Typically most folks tiptoe in by getting a tubed preamp first. They are very low maintenance and will refine the sound. Then later once they are comfortable with tubes jump into tubed power amps. They will produce a bigger change, but typically are more expensive and if buying older equipment may require biasing and retubing which can cost some money. I finally switched to tube amplifiers a few years ago (then making my systems all tube) and am very sorry I did not do it decades ago. I have probably 5,000 hours of tube amplification listening now and vertically no different than solid state other than I retubed one component.