ETA Audio ULI AlNiCo Open-Back Headphone

ETA Audio's ULI is the first headphone built around an AlNiCo magnet motor, the same alloy prized in vintage JBL, Altec, and Tannoy loudspeakers for its sweet decay and low distortion. Hand-assembled in New York around an eighth-generation Purple driver, ULI is ETA's flagship and the most ambitious open-back dynamic design they have built to date. Each unit is made to order with a lead time of approximately six weeks.

Type and Technology

Over-ear, open-back, dynamic. The Purple driver is ETA's eighth-generation transducer and the first in headphone history built around an AlNiCo magnetic motor rather than conventional neodymium. A 50mm biocellulose diaphragm, just 7 microns thick with a 5 micron ribbed PET suspension, rides on a silver-copper alloy underhung voice coil inside an anodized purple driver frame. The long-gap, short-coil geometry, more common in high-end loudspeakers than headphones, keeps the coil fully within the magnetic field for better transient response and linearity. At 16 ohms and 81 dB/mW sensitivity, ULI is efficient enough to run well off modest sources despite its flagship ambitions.

Sound Character

AlNiCo trades some of neodymium's raw power for a sweeter decay, lower distortion, and higher efficiency, and ULI leans into that character rather than chasing sheer output. Early hands-on coverage from CanJam and HiFiCON has drawn comparisons to established reference-tier headphones, with reviewers pointing to a spacious, laminar presentation that avoids the resonant peaks and turbulence common to more conventional open-back designs. Expect texture and timbre first, a smooth and unforced top end in the tradition of AlNiCo-loaded vintage loudspeakers, backed by the control of an oversized eighth-generation motor system.

Build and Comfort

The body is fused nylon, 3D-printed using HP's Multi Jet Fusion process for shell geometry that traditional molding cannot replicate, paired with a 316 stainless steel headband and a rear-bias suspension mounting system. An elastic polymer suspension strap distributes clamping force across the head, and the earcups use a pair of oversized Ink earpads developed with ZMF, at 145 x 125 x 30mm, ETA's largest pad to date. All-in weight stays under 500 grams despite the fully open chassis.

Best For

Listeners chasing a genuinely different flagship sound rather than another neodymium planar or conventionally tuned dynamic. ULI suits anyone building a reference desktop rig around texture, timbre, and soundstage over raw slam, and collectors drawn to a hand-assembled, small-batch build with real engineering behind the story.

What's in the Box

• ETA Audio ULI headphone
• 2 Ink earpads (145mm x 125mm x 30mm)
• Stock cable, terminated per order (6.35mm, XLR 4-pin, or 4.4mm balanced)
• Pelican hard shell case with molded foam
• Owner's card
• Information booklet

Specifications

What Reviewers Say

ULI drew significant attention at HiFiCON 2025 and CanJam ahead of launch, with early coverage calling out its AlNiCo motor as one of the most distinctive engineering stories in recent headphone releases. ETA's own product page features hands-on video coverage from HiFiCON, embedded below.