Woo Audio WA23 Luna

The Woo Audio WA23 Luna is a single-ended, all-tube Class A headphone amplifier and preamplifier that takes Woo's flagship WA33 architecture and distills it into a more compact form, housed in a CNC-machined solid aluminum chassis with a striking black-and-gold aesthetic, Mundorf Supreme Silver/Gold capacitors, an ALPS RK50 potentiometer, 2A3 power tubes, and the transformer-coupled, point-to-point wiring that defines Woo's reference tier. Designed and assembled in New York.

Type and Technology

Single-ended all-tube Class A headphone amplifier and preamplifier. Transformer-coupled, point-to-point wired circuit assembled by master craftsmen by hand. Tube complement: 2x 6C45 driver tubes, 2x 2A3 power tubes, 1x 5U4G rectifier tube, self-biasing. PTFE tube sockets. Mundorf Supreme Silver/Gold interstage coupling capacitors (4 per channel) and Mundorf MTube voltage filter capacitors (3). ALPS RK50 potentiometer, one of the finest volume controls in audio, housed in a custom brass enclosure. Compatible headphones: 8 to 600 ohms. Selectable Hi/Lo impedance and Hi/Lo level for headphone. Selectable preamplifier or headphone output mode. Analog inputs: XLR balanced x1, RCA x2. Headphone outputs: 4-pin XLR balanced and 6.35mm single-ended. Preamplifier output: XLR balanced. External power supply unit connected via a 1.0m custom umbilical cord for clean DC separation from the amplifier chassis. Power consumption: 150W. Designed and assembled in New York. Three-year limited warranty.

Sound Character

Rich, detailed, and dynamically alive, the 2A3 power tube is one of the most beloved triodes in audio, combining low-distortion single-ended operation with a tonal naturalness and warmth that larger output tubes often lack. The Mundorf Silver/Gold coupling capacitors add air and extension without brightness. The transformer coupling provides the physical weight and control that distinguishes a well-designed output transformer amp from more affordable tube designs. Wide dynamic range, deep full bass, clean highs, and rich inner detail make the WA23 Luna an immersive and revealing listening partner.

Build and Finish

CNC-machined from a single solid block of aluminum in an anodized, sand-blasted finish. Black-and-gold colorway. Amplifier dimensions (without tubes): 16" L x 10.625" W x 4" H; (with tubes installed): 16" L x 10.625" W x 7" H. External PSU: 7" L x 4.125" W x 3.25" H. 30 lbs combined weight. Designed and assembled in New York.

Best For

Audiophiles who want a reference-tier single-ended tube amplifier with premium passive components, exceptional build quality, and the tonal character of 2A3 power tubes in a chassis that reflects the craftsmanship of the electronics inside.

What's in the Box

• Woo Audio WA23 Luna headphone amplifier/preamplifier
• 6C45 driver tubes (x2)
• 2A3 power tubes (x2)
• 5U4G rectifier tube (x1)
• External linear power supply unit
• 1.0m premium umbilical cable
• Quick start guide

Specifications

What Reviewers Say

Currawong puts the WA23 Luna through its paces, calling it an absolute beast of a tube headphone amplifier with the power and refinement to match its striking design.