AXPONA 2024

Rich Pinto of Treehaus Audiolab, which is based in Southport, Connecticut, has been dedicated to developing SET amplifiers and high-efficiency speakers since 2017. Here at AXPONA, he introduces the A/Machines monoblock amplifiers ($39,000/pair), which showcase his commitment to classic design, in the sound and the aesthetics.

Engineered and built by Radu Tarta (of simplepleasuretubeamps), the 6Wpc A/Machines consists of a 10Y/801A tube driving a Western Electric 300B though a Finemet-Core interstage transformer made in Japan for Treehaus Audiolab. The output transformer, also with a Finemet-Core, utilizes a “non-traditional impedance loading which eliminates the typical darker, syrupy sound of most 300B designs,” Treehaus says. Coleman filament regulators on separate DC supplies provide heater current to the directly heated tubes.

A pair of A/Machines power amplifiers uses four enclosures: each channel has an amplification chassis and a power supply chassis. "To keep it simple, we doubled the total tube-rectified power supply capacity compared to the existing design. Gratuitously, we utilized Finemet-Core chokes and massive G.O.S.S. Core power transformers. MIL-spec Amphenol umbilical cords and Cardas binding posts connect power and signal."

The A/Machines amps employ Simpson analog gauges, 6mm aluminum plinths, crinkle powdercoat enclosures, and brass detailing. A matching Treehaus Audiolab The A/Machines Preamplifier, which literally goes to 11 ($19,000), also in crinkle powdercoat finish, covers "the design language on our existing preamplifier electronics."

In the same room, an SME Model 12 MkII Turntable, SME 309 Tonearm, Ortofon MC Verismo Cart, dCS Rossini APEX DAC, Treehaus AudioLab “Phantom of Luxury” Field-Coil loudspeakers($29,000/pair), Ken Tanaka LCR Phono Stage, Purifi class-D woofer amplifiers, MiniDSP Active Crossover/EQ for woofers, PS Audio P3 Power Conditioner, and Iconoclast cabling, including UPOCC RCA interconnects, TPC Generation 1 and Generation 2 speaker cables, and BAV power cables.

The Treehaus Audiolab system wasn't just a fine sound system; it was a visual spectacle. Four amplifier casings gleamed alongside the colossal open-baffle speakers, their "Walnut Cookies" finish a swirl of wood tones. The sound embodied the essence of classic 300B: warm bloom, crystal-clear transparency. Midtones were clear, while the treble seemed to extend into the bright Chicago sky. Radiohead's "Weird Fishes," from an In Rainbows LP, spread, grew, and filled the room like a benevolent audiophile octopus.