Among the tube-rolling cognoscenti what are the details and specifications to look for when comparing and purchasing a pair set or a quad set of NOS Telefunken ECC801S tubes?
Which of these are the very best?
How much does the year of manufacture matter? Are tube vintages like wine vintages? Do tubes made in a particular year in the 1960s sound better than tubes made in a different year in the 1960s? Which is the best year?
Does it matter if the tubes were made in the same German factory?
Does it matter in which factory the tubes were manufactured? Which is the best factory?
Does it matters if tubes in a pair set or a quad set have matching serial numbers?
What does the "triple mica" specification mean?
What does the "diamond" -- <> -- designation mean?
Are some Telefunken ECC801s both "diamond" and "triple mica"? Are those the best tubes?
How closely should plate resistance and other electrical charateristics be matched?
Which is the best-sounding NOS vintage Mullard equivalent of the ECC801S?
Which of these are the very best?
How much does the year of manufacture matter? Are tube vintages like wine vintages? Do tubes made in a particular year in the 1960s sound better than tubes made in a different year in the 1960s? Which is the best year?
Does it matter if the tubes were made in the same German factory?
Does it matter in which factory the tubes were manufactured? Which is the best factory?
Does it matters if tubes in a pair set or a quad set have matching serial numbers?
What does the "triple mica" specification mean?
What does the "diamond" -- <> -- designation mean?
Are some Telefunken ECC801s both "diamond" and "triple mica"? Are those the best tubes?
How closely should plate resistance and other electrical charateristics be matched?
Which is the best-sounding NOS vintage Mullard equivalent of the ECC801S?