Here is what John Tucker says you can use:
6829 (standard), 5965(recommended by John), 7062, E180CC, or CV8431 optional direct plug ins.
You don't need to go crazy and spend uber dollars. John designed it that way.
For convenience, here is a some general info on each tube:
5965:
This industrial tube is close enough to the 12AT7 that audiophiles have started buying them up and commenting on the low noise of this tube. It most likely is because it has a lower gain, a mu of 47 compared to 60 of a 12AT7. It is kind of like using a 5751 in place of a 12AX7--the lower gain being the main difference. These tubes are still plentiful, and are really well made. GE made a fine version of this tube in their "5-Star" broadcast line. A few have an extra mica spacer on top, known as "triple mica" and noted for lower microphonics. There is also a rare Telefunken version of this tube with long plates.
E180CC or 7062:
Most often found in European types, typically Amperex or Philips, this tube is virtually the same as a 5965 in regard to electrical specifications. Audiophiles have been seeking it out since the price is generally lower than the premium ECC81 NOS prices currently. Like the 5965, it has slightly lower gain than the 12AT7, and has the added advantage of a 10,000 hour heater life to make it another audiophile "secret" tube. A super bargain when you find them, since they are musical and smooth to listen to, and actually sound better than many standard 12AT7 tubes. Better grab them now while the prices are still low! This tube is about a half-inch taller than the standard 12AT7, so chassis space is an important consideration.
6829:
Yet another industrial tube that is very similar to the 5965. This one has a mu factor of 47 so it is slightly lower than the typical 12AT7. Those I have heard are rich, detailed, warm, and thanks to the lower mu, very quiet and low in microphonics. GE made these in their 5-star and military line so they are a rugged and long lasting tube. Like the E180CC, this tube is about a half-inch taller than the 12AT7, so you need to consider overhead chassis or cabinet space when swapping a 12AT7 with one of these. An excellent audio bargain now, but prices may soon climb as audiophiles discover them!
6829 (standard), 5965(recommended by John), 7062, E180CC, or CV8431 optional direct plug ins.
You don't need to go crazy and spend uber dollars. John designed it that way.
For convenience, here is a some general info on each tube:
5965:
This industrial tube is close enough to the 12AT7 that audiophiles have started buying them up and commenting on the low noise of this tube. It most likely is because it has a lower gain, a mu of 47 compared to 60 of a 12AT7. It is kind of like using a 5751 in place of a 12AX7--the lower gain being the main difference. These tubes are still plentiful, and are really well made. GE made a fine version of this tube in their "5-Star" broadcast line. A few have an extra mica spacer on top, known as "triple mica" and noted for lower microphonics. There is also a rare Telefunken version of this tube with long plates.
E180CC or 7062:
Most often found in European types, typically Amperex or Philips, this tube is virtually the same as a 5965 in regard to electrical specifications. Audiophiles have been seeking it out since the price is generally lower than the premium ECC81 NOS prices currently. Like the 5965, it has slightly lower gain than the 12AT7, and has the added advantage of a 10,000 hour heater life to make it another audiophile "secret" tube. A super bargain when you find them, since they are musical and smooth to listen to, and actually sound better than many standard 12AT7 tubes. Better grab them now while the prices are still low! This tube is about a half-inch taller than the standard 12AT7, so chassis space is an important consideration.
6829:
Yet another industrial tube that is very similar to the 5965. This one has a mu factor of 47 so it is slightly lower than the typical 12AT7. Those I have heard are rich, detailed, warm, and thanks to the lower mu, very quiet and low in microphonics. GE made these in their 5-star and military line so they are a rugged and long lasting tube. Like the E180CC, this tube is about a half-inch taller than the 12AT7, so you need to consider overhead chassis or cabinet space when swapping a 12AT7 with one of these. An excellent audio bargain now, but prices may soon climb as audiophiles discover them!