I bought these tubes based on reviews and ...., at first after the first connection I was disappointed, the sound was quite rich, but only in the upper range, there was no bass at all, overall no dynamics, such a listening experience from transistors, but .... today they have been played for about 46 hours and the sound? It's great, the tubes have settled in, they have gained really beautiful dynamics, the bass line is not oversized, it is exactly as it should be, the mids are wonderfully rich, the highs are brilliant, I listened to the album Corvengence by Maila on the Cayin CS 88A amplifier and I really enjoyed it. All sound bands are fully occupied, every detail is wonderfully audible, so from the initial disappointment there is really a lot of enthusiasm. The tubes are really the tip of the iceberg from PSVANE, I haven't heard anything better yet and I have about 10 different sets at home. So whoever buys them should put up with the initial not-so-pleasing sound, it will get better over time after the burn-in, it really takes time. I believe that after 100 hours of playing it will sound excellent. Don't worry about it, I can really recommend it :)