I have a 300b push-pull amp and have tried both types.There is a very big difference in this type of tube and I'd assume this carries over to the other types of tubes .I feel and hear a more of the music whith the electro-harmonics,more depth more, I dont know .they just sound so good. I would like to mention another tube you may want to investigate they are called Full Music . I can't find there web address right now but if you do a search it should come up. Just my two cents like it or not
