closed- and open-back versions—HR reviewed the latter—the US-manufactured Audeze EL-8 uses planar-magnetic drivers, the diaphragms of which are made with voice-coil traces of varying thickness, intended to produce a more uniform driving force from center to edge. Audeze's acoustical Fazors, used in earlier models as response-smoothing waveguides, also appear in the EL-8. (HR suggests that the Fazor-equipped Audezes "sound more airy and transparent, but less weighty and punchy than the non-Fazor models.") Fresh from his time with Audeze's more expensive LCD-2 and LCD-X open-back 'phones, HR wrote that the EL-8s' "special beauty was their holistic way with space and inner detail," noting that, on one recording in particular, "the roof of my head became the dome of a cathedral." (Vol.38 No.12 WWW)

AudioQuest NightOwl Carbon: $699.99
According to HR, at the opposite end of the spectrum from Sony's MDR-Z1R headphones and their Apollonian studio sound aesthetic are AudioQuest's more Dionysian NightOwl Carbons, which use the same drivers as AQ's NightHawks, but in aperiodically vented rather than semi-open earpieces. (That driver is a 50mm biocellulose dome with a rubber surround.) The 99dB-sensitive, 25 ohm NightOwls also have the same "liquid wood" earcups, although here they sport not a faux-burled wood finish but dark-gray metalflake paint. How do the $699.99 NightOwl Carbons stack up against the $499.99 NightHawks? According to HR, "If you're one of those who thought the original NightHawks sounded too dark, you can now rejoice: properly broken-in, the NightOwls beguilingly straddled the lines between dark and light, hard and soft." Herb's conclusion: "If I were now forced to live with just one set of headphones, they would be AudioQuest's NightOwl Carbons." (Vol.40 No.6 WWW)

AudioQuest DragonFly Red: $199 $$$
AudioQuest DragonFly Black: $99 $$$
Descended from the company's popular DragonFly USB D/A headphone amplifier of 2012—a product whose price began as $249 before dropping, in 2014, to $149 with the release of the revised DragonFly v1.2—the new DragonFly Black and DragonFly Red embody a number of technical refinements. In particular, Black and Red alike use as their controller the Microchip PIC32MX, in place of the Texas Instruments TAS 1020B of their predecessors. That change allows the new AudioQuest DACs to use 77% less current than their forebears, which in turn makes them suitable for use with iPhones, iPads, and other portables. For the DragonFly Black, output voltage has now dropped from 1.8 to 1.2V, but in the DragonFly Red—which also has the distinction of an ESS Sabre 9016 DAC chip with 64-bit digital volume control—output voltage is bumped up to a healthy 2.1V, which AQ suggests better suits it to drive difficult headphone loads. (For use in driving the line-level input of a home playback system, both new DragonFlys require a cable with a 3.5mm stereo plug at one end and a stereo pair of male RCA plugs at the other.) AD remarked on the Black's greater openness and clarity over the original DragonFly, as well as its decreased bass weight, the latter associated with less boom with some recordings but less pleasant whomp with others. That said, AD wrote of preferring "the new DAC's superior musical incisiveness." The new Red, too, had less bass richness than the old DragonFly, but even "surer reproduction of pitches and timing." Yet when used with headphones, neither of the new DragonFlys was the least bit lacking in bass weight—and the Red's superior music-making was even more apparent. AD tried using the Black with his iPhone but, given the less-than-stellar sound, just didn't see the point—and surely wouldn't recommend buying the twice-as-expensive Red if use with a smartphone is all the consumer has in mind. After a false start occasioned by an unforeseen interaction between JA's test equipment and the Red's headphone amp, both DragonFlys generally acquitted themselves well on the test bench, though neither was at the head of the class in terms of jitter rejection. As of June 2017, the DragonFlies are MQA-capable. (Vol.39 No.9 WWW)

Koss ESP/950: $999.99 $$$
One night, after listening through the admirable Pass Labs HPA-1 headphone amplifier and Audeze LCD-4 headphones, HR decided that the sound was just a bit too uptown for the Jorma Kaukonen disc he was listening to, and switched to his new-old, "always-enjoyable" Koss ESP/950 headphones with matching E/90 Electrostatic Energizer power supply. He was "stunned by the richly textured midrange they delivered." As it turns out, the Koss ESP/950s can still be bought brand-new, which is a little like waking up from that dream where your favorite old car is in storage somewhere just around the corner—and finding out it's true. Herb: "Introduced in 1990—TJN reviewed them in the December 1992 Stereophile—the Koss ESP/950s are still in production, still made in Milwaukee, Wisconsin. They're exceptionally light (10oz or 284gm) and comfortable, and come with a limited lifetime guarantee: If they break or wear out, just send them back to Koss; when they return, they'll be good as new." The Kosses aren't the last word in bass or treble, but, as HR reminds us, "there's more to life than bass and treble: there's happiness and consciousness—and that's what the Koss ESP/950s delivered." (Vol.39 No.11 WWW)

