Solude
Headphoneus Supremus
When I went through the amp round up the WA22 was bested by the B22 that was bested by the Soloist and it's a mini Dynalo so... GS-X mk2 will be another step up. WA22 is pretty expensive for what it delivers. And I liked it, but for $1900 plus another $600 in tubes you can do better for much less.