2018 Products of the Year: Amplifiers

Equipment report
Solid-state power amplifiers,
Tubed power amplifiers,
Integrated amplifiers
Audio Research REF 750 SE,
Boulder Amplifiers 1160,
CH Precision I1,
Constellation Inspiration 1.0,
Dynaco ST-70 Series 3,
Pass Laboratories XA25
2018 Products of the Year: Amplifiers

Integrated Amplifiers of the Year

Constellation Inspiration Integrated 1.0
The firm’s most affordable effort and the third entry in Constellation’s Inspiration Series, the 100Wpc Integrated 1.0 has the sonic character of a “control” amp in the most exacting and incisive sense of the word. Leaving nothing unexplored, it latches onto an audio signal with a death grip, not letting go until it reveals and resolves every sliver and shred of the program material. Its general tonal signature is dead-on neutral, its personality ever-so-slightly shaded to the cooler side of the spectrum, as befits a solid-state amp that doesn’t give an inch to suppress dynamics, or soften transients, or cop out under high-stress bass demands. Treble performance is equally exacting but open, with hints of air and sweetness and not a trace of grain. Visually streamlined but unmistakably Constellation in its elegant, matte-finish aluminum casework and distinctive cross-drilled side panels, the Inspiration 1.0 is nothing short of a new high for Constellation’s entry level.

CH Precision I1 Universal
$38,000–$50,000, depending on configuration
Though dubbed an integrated amplifier, CH Precision’s I1 barely resembles typical members of that ilk. Its modular nature allows users to configure it to handle virtually any combination of digital inputs, analog inputs, streaming audio, and even a moving-coil cartridge. Moreover, the I1’s sound quality is every bit as sonically and musically revelatory as that of far more expensive CH standalone components, several of which it incorporates virtually intact. Dynamics, in particular, are extraordinary, and the excellent phono card obviates the need for an external phonostage. How CH Precision got so much of its “secret sauce” into the I1 at less than half the price of the contributing separates is difficult to fathom, but that’s exactly what the Swiss company did. Overall, it’s hard to think of another $50k electronics choice—either integrated or separates—that boasts the same pedigree, versatility, footprint, value proposition, and sonics as the I1.

Tube Power Amplifiers of the Year

Dynaco ST-70 Series 3
The new ST-70 was obviously not intended to be an exact copy of the original, but rather aims to considerably raise the sonic bar compared to what was expected in the early days of stereophonic sound. Development was driven by the notion of what David Hafler would do today, given modern components and available tubes. The Series 3 captures what is good about vintage tube sound while dodging its weak spots. Harmonic textures are consistently sweet and refined without sounding overly liquid. Tonal balance is reminiscent of the Quad 57 ESL, offering a middle-of-the-hall perspective. Transient decay is accommodated by an impressively low noise floor. The Series 3 maintains the sonic soul and virtues of the original ST-70 while injecting a dose of steroids into the mix. The ability to resolve individual threads in a complex passage is highly evolved. The bass range is much improved. And detail resolution and microdynamic intensity are significantly sharpened. This is an amp that David Hafler would most definitely have been proud of.

Audio Research Corporation REF 750 SE
$33,000 each; $66,000 per pair
For many music lovers, these massive amplifiers will be the final word in driving any full-range loudspeaker. You would expect effortless power from an amplifier sporting 16 KT150 output tubes generating 750W of output power, and that is exactly what you get. Even with difficult-to-drive loudspeakers, there is an ease of presentation and lack of compression that opens a new level of realism for all musical material. The real beauty of these amplifiers, though, is their utter transparency and faithfulness to the source. Instruments and voices are portrayed with fullness, body, and life-like realism, without addition or subtraction. But perhaps the most surprising feature of the 750 SEs is the finesse and delicacy they offer on relatively simple musical material (such as piano and cello duos), even at low listening levels—not unlike what you would expect from 300B single-ended amps. The cost is substantial but certainly competitive with other elite amplifiers. Downsides: heat (air conditioning is probably a must) and periodic tube maintenance (made easier by the built-in meters). But if you value natural and effortless music reproduction above all else, the REF 750 SEs are truly satisfying.

Solid-State Power Amplifiers of the Year

Pass Labs XA25
The XA25 amp is among Pass Labs’ most humble efforts to date—at least outwardly. And users will admittedly need to be a little respectful about speaker selection, since this solid-stater is rated at a mere 25Wpc into 8 ohms. But hold the phone; this wattage is delivered courtesy of Pass’ Class A design. So buckle up and prepare to luxuriate in pure liquid musicality. Pass gear often suggests sweetness and warmth, but the XA25 takes these qualities a luminous step further. Images are conveyed with a weightier sense of physicality—a visceral feeling of mass. Simply listening to a solo piano through the XA25 reveals heretofore unheard shifts in the micro-dynamics of the player’s keyboard touch. Beyond the extraordinary resolution engraved in the XA25’s personality is an ability to transform a listening space into a three-dimensional tableau of images and ambience. A magical amp.

Boulder Amplifiers 1160
Benefitting from design and build improvements developed for Boulder’s two higher tiers (the 2100 and 3000 lines), the all-new 1160 is significantly better than the amplifier it replaces in every way. The network-connected 1160 incorporates advanced features including the ability to self-diagnose any faults and report them to the factory for quick repair. The output section is identical in parts and design to that of the 2100 series amplifiers but with less power. Nonetheless, the 1160 can effortlessly deliver a massive amount of clean wattage in ways that make the Boulder sound more powerful than similarly rated competition. It handles deep bass transients with aplomb, providing lifelike dynamics and the ability to control loudspeakers. The bass is tight and fast, in contrast with that of some other amplifiers, which may sound warmer at the cost of low-end definition. The 1160’s “voicing” reveals the music rather than colors it, and this makes the amp (along with the matching 1110 preamplifier, which also received a Product of the Year Award) a remarkably good core component for building a truly excellent system.