Hi chungjh
With so many vintage 6SN7 nos tubes out there, why mess around with adaptors. There are a lot of people that feel that the 6SN7 is one of the best sounding audio tubes ever made for a preamplifier. I’m sure if you spend the money and find a reputable dealer you can trust who tests his tubes and properly matches the tubes that the sound quality will amaze you when compared to the factory tubes. I would recommend the better name brands from the 1950’s or the 1960’s. When you start getting into the middle to later 1970’s the quality starts to drop off. I would focus on the better name brands like Telefunken, Amperex, Siemens, or Mullard. These can be expensive but they can absolutely transform a preamp’s sound quality to a whole new level. Try Brent Jessee’s website. Audiotubes.com. For an extra $10.00 a tube he will properly match them with a curve tracer which is a piece of equipment a lot of these other tube dealers don’t have. I would recommend tubes with the same name brand, made in the same year and with the same date codes. Once you hear a great pair of properly matched, nos vintage tubes, you’ll never go back to using the factory tubes! Good luck.
Scot
With so many vintage 6SN7 nos tubes out there, why mess around with adaptors. There are a lot of people that feel that the 6SN7 is one of the best sounding audio tubes ever made for a preamplifier. I’m sure if you spend the money and find a reputable dealer you can trust who tests his tubes and properly matches the tubes that the sound quality will amaze you when compared to the factory tubes. I would recommend the better name brands from the 1950’s or the 1960’s. When you start getting into the middle to later 1970’s the quality starts to drop off. I would focus on the better name brands like Telefunken, Amperex, Siemens, or Mullard. These can be expensive but they can absolutely transform a preamp’s sound quality to a whole new level. Try Brent Jessee’s website. Audiotubes.com. For an extra $10.00 a tube he will properly match them with a curve tracer which is a piece of equipment a lot of these other tube dealers don’t have. I would recommend tubes with the same name brand, made in the same year and with the same date codes. Once you hear a great pair of properly matched, nos vintage tubes, you’ll never go back to using the factory tubes! Good luck.
Scot