billymav might know an alternative, maybe an Aune T1 Billy?
I amp mine with a Schiit Valhalla, probably the best low cost desktop valve amp there is. I personally didn't like my solid state Burson Soloist on it.. too glassy in tone, a bit hard/forceful for me. That amp is just great with my AKG K702's however. I think valves are the way to go.. I'm hopefully adding a Woo WA6 for both my 'phones:)