Absolare Hybrid Stereo Power Amplifier: Signature Edition

When I walked into the Absolare room at the Munich High-End Show several years ago, I immediately thought I was hearing the very familiar sound of Absolare’s Passion preamplifier and Passion 845 power amplifiers driving Rockport loudspeakers. I had recently reviewed the Passion electronics (as well as the Rockport Altair and Lyra), and found the Absolare electronics to be extraordinarily musical. Both products are all-tube, ultra-minimalist designs executed with the world’s finest parts. The 52W SET monoblocks brought the ineffable musical immediacy of single-ended triodes to an amp that could drive real-world loudspeakers. The Passion series had a liquidity, warmth, and presence that are still vivid in my mind. 

But Absolare wasn’t featuring its all-tube electronics at this show. Rather, it was introducing the Hybrid monoblock amplifiers, which combine a tube input section with a transistor output stage. Yet the sound was so much like that of the all-tube Passion electronics that I did a double-take. Here’s what I wrote at the time: “Absolare always produces a great sound in Munich, but this year was its best sound yet with its new hybrid power amplifiers (tube input, solid-state output) driving Rockport Lyra speakers, with Absolare equipment racks and Echole cables. There was a complete lack of grain and glare; the presentation had utterly natural timbre and tremendous ability to pull me into the music rather than to think about the sound. A terrific system expertly set up.” Absolare’s room was also named “Best of Show” by several other reviewers.

The idea behind creating a hybrid amplifier was to preserve the tube electronics’ sonic signature in an amplifier that would drive a wider range of loudspeakers. Although the 52W Passion 845 drove the 94dB-sensitivity Magico Q7 Mk.II with relative ease, a zero-feedback SET is not the ideal match for lower-sensitivity speakers or for those with big impedance variations. To address this need, Absolare created a tube input stage, which provides nearly all the voltage gain, with a solid-state output section, which handles the current gain. 

Two years after the Hybrid monoblocks debuted, Absolare expanded on its tube/transistor formula to create the Hybrid Stereo power amplifier reviewed here. The Hybrid Stereo is based on the same circuitry and uses the same parts as the Hybrid monoblocks, but has fewer output transistors, less output power, and, of course, one chassis rather than two. I had for review the Signature Edition that features ultra-exotic component parts (see sidebar).

The Hybrid is housed in the now-familiar Absolare casework that looks nothing like that of conventional electronics. The relatively narrow and deep chassis eschews knobs and buttons, shiny aluminum faceplates, and an industrial aesthetic in favor of a sophisticated, leather-clad case that would look at home with the most upscale décor. You can choose from a wide range of leather colors and stitching. The two 12AU7 input tubes protrude proudly from the top of the chassis, with the heatsink for the solid-state output stage set behind them. The Hybrid is rated at 275Wpc into four ohms. The chassis rests on three elaborate vibration-isolating feet that are not attached to the chassis. These feet, used in custom versions throughout the Absolare line, are Absolare’s own design, made from aluminum and bronze. 

Around back, unbalanced inputs are provided on RCA jacks and balanced inputs on XLRs. The balanced inputs are transformer coupled. The speaker outputs are balanced, meaning that the negative terminal isn’t grounded (signal ground and chassis ground are separate). A rear-panel power-switch maintains the clean look as seen from the front. A single blue LED flashes upon turn-on, as the circuit powers up and stabilizes before the signal appears at the speaker terminals. Finally, a switch selects between high and low gain, useful for matching the Hybrid Stereo to a preamplifier or other source. 

Listening

I auditioned the Hybrid Stereo amplifier in my reference system, with an Echole Infinity power cord feeding it. After two weeks of auditioning, Absolare sent to me a 10′ pair of Echole Infinity loudspeaker cables. (Echole and Absolare are sister companies, and the internal wiring in the Hybrid uses the same custom metallurgy as the power cord and speaker cables.) Absolare was founded on the idea of system synergy, which is why Absolare created the cable company Echole, and why it makes its own hi-fi furniture.

Just as I (and others) heard in Munich, the Hybrid amplifier exhibited no hint of transistors. This was particularly apparent after putting the Hybrid Stereo in my familiar system for extended listening. In fact, it was as though the transistor output stage vanished, leaving the warmth, body, and liquidity of the tube input stage. The Hybrid sounded remarkably like the Passion 845 SET, but with deeper bass extension and greater dynamic authority. 

The Passion 845 SET’s midrange-centric character, with its powerful sense of presence through the midband that is the hallmark of the best SETs, was also the Hybrid’s defining quality. The midrange had a lush, velvety texture, with no hint of the thinning of tone colors that often characterizes transistor amplifiers. The Hybrid emphasized the fundamentals and lower-order harmonics of instruments, infusing the music with a warmth and density of timbre that were simply seductive. Dexter Gordon’s tenor on the beautiful ballad “I Guess I’ll Hang My Tears Out to Dry” from his 1962 album Go (Music Matters LP) was never reproduced with such a sense of tangibility, roundedness, and warmth. His instrument was utterly liquid, with no overlaying grain or hardness. In addition to nailing the timbre, the Hybrid also presented a wonderful sense of air and bloom around the instrument, furthering the impression of hearing music and not a recreation of it. The way this bloom expanded dynamically around the instrument, something Jonathan Valin calls “action,” was also remarkable. But as impressive as the Hybrid was sonically, it did something far more important emotionally—it revealed more expression and feeling in Gordon’s playing. Gordon puts his powerful, robust tone in the service of exquisitely delicate, tender, and expressive phrasing on this track. Through the Hybrid, the sensitivity of his performance had never before been rendered more vividly. Gordon made a practice of knowing and internalizing the lyrics to songs he played, which he felt gave him a deeper understanding of the song, something I could believe from the way he played this ballad, as reproduced by the Hybrid Stereo.

