I always wanted to experience the 300b sound. But for forty years was pursuing planar speakers... pretty much the opposite direction... I needed massive power.
After retiring I decided to upgrade my headphone system that began with years of pursuing the best possible sound... I tried many high end head amps I imported one from Germany... then I found Woo head amps. After being really happy with a couple... I realize I could upgrade to their 300B headphone amp. So I got the Woo Wa5 and then tried a couple different 300B tubes... settling on Takatsuki 300B... arguably the best made.
Changed my life. The incredible power (this head amp comes with speaker outputs it is so powerful)... took total control of all the different headphones I had and produced the warmest, most detailed, musical, and powerful sound I have every heard. I can listen to them for hours. Many years later, I still listen to this system every day (see my virtual systems).
It also triggered a complete upgrade / change in direction of my main system. I realized my main system was sterile and analytical sounding. I swapped out all but one piece of equipment. It is now an all Audio Research system and has many similar characteristics to my headphone system, musical and natural sounding.
I also have a PrimaLuna integrated (I’m listening to it now). It does not start in the right place it get you there.
If you really want to experience 300B... you might try what I did. Apply 300B tubes to a headphone system. They have plenty of power for that. Then save up for some Takatsuki tubes... $2K per pair. Jaw dropping sound.
Generally speaking for main systems, you need more powerful components. But to get natural and musical... somewhat like the 300B, I recommend looking to Audio Research, Conrad Johnson, and VAC. These companies focus on producing natural and musical sounding systems.