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Woo AudioWoo Audio

WA33 (2nd generation)

The 2nd generation adds a direct-drive current output (TR mode, 3.3 A) for True Ribbon headphones alongside the standard HP mode.

Type
Valve headphone amplifier
Output
10 W into 32 ohms
Weight
24.5 kg
List
from $9,999

Output into any load

The line is what the WA33 (2nd generation) delivers, estimated from its published ratings. Each square is a headphone in the catalog at the power it needs for a loud 110 dB peak.

Grado Signature HP100 SE: needs 0.20 mW at 38 ohmsFocal Stellia: needs 2.51 mW at 35 ohmsFocal Clear MG: needs 3.98 mW at 55 ohmsMeze Audio Elite: needs 7.94 mW at 32 ohmsFocal Utopia (2022): needs 3.98 mW at 80 ohmsAudeze MM-520: needs 6.31 mW at 18 ohmsFostex TH900mk2: needs 10.0 mW at 25 ohmsYamaha YH-5000SE: needs 15.8 mW at 34 ohmsRosson Audio Design RAD-0: needs 15.8 mW at 29 ohmsSony MDR-Z1R: needs 10.0 mW at 64 ohmsHIFIMAN HE1000se: needs 25.1 mW at 35 ohmsFinal D8000 Pro Edition: needs 15.8 mW at 60 ohmsZMF Caldera: needs 31.6 mW at 60 ohmsMeze Audio Empyrean II: needs 100 mW at 32 ohmsAudeze LCD-5s: needs 100 mW at 35 ohmsMeze Audio ARTA: needs 15.8 mW at 225 ohmsZMF Vérité Closed: needs 12.6 mW at 300 ohmsDan Clark Audio Expanse: needs 100 mW at 26 ohmsAudio-Technica ATH-ADX5000: needs 10.0 mW at 420 ohmsDan Clark Audio Stealth: needs 100 mW at 23 ohmsSennheiser HD 820: needs 16.6 mW at 300 ohmsSennheiser HD 800 S: needs 20.9 mW at 300 ohmsAbyss Diana TC Signature: needs 100 mW at 72 ohmsAbyss AB-1266 Phi TC: needs 158 mW at 50 ohmsHIFIMAN Susvara: needs 501 mW at 60 ohmsPublished: 10 W into 32 ohms
Output into each loadPublished ratingHeadphone it drives at 110 dB (25)Needs more (0)Load in ohms across, power up, both on log scales

Build a setup with it

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Where to buy

from $9,999

Price: from, Standard Edition (Elite Edition costs more, price not published on Woo's page).

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Title block

Maker
Woo Audio
Model
WA33 (2nd generation)
Type
Valve headphone amplifier
Made in
USA
Output impedance
Not published
Weight
24.5 kg
List price
from $9,999 USD
Output power
10 W into 32 ohms
Topology
Fully balanced, push-pull, Class A, transformer-coupled, point-to-point wiring; 4x 6C45 drivers, 4x 2A3 power tubes, 5U4G rectifier; self-biasing
Finish
Anodized aluminium chassis (black or silver), PTFE tube sockets

What it drives

How the matching works

Ribbon headphones

From its direct-drive ribbon output.

1

Plenty in reserve

10 dB or more above loud 110 dB peaks.

25

Other valve amplifiers

Sources