Ayre KX-R TwentyRecommended Reference ComponentThe original Ayre Acoustics KX-R preamplifier was reviewed by Pete Roth for SoundStage! Ultra in December 2010, and was named a Recommended Reference Component here in March 2011. Pete ended up buying the review sample. Last month, in Ultra, Jeff Fritz reviewed the KX-R’s successor, the KX-R Twenty, which this month is added to the same list. Jeff, like Pete, owned a KX-R, and said of it in his review, “It might be the single best stereo component I’ve ever owned.”

Read more: Recommended Reference Component: Ayre Acoustics KX-R Twenty Preamplifier

Audeze LCD-XRecommended Reference ComponentOn March 1, SoundStage! Xperience published Garrett Hongo’s review of Audeze’s LCD-3 headphones, which he thought worthy of a Reviewers’ Choice award. Based on the strength of that review, last month we added the LCD-3s to our Recommended Reference Components list. About two-and-a-half months later, Xperience published S. Andrea Sundaram’s review of Audeze’s LCD-X headphones, which also received a Reviewers’ Choice award -- and this month, we name the LCD-Xes a Recommended Reference Component.

The LCD-3 and LCD-X headphones use planar-magnetic drivers -- a hallmark of Audeze ’phones -- and are more or less identical in size, shape, and weight. But there are some differences, including in price: the LCD-3s retail for $1945, the LCD-Xes for $1699. The most visible difference is in the earcups -- the LCD-3s’ cups are of Zebrano wood, while black-anodized aluminum is used for the LCD-Xes.

Things differ somewhat inside as well. Brent Butterworth’s measurements of the two models, which accompany the reviews, reveal comparable frequency responses throughout the audioband; in other words, the two models’ tonal balances should be similar. The measured distortion of both sets of ’phones was negligible at SPLs of 100dB, which means both should sound superclean. But the impedances differed: 47 ohms for the LCD-3s vs. 22 ohms for the LCD-Xes. Most noteworthy was the LCD-Xes’ far higher sensitivity -- 101.5dB vs. 94.5dB for the LCD-3s -- which Brent said was “very high for planar-magnetic headphones.”

Read more: Recommended Reference Component: Audeze LCD-X Headphones

Esoteric C-02Recommended Reference ComponentEsoteric, the high-end division of TEAC, is best known for its digital products: transports, DACs, clocks, and disc players. But Esoteric’s product line is broader and more accomplished -- they also make outstanding amplifiers and preamplifiers (and, at one time, made speakers), including the top-of-the-line Master Sound Works C-02 preamplifier, which Howard Kneller reviewed for SoundStage! Ultra in February and described as “transcendent.” The C-02 retails for $24,750 USD without phono stage, $26,500 with (Howard reviewed the former).

Most preamps are fairly light, but the C-02, which measures 17.4”W x 6.3”H x 17.8”D and features stunning aluminum casework, weighs 71 pounds. Howard described its size and weight as “power-amp-like” and the quality of its casework as “museum-worthy.”

Read more: Recommended Reference Component: Esoteric Master Sound Works C-02 Preamplifier

Audeze LCD-3Recommended Reference ComponentAudeze LLC, based in Fountain Valley, California, is a relative newcomer to high-end headphones, yet has quickly become a darling among audiophiles. Audeze debuted its first headphone model, the LCD-1, in 2009. Apparently, it was enough of a success that the company’s designers immediately went to work on the LCD-2 ($1145 USD), which they still produce today. Now the Audeze roster includes three more headphone models, including the most expensive, the striking-looking LCD-3 ($1945), which Garrett Hongo reviewed for SoundStage! Xperience in March 2014.

One of the things that has likely contributed to Audeze’s success, and the distinctive sound that their headphones have become known for, is their use of planar-magnetic drivers instead of the dynamic drivers found in most headphones. As Garrett explained in his review, the claimed benefits of planar-magnetic drivers include “faster, more coherent sound than a cone because the diaphragm moves ‘as one’ rather than, like a cone, beginning from the center outward, which makes cones more susceptible to breakup at higher frequencies. In addition, since the Audeze driver is so large, the excursion it needs to move a given amount of air is far less than a conventional cone would need -- which also, in theory, should result in less distortion.”

Read more: Recommended Reference Component: Audeze LCD-3 Headphones

Joseph Audio PulsarsRecommended Reference ComponentUsually, the speakers we name as Recommended Reference Components are large three- or more-way floorstanding models capable of reproducing bass that reaches or approaches 20Hz. Such low-end depth is necessary to reproduce the full range of audible frequencies (aka the audioband), which extend from 20Hz to 20kHz. But sometimes we review small speakers that, despite not being able to reproduce the bottom octave -- or even the bottom two octaves -- still deserve recommendation for their exemplary performance above that range. Such a loudspeaker is the Joseph Audio Pulsar, a two-way, stand-mounted design that sells for $7700 USD per pair.

When Graham Abbott reviewed the Pulsar in January, he dealt with the issue of bass right away. He heard the usual limitations of small speakers, but also some surprising strengths: “Tosca’s Delhi9 (CD, G Stone K-7) has some very deep bass and bass tones that the Pulsars admirably reproduced, trading off the very lowest frequencies for a rhythmic, resonant underpinning that refused to weigh the music down. The Pulsars couldn’t replace the bass reach and solidity of a high-end floorstander, but they might fool you into thinking you’re close.

Read more: Recommended Reference Component: Joseph Audio Pulsar Loudspeakers