One of the most challenging aspects of characterizing an audio product through listening is drawing a connection between a specific sonic attribute and its musical effect. Some qualities are straight-forward—solid, tight, powerful bass often correlates with a sense of rhythmic drive, for example. But others are more ethereal. Take the Absolare’s reproduction of voice, particularly female voice. I heard a remarkable lifelike immediacy, heightening the singer’s emotion and expression. There was an intimacy that touched me deeply in a way that other amplifiers fall short of, no matter how clean, transparent, or detailed they may be. A few examples: Diana Krall’s moving version of the great Joni Mitchell song “A Case of You” from Live in Paris; Nora Jones’ Come Away With Me (MQA stream on Tidal); Joni Mitchell’s Blue (vinyl reissue); and Phoebe Snow’s debut album on Analog Productions’ 45rpm vinyl. I’ve heard all this music many times, but something about the Absolare’s reproduction of it breathed life and expression into the lyrics, the performances, and the heart of the song’s meaning.

A purchaser of the Hybrid Stereo can just enjoy this quality without thinking about it, but as a reviewer I was intrigued by why the Absolare conveyed more emotion and expression. I think several factors are involved. The first is the amplifier’s midrange immediacy, which tends to focus one’s attention on instruments in that frequency band. Vocals were projected slightly in front of the loudspeakers with startling presence. But I also heard a resolution of very fine detail in the voices, rich in subtleties of expression. The sound was human and lifelike, not flat and mechanical. Concomitantly, the Hybrid Stereo’s utterly organic and natural presentation put me in a frame of mind in which I was more receptive to musical meaning; the lack of electronic artifacts wasn’t a subliminal distraction reminding me that I was listening to an electro-mechanical recreation. 

I wouldn’t call the Hybrid Stereo a highly resolving amplifier in general. The tonal balance was darker and richer in color than many other solid-state amplifiers, favoring textural density over the last measure of resolution. The treble was less bright and open than that of many other amplifiers, with an ease and relaxation that encourages a focus on the music rather than on the sound. The Hybrid isn’t an amplifier you hear and say, “Listen to that detail!” Rather, it is one that keeps you glued to the listening seat in appreciation of the musical artistry before you. The resolution is more in the realm of subtleties of expression than emphases on high-frequency transients and sonic fireworks. This tube-like quality extended to the bass, with the Hybrid favoring warmth, fullness, and texture rather than slam and extension. As with voices, the Hybrid recreated a remarkable tangibility to acoustic and electric bass, and other instruments such as Bob Mintzer’s extended bass clarinet solo on “El Faquir” from the Steve Khan album Borrowed Time. The Absolare beautifully conveyed the dark chocolate richness of that wonderful-sounding instrument.

Finally, the Hybrid had no trouble driving the Wilson Audio Chronosonic XVX to satisfying levels. This speaker has a nominal impedance of 4 ohms, but the impedance falls below 3 ohms over much of the band, dropping to a minimum of 1.5 ohms. Despite this difficult load, the Hybrid maintained its composure at high playback levels: The soundstage didn’t collapse on peaks; the timbre remained liquid; and the bass fairly extended. 

Conclusion

The Absolare Hybrid Stereo amplifier successfully achieves its design goal of bringing the many virtues of single-ended triode amplification to a product that can easily drive a wide variety of loudspeakers. Indeed, it drove the demanding Wilson Chronosonic XVX with aplomb. Amazingly, there was no hint of transistors in the Hybrid’s sound; it has astonishing liquidity of timbre, is utterly grain-free, and projects a sense of presence that sounds very much like the best SET amplifiers. The Hybrid creates a directness of musical expression—of hearing nothing between you and the music—that is unique among solid-state amps, in my experience. That directness of expression fosters an intimacy with the music and performers that is seductive. The Hybrid goes beyond “hi-fi” to mediate a deep connection with musical meaning in a way that defies sonic analysis. Can you buy a more “resolving” amplifier for the money? Or one with deeper bass extension and “slam.” Yes, but no other amplifier short of an SET delivers the emotion of music like the Absolare Hybrid Stereo.

Specs & Pricing

Type: Dual-mono hybrid tube/solid-state stereo power amplifier
Power output: 275Wpc (4 ohms)
Inputs: Unbalanced on RCA jacks, balanced on XLR jacks
Gain: 23dB or 29dB, user selectable
Tube complement: 2x 12AU7 or 12BH7, select NOS tubes
Bandwidth: 20Hz–20kHz ±0.2dB, 15Hz–30kHz ±1dB
Input impedance: 10k ohms unbalanced, 20k ohms balanced
Input sensitivity: 1.2V (high-gain setting); 2.4V (low-gain setting)
Compatible speaker impedance: 4–8 ohms
Dimensions: 15″ x 7.9″ x 25.5″
Weight: 73 lbs. net
Price: $52,000

ABSOLARE USA LLC
40 Pemberton Road
Nashua, NH 03063
(917) 535-8888
info@absolare.com