For headphones I like the bass control and silence of SS, it can power cans down to 8 ohms! But it would nice to sample the tubes too, but they would need to be upgraded from stock sovteks which usually sound pretty rough. Buy em both for 600! Send one back, or not? It's a really schiity deal.
Sol has a headphone amp that some local headfi guys are using. I gotta give it another listen. Last time was bad system synergy with Sonos>Altmann. All that jitter leaked right through.