If anyone decides with Raven Audio I would highly recommend you spend the extra money and go with their Osprey for that will supply you with a few extra years of quality sound and with upgrading tubes along the way and speaker and subwoofer added give a very nice musical sound for most starters into tube amps..
With these amps the best tubes are the ones Dave Thomson will suggest for your listening pleasures....He sure supplied me with tubes over years to keep me wanting to hear more coming out of the Osprey amp...But all Amps have a limit to how much you can get from them before you are looking for another to hear more detail and headroom ...