Over the past several years Dr. Alex Cavalli, a gifted consulting physicist and engineer, has been quietly developing some of the most ambitious and best-sounding headphone amplifiers on the market today. First came the hybrid tube/solid-state Liquid Fire headphone amplifier, which TAS owner Tom Martin termed a “state of the art product” (a judgment neither he nor I would make lightly). Next came the Liquid Lightning electrostatic headphone amp, which I described as “arguably the most honest and revealing amplifier that money can buy for purposes of powering electrostatic headphones.” More recently, I reviewed Cavalli’s tube-roller-friendly Liquid Glass amplifier in our sister publication, Hi-Fi+, where I called it “a terrifically open-minded product, which offers as many uniquely beautiful sonic ‘realities’ as there are tube sets to audition.” This brings us, finally, to Cavalli’s new Liquid Gold solid-state headphone amplifier (priced at $6450). Cavalli claims the Liquid Gold is his most sophisticated and best-sounding design to date—one that builds upon all the positive attributes of his earlier works.
Before we delve deep into a discussion of the Liquid Gold’s sound, let’s take a brief moment to review its basic features, functions, and technological details. The Liquid Gold is a very powerful, “statement-class,” fully differential, balanced-output, solid-state headphone amplifier. Cavalli has this to say about the Liquid Gold’s circuit design: “Its fully differential topology takes advantage of all the benefits of differential operation, including high common mode noise rejection. The differential circuit design of the Liquid Gold distinguishes it from some other balanced amplifiers, which operate two separate channels connected together (bridged) at their outputs.”
The unit provides three analog inputs (one single-ended and two balanced) plus four outputs (two single-ended via TRS-type jacks and two balanced via a 4-pin XLR jack and a left/right pair of 3-pin XLR jacks). To accommodate headphones of differing levels of sensitivity, the amp provides two switch-selectable gain settings: Hi (8x or 18dB of gain) and Lo (4x or 12dB of gain). Moreover, one of the two TRS jacks (Jack 1) is fitted with gain-reduction resistors that enable the amp to be used with (most) ultra-high-sensitivity headphones.
The Liquid Gold is fitted, as are all Cavalli amps, with a piezo-electric power switch said to enhance long-term reliability (picture an ultra-reliable cross between a traditional push-button switch and a touch-sensitive switch and you’ve got the general idea). Once the power switch is activated, the amp commences a “controlled startup sequence to protect the output devices and their drivers from high startup currents.” On startup an LED labeled “W” (for “Wait”) illuminates in red as the amp goes through a gradual one-to-two minute power-up sequence. Once the “W” lamp turns white (indicating that the initial waiting period is complete) a second LED labeled “H” (for “Headphones”) illuminates in red as various sensing circuits “wait until the DC offsets at the outputs have stabilized to the point where no damage to headphones can occur.” Only then will the “H” light turn white, indicating the amp is ready to play.
Judging by the sound it produces the Liquid Gold has been designed with a handful of sonic objectives in mind, including: dead-neutral tonal balance, low distortion, wide bandwidth, exceptional resolution, and terrific transient speed. Put these together and you get one of the most (if not the most) disarmingly honest and revealing headphone amplifiers I’ve yet heard. Put on a piece of music you think know well, and odds are that within seconds the Liquid Gold will have you asking yourself, “My word, where did all that additional musical information come from?” The effect is uplifting and invigorating in the extreme, but also a little unnerving in that you realize much of what you thought you knew about favorite recordings suddenly seems woefully incomplete. In an instant, you learn there is much more to hear than you might once have supposed.
In this respect, the Liquid Gold’s sonic virtues closely parallel those of another state-of-the-art product, namely, the Abyss AB-1266 planar-magnetic headphone reviewed in this issue. Dr. Cavalli is keenly aware of Joe Skubinski’s impressive Abyss headphones and likewise Mr. Skubinski is appreciative of Cavalli’s Liquid Gold amplifier. Both men, in fact, recommend and endorse one another’s products. My personal experience has been that one really hasn’t heard all that the Abyss headphones have to offer until one hears them driven by the Liquid Gold, and vice versa. For this reason, I used a set of Abyss AB-1226 ’phones for much of my review listening, although I also used other top-tier ’phones such as the Audeze LCD-3 and HiFiMAN HE-6.