This of course depends on your preferences and the environment and volume where you listen to music. Theoretically, the sensitivity of 86db is not high. It is 7-10db different from the 93 and 96db I used. It seems that it is not suitable to use 300B single-ended push. However, the diameter of the woofer alone of my main speaker is 1SC, the height of the entire speaker, and the bass can reach 20Hz. Even the store owner who sold me the 300B didn’t think the 300B could drive such a large speaker, but I never had to adjust the volume beyond the 12 o’clock position. For the same two pairs of speakers, if the same manufacturer's KT88 push-pull is used, the push-pull position will not exceed the 9 o'clock position. So even the 300B still has room to use speakers with lower sensitivity. Although each volume design is different, this is a reference. Therefore, single-ended power of 300B or higher may not be impossible. As for push-pull, it’s not a problem if you want to push the common KT88 or 6550. Only you know whether they are suitable or not. My personal preference is 300B. This 1SC is not big and not heavy. If it were me, I would take it to a physical store for actual listening. Although it is not the environment at home, it is already the easiest way to find a tube amplifier that suits me.