Be careful with recommendations of one variant or another being the
"absolute best". For instance: "The best 12AX7 is a 5751,
the best 12AT7 is "variant XYZ", etc."
While it is true that a PARTICULAR BRAND/VINTAGE variant can be
better IN YOUR EQUIPMENT, there are a lot of poorly made and
mediocre sounding variants of many types of tubes. For example, many
tout the superiority of the 5751 in my EAR phone pre. While it is true that
the Sylvania and GE 5751's sound very good in it, IMO they don't compare
to the Telefunken 12AX7. And I have some 5751's by other manufacturers
that sound much worse than some very ordinary 12AX7's.
"absolute best". For instance: "The best 12AX7 is a 5751,
the best 12AT7 is "variant XYZ", etc."
While it is true that a PARTICULAR BRAND/VINTAGE variant can be
better IN YOUR EQUIPMENT, there are a lot of poorly made and
mediocre sounding variants of many types of tubes. For example, many
tout the superiority of the 5751 in my EAR phone pre. While it is true that
the Sylvania and GE 5751's sound very good in it, IMO they don't compare
to the Telefunken 12AX7. And I have some 5751's by other manufacturers
that sound much worse than some very ordinary 12AX7's.