Kiss on Wood, Rachel Yonan, viola; Kwan Yi, piano.; Shostakovich: Piano Concerti 1–2; Piano Works, Yuja Wang, piano; Boston Symphony/Andris Nelson; Begin The Song! A Purcell Academy, Paul-Antoine Bénos-Djian, countertenor; Le Consort; Chopin: 24 Préludes; Sonata 2, Emil Gryesten, piano.

Adam O'Farrill: For These Streets; Billy Mohler: The Eternal; Louis Stewart/Jim Hall: The Dublin Concert; Denny Zeitlin: With a Song in My Heart.

Goose: Everything Must Go; Mark Pritchard & Thom Yorke: Tall Tales; Sons Of The East: SONS; Hayden Pedigo: I'll Be Waving As You Drive Away.

Imagine navigating the hectic rooms of an audio show at which a sea of similar-looking, similar-sounding gear blends into a predictable thrum, drawing a chorus of familiar nods. Then you stumble into the room occupied by Rich Pinto and his Treehaus Audiolab components. Here, the expected evaporates, replaced by designs that offer something different, both inside and out, sparking curiosity among jaded journalists and seasoned listeners.

Most audio engineers split hairs. Eelco Grimm splits microseconds. His expertise in high-precision audio laid the groundwork for Grimm Audio, the Dutch venture he cofounded in 2004 with fellow electrical engineer Guido Tent. The company's master clocks and DACs, developed for both the pro audio and home hi-fi markets, combat tiny timing errors and jitter that can blight digital audio.

I'd been building and repairing tube amplifiers for a few years when my first Altec A5 Voice of the Theater speakers arrived. I bought them to help me evaluate the sound of low-powered triode amps—but whoa! The moment I turned that VOT system on, I heard from 30' away the sound of either a waterfall or a large AM radio tuned between stations . . . What's the best tube tester? A 107dB/watt speaker!