One person claimed that best 1578 that he had heard was made in 63.
There are many variations among the Nos tubes.
I have three pairs of Raytheon vt231 but they sound different from each other.
I also enjoy Russian 6n8s made in 53 with nice bass, air and sparkle.
Now I have around 100 tubes of 6sn7 variants.
I am listening to National Union black glass which will be the last one in the shootout.
I will summarize my findings this coming weekend.
There are many variations among the Nos tubes.
I have three pairs of Raytheon vt231 but they sound different from each other.
I also enjoy Russian 6n8s made in 53 with nice bass, air and sparkle.
Now I have around 100 tubes of 6sn7 variants.
I am listening to National Union black glass which will be the last one in the shootout.
I will summarize my findings this coming weekend.