When you just go out and buy an amp, what you have is a compromise constrained by your budget, compatibility, etc. Those little SET amps have no juice and unless you're running K-horns, will have no head room or depth. Pbfffttt...
It's a totally different experience when you build a kit amp, like one of the VTA amps. You get enormous satisfaction from the build and you learn a great deal about operating and maintaining an amp. You don't get an ounce of that buying a standard commercial product.
With a kit amp, you get to choose what components go into it. Maybe you want to spend a little more on your coupling caps, or any number of other little improvements. You're much, much more involved in your gear and your system when you build from a kit. And lest you think it's not as good as a pre-built commercial product, remember that it was designed by a professional audio engineer. The VTA amps are extremely well thought of and rarely come up on the used market for a reason.
First Tube amp suggestions
I am thinking of buying my first tube amplifier and really have no idea where to start. Years ago I listened to a Sophia Electric el34 amp (SET) driving a pair of Joseph Audio rm7si bookshelf speakers in a very well set up room and could not believe how sweet they sounded together for the price. (It really felt like James Taylor was in the room). I regret that I never pulled the trigger on that system and do not know what a good entry level system would be nowadays. I listen mainly to male and female folk rock and an occasional classical or jazz album (Cd's and streaming from Tidal) My current speakers are Triangle Borea BR03's -90 db but am open to swapping them out. and the listening room is 14' x 20'. There is a lot of internet chatter about low cost tube amps like the Reisong A12 and the mid priced Williston R8. Are these amps worth buying or where should I start? Thanks in advance!