It's show and tell.After several listening sessions,the most recent with a particularly fine bottle of Petite Syrah, I can,without doubt say that the quad of tubes I purchased from a fellow audiophile was the best I have heard in the AH.They are NOS of Russian origin.Etched on the tube are the numbers/letters 6H30,after the O there is an inverted U.There are no other markings to assist in identification of the brand.They came to me by way of the audiophile friend who acquired them from a distributor for KR products.It's all hush hush,but that just gets the juices flowing right.
To place things in perspective,the improvements over the Siemen/Halske quad were subtle.It was not emotionally immediate like going from the stock EH's to the Siemens.
There is an extra level of detail which provides a richer more 3 dimensional musical experience.It's like another layer of music was exposed with a presence and aliveness that is seductive.To summarize there is a complete sense of poise to the music,not that there wasn't before,its just a wee bit finer.And that's all I know.
