Twochannel Reference Build — Neutral Ported Boulder Reference

For the owner who wants the recording delivered without a house sound, in a dedicated room where a 4-ohm Wilson can be driven hard and set clear of the wall. The Boulder's current and the dCS converter's accuracy define the system while the Aurender simply feeds them bits. It suits an owner who ranks measured transparency above warmth.

The Wilson Sabrina X is a compact three-way whose neutrality comes less from its drivers than from what surrounds them. Its 8-inch woofer, midrange, and 1-inch dome are mounted on a stepped baffle that time-aligns their outputs at the listening seat, and they sit in a cabinet of Wilson's damped composite that rings far less than the MDF norm, so the box adds little voice of its own to the sound passing through it. A rear port tunes in-room bass to about 31 Hz. The load it presents, 4 ohms nominal at 87 dB sensitivity, is less difficult than it is demanding: it rewards an amplifier that can pour current without its character shifting as it does so. The Boulder 1060 is built around that idea to an unusual degree. It produces 300 watts into 8 ohms and 800 into the Sabrina X's 4-ohm load, stays stable down to 2 ohms, and does so while measuring 0.001 percent distortion and a 127 dB signal-to-noise ratio. Those numbers are the point: Boulder designs for the absence of a signature, so the amplifier's task is to multiply the signal and add nothing audible to it. Its output rising from 300 watts at 8 ohms to 800 at 4 means the Wilson's woofer is gripped just as firmly in the bass, where it pulls the most current, as the tweeter is up top. The digital end is two boxes and no preamplifier. The Aurender N100H holds and serves the music from a wired network, passing it over S/PDIF to the dCS Delius, whose Ring DAC converts and whose own volume control, running in the digital domain at a 6-volt output into the Boulder's 50-kilohm input, sets level without a separate analog gain stage in the path. Leaving the preamplifier out is a neutrality choice as much as a simplicity one: with the Boulder's noise floor already 127 dB down, the fewer active stages the signal crosses, the less chance anything tints it before the speaker. The neutrality here is cumulative. A cabinet that stays quiet, an amplifier engineered for the absence of a sound of its own, and a converter whose accuracy is its entire design brief all withhold any editorializing, so what the listener hears tracks what was recorded. The interface that carries the design is the Boulder into the Wilson: the Sabrina X's 4-ohm impedance and modest sensitivity would expose an amplifier that softened or ran short of current, letting the bass blur and the images lose their edges. The Boulder's 800 watts and vanishing distortion are what keep the presentation honest from top to bottom.

A system this transparent has the vices of its virtues. The Sabrina X and the Boulder hide nothing, so bright, compressed, or poorly balanced recordings are handed over with their flaws intact rather than smoothed into listenability. The rear port reaches a genuine 31 Hz but wants breathing room behind the cabinet; pushed close to a wall it thickens, and the octave below 31 Hz still calls for a subwoofer on large-scale material. The Boulder runs hot and heavy, over 60 kilograms of amplifier that pulls real idle power and needs a substantial rack and ventilation. And the preamp-less chain, pure as it is, routes every source through the dCS; there is no analog input here for a turntable without adding a phono stage and a way to sum it in.

• 01

  Swap Sabrina X → A3 (−$5,200)

  The Magico A3 substitutes a sealed, aluminum-cabinet three-way for the Wilson's ported enclosure, trading a little in-room bass weight for an even lower-coloration box and a gentler, more room-friendly low-end roll-off. It is a lateral move in neutrality with a different bass character and easier near-wall placement.

• 02

  Swap 1060 → X250.8 (+$3,551)

  The Pass X250.8 keeps the neutral intent but adds first-watt Class A operation, giving a slightly warmer, denser tone than the Boulder's clinical transparency while still commanding the Wilson's 4-ohm load, at the cost of more heat and a higher price.