I was eyeing the WA6SE, but WA22 can take both single ended and balanced phone. With HD800 on the way, will be a natural choice for me; really like Woo Audio's industrial design, and their cnc milling are top class too.
I'm not so sure if the multitude of upgrades are such a great idea though. I've heard a few cases of hifi mod gone wrong when someone replaced a few stocks parts with "better" components.
Will be more reassuring if they just optimize the sound quality the best they can for each model. They can also streamline their production & logistics if there are less options available.
It's at the top of the WA22 page. It says" Pre-production unit shown, 6SN7 driver tubes will be used in production unit"
WooAudio 22 - Fully Balanced headphone Amplifier
WA22 is a fully balanced, Class-A, all triode-drive headphone amplifier, featuring 12AU7 driver tubes, 6080 power tubes, and 5U4G rectifier. Pre-production unit shown, 6SN7 driver tubes will be used in production unit
Special pre-order pricing is subject to end without notice.