Woo Audio

WA24 20th Anniversary Edition Headphone Amplifier

The Woo Audio WA24 20th Anniversary Edition is a reference-level, single-ended Class A vacuum-tube headphone amplifier with zero-feedback operation and point-to-point wiring. Its circuit uses four custom-made 3A/109E direct-heated triodes in parallel, an in-house STEP-UP Driver transformer with a nano-crystalline core, and oversized output transformers, housed in a two-tier CNC-machined aluminum chassis with a separate linear power supply. It provides XLR and RCA inputs, balanced 4-pin XLR and 4.4mm Pentaconn outputs, and unbalanced 6.3mm and 3.5mm outputs, with a 10Hz–40kHz frequency response and compatibility with headphones rated from 8–600 ohms.