Listen to the PX25 tube...there is no doubt that this tube has more grunt...it is faster handling transients than a 300b, and not as warm, nor is the bass response as rolled off. If you listen to tubes within a line, you will find that every line imparts some bias...Cary and Audio Note are darker overall than Audion. But there are characteristics of each tube that transcend the lines, and may be magnified in some product lines, and diminished n others, but those characteristics define the sound of the tube. You need to decide what is important to your ear. If you like hard rock music, perhaps the EL34 or PX 25 would be a better choice than a 300B? Vocals and string instrumentals, acoustic guitar, the female voice, perhaps the 300B is the tube for you. Big soundstage, technicolor...maybe KT88s. Just make sure you listen to the tubes in the equipment that you intend to purchase, including the speakers and the front end. And you owe it to yourself to listen to Single Ended amplification before you decide.
