I already have a solid state amp. I am looking for a different sound and I think I should now venture into the land of tubes. This will primarily serves as a preamp for speakers, and as a headphone amp secondarily. So "quality" have more priority than "power" here.
It also should not sound like a solid state amp, meaning it should not sound dry and should have at least some liquidity in midrange typical of tube. I also won't be building a bunch of them so please don't tell me to build them all and see which I like best. Most likely (I hope) this will be my last. The design should also have good community support, I am confident about putting parts together but when things go wrong I often have little clue.
It seems that my best bets are among Alex Cavalli's design, but I can't decide which. I thought I decided in the SOHA II but the more I read the less sure I am.
Take a look at Eric Barbour's "Brute Force" over at HeadWize. It's tubed all the way through and you can even use tube regulators. Those light up blue/purple and are very cool. The amp is designed as both a preamp and headphone amp.
Though it is an OTL with a relatively high output impedance. Would that work with your headphones?