Tube amp forethought

I would also suggest Atma-sphere amps. 

If you are considering Atma Sphere, I would also ask that you consider Sound Lab speakers.
Ralph holds them in high regard-which is saying something. At least, to me.
Bob

You don’t say if you have a ssd system now. I got into tubes via an Audible Illusions pre-amp. There are used ones available at modest cost. Tube pre-amps make a huge difference in sound.

SSD ?

nos tubes sound better have a lower noise floor and last longer than modern tubes
i see people get pricey tube gear and leave the chinese/russian mediocre tubes than they preach to swap every year scared of them to fail (ps audio)...
some modern amps like the schiit freya comes from the factory with microphonic tubes and people think it's part of the magic .(it actually is because all tubes are at least a little microphonic but those stock tubes are really crap ,the darkvoice 336 has a hum in one channel and people live with it) 
once you get the amp let it settle for a couple of weeks  with the stock tubes .then try to make a judgment about the sound what is missing or too much .than swap'em all without looking back for nos (made in uk,usa,germany or holland) with the sonics that you would like to add.i like mullard tubes ,ge's are nice as well .enjoy!