Master & Dynamic MH40: $399
In the Master & Dynamic MH40, the earpads and the underside of the headband are covered in soft lambskin and the upper surface of the headband is made of cowhide. Nevertheless, democratic socialist (if not quite vegetarian) AD loved these 'phones, lavishing as much praise on their sound as on their comfort: "These Master & Dynamic headphones sounded clear and explicit—qualities they delivered in a manner that was smooth rather than brittle." AD also found the MH40s to be well balanced, with bass quantity in good proportion to their treble extension, and gave them extra points for their handy mute switch (which doubles as a right-channel indicator). (Vol.39 Nos.2 & 7 WWW)

Moon by Simaudio 230HAD: $1500
The compact (7" wide by 3" high by 11" deep) Moon 230HAD is described by HR as "a fusion product"—a space-saving mashup of DAC, headphone amplifier, and line-level preamplifier. It has four digital inputs, of which its USB input supports PCM up to 32-bit/384kHz and DSD up to 11.2MHz, and two analog inputs: a pair of RCA jacks on the rear and a 1/8" jack on the front, the latter for the analog output of a portable device. On its rear panel are two pairs of single-ended (RCA) line-level output jacks, one with fixed output and the other with variable output. When using the 230HAD as a DAC-line stage, HR described its sound as "an informative, no-nonsense transparency that told me more [about] how the recording was made." (By contrast, he described the Linear Tube Audio microZOTL's transparency as telling him "more about how the music was played.") At the end of the day, HR concluded that the Simaudio's strongest element was its headphone amp; when he used the 230HAD with a different manufacturer's DAC, music "sounded extremely sweet, beautifully detailed, and super lifelike. Totally top-of-the-top headphone sound." JA's measurements confirmed that, "as a headphone amplifier, the 230HAD offers superbly low distortion [and] very high dynamic range," but he was puzzled by apparent modulation of the noise floor during some tests of its DAC section. (Vol.39 No.9 WWW)

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Audioengine D3: $99 $$$ ★
The Chinese-built Audioengine D3, like the physically similar—and similarly portable—AudioQuest DragonFly, is a combination D/A converter and headphone amplifier with a USB standard A plug at one end and a three-conductor, 3.5mm mini-jack at the other. Its shiny aluminum case conceals an Asahi Kasei Microdevices AK4396 converter chip, a Texas Instruments LM49726 op-amp, and TI's popular TAS1020B USB receiver, with firmware for asynchronous streaming. Headphone users will delight in knowing that the Audioengine's price includes a 3.5mm-to-¼" jack adapter; those who wish to drive their audio systems with the D3's 2V RMS output must supply their own miniplug-to-RCA-plug cables. SM considered the D3, fresh out of the box, "too sharp on top"—even when he factored in the inherent top-end emphasis of the Skullcandy Aviator 'phones he was using. But the brightness moderated over time, "though not at the expense of [the D3's] intoxicating speed and vibrant high-frequency color." (Vol.37 No.4 WWW)

Grado SR60e: $79 $$$ ★
The original SR60 offered a rather dark-toned balance, with a full bass and excellent resolution of detail. A more forward midrange, however. Uncomfortable. Upgrades from the original SR60 include a new driver and improved cables. While maintaining the original's freedom from obvious colorations and resonances, the SR60i went a bit deeper in the bass and had a slightly more vivid midrange for a more involving overall sound. "The SR60i is modestly better than the original, and remains one of audio's great bargains," said Jim Austin. (Vol.17 Nos.6 & 10 WWW, original, Vol.33 No.4 WWW)

iFi nano iDSD LE: $129
A mere 16 years after the DSD format first appeared on the domestic-audio market, one can now buy a cigarette-pack–sized DSD DAC with an asynchronous USB input for just $189. That product, the iFi nano iDSD, includes a lithium-polymer battery that's automatically charged via the USB bus, and supports PCM resolutions up to 32-bit/384kHz. Used in a budget desktop system with a pair of Tannoy Reveal 402 active speakers, the iFi nano iDSD impressed ML with sound that was "rich and full, with a lovely dimensional quality—the last something that often goes missing from the sound of DACs in this price range." (Vol.38 No.9 WWW)

K

Audeze LCDi4, iSine20, and iSine10 in-ear monitors, HiFiMan Susvara headphones, Rogue RH5 headphone amplifier.

Deletions
Aurender Flow, Etymotic Research Custom-Fit earmolds, no longer available; AudioQuest NightHawk replaced by NightHawk Carbon; PSB M4U 2, Sennheiser HD 1, not auditioned in a long time.