Three pieces of my audio gear run 6SN7's; Atma-Sphere MP-1 Mk3, MA-1 Mk3's and a Modwright modded CD player, a total of 22 6SN7's. After initial break-in, all 22 stock Chinese tubes in all three pieces were replaced with NOS. Needless to say, large improvements across the board.
The Atma-Sphere gear is almost ten years old and I have yet to replace a tube, not even a power tube. With all those tubes, I also thought it sensible to own a Hickok 533A tube tester and I check things periodically.
I'm not familiar with the UV-1 but I'd definitely check with Ralph. I remember talking to him early on about which tube positions in his equipment would bring the biggest improvements when rolling. He made it a point to say some circuits and some brands of equipment are more demanding on tubes. For example, a couple positions in the MP-1 require a 6SN7 GTB because it can handle higher plate voltages. Using a 6SN7GT, VT-231 or 5692 which can't handle the higher voltage will most likely cause an early death.
I've never counted but I must have over a hundred NOS triodes around here with a few nice rectifiers thrown in. Concerning 6SN7's, it seems to me that most of the noisy(kind of a spitty sound) and microphonic tubes I've encountered have been very old 6SN7GT's and their equivalents.
The red base RCA 5692 is a perfect example; some have a brown base and are branded Sylvania but were made by RCA. When they're quiet and up to spec, that tube can last beyond 10,000 hours and it can sound wonderful in the right gear. I've never had great luck with the various VT-231's either. They're an old tube and supposed to be a more "rugged" version made for the military. Most of the ones I've heard were microphonic.
The exception, and I'm guessing I was just lucky, is the highly sought after black glass Tung-Sol 6SN7GT sometimes branded VT-231. I found two pairs of them several years ago and was able to hear them in my own equipment before plunking my money down. They still sound and test fine; actually, they sound exceptional.
My advice, call Ralph. I'd also pick up a couple inexpensive RCA GTB's and give them a try. Some prefer the Sylvania's but to my ears they can sound a bit aggressive
The Atma-Sphere gear is almost ten years old and I have yet to replace a tube, not even a power tube. With all those tubes, I also thought it sensible to own a Hickok 533A tube tester and I check things periodically.
I'm not familiar with the UV-1 but I'd definitely check with Ralph. I remember talking to him early on about which tube positions in his equipment would bring the biggest improvements when rolling. He made it a point to say some circuits and some brands of equipment are more demanding on tubes. For example, a couple positions in the MP-1 require a 6SN7 GTB because it can handle higher plate voltages. Using a 6SN7GT, VT-231 or 5692 which can't handle the higher voltage will most likely cause an early death.
I've never counted but I must have over a hundred NOS triodes around here with a few nice rectifiers thrown in. Concerning 6SN7's, it seems to me that most of the noisy(kind of a spitty sound) and microphonic tubes I've encountered have been very old 6SN7GT's and their equivalents.
The red base RCA 5692 is a perfect example; some have a brown base and are branded Sylvania but were made by RCA. When they're quiet and up to spec, that tube can last beyond 10,000 hours and it can sound wonderful in the right gear. I've never had great luck with the various VT-231's either. They're an old tube and supposed to be a more "rugged" version made for the military. Most of the ones I've heard were microphonic.
The exception, and I'm guessing I was just lucky, is the highly sought after black glass Tung-Sol 6SN7GT sometimes branded VT-231. I found two pairs of them several years ago and was able to hear them in my own equipment before plunking my money down. They still sound and test fine; actually, they sound exceptional.
My advice, call Ralph. I'd also pick up a couple inexpensive RCA GTB's and give them a try. Some prefer the Sylvania's but to my ears they can sound a bit aggressive