Woo Audio

WA33 (2nd gen) Fully-balanced Headphone Amplifier

Introduced 2017$9,999 MSRP

The WA33 is Woo Audio's flagship fully-balanced, push-pull, Class-A tube headphone amplifier/preamplifier, using a proprietary "Internal Coupling Architecture" that permanently joins the amplifier and power-supply sections into a single two-chassis unit without an external umbilical cable ([Hi-Fi+ review](https://hifiplus.com/articles/woo-audio-wa33-headphone-amp-preamplifier/), [Audio Advisor product listing](https://www.audioadvisor.com/prnt-wa33e-blk)). It drives a quad of 6C45 driver tubes into a quad of 2A3 power tubes in direct-heated triode configuration, delivering up to 10 watts per channel — a substantial output for a headphone amp — and since its 2025 second-generation update it also offers a dedicated current-drive mode for Woo's "True Ribbon" headphones.

MSRP

$9,999

Used market · Good

$7,250

-27% vs MSRP

as of Sep 1, 2026

Sell or trade this Add to my system

MSRP to used market

From $9,999 at launch to $7,250 today.

Specifications

Price: $7,999 base (Standard); $14,999 (Elite Edition)
Weight: 53 lbs Standard, 56 lbs Elite Edition
Dimensions: 17.5"(W) x 12"(D) x 7.5"(H) without tubes (1st gen)
Power output: Up to 10 watts per channel @ 32Ω
Signal noise: >95 dB; THD <0.05% at 1kHz
Inputs outputs: 2x XLR input, 1x RCA input; Headphone outputs: dual 3-pin XLR (L/R), 1x 4-pin XLR, 1x 6.3mm TRS; 1x XLR preamp output
Tube complement: 4x 6C45 driver tubes, 4x 2A3 power tubes, 1x 5U4G rectifier
Power consumption: 150W
Frequency response: 10Hz–60kHz, -2dB (1st gen, per Hi-Fi+); 10Hz–70kHz, -2dB (per Audio Advisor spec sheet)
Headphone impedance range: 8–600 Ohms