These tubes replaced the stock Sovtek 6L6 of an Epiphone Blues Custom 30. I didnt notice a difference in sound to be honest but what i seek is durability. I only have them for about 2 weeks so I will edit this review to the future.
It is also important to mention that Thomann delivered them to me securely, carefully packaged and they traveled a bit, so dont be afraid the transportation if you want to buy your tubes online