I was always very skeptical about selected tubes. I mean, how much different could it be from the non selected tube from a reputable manufacturer (we are not talking about Chinese tubes here). I got 4 Telefunken 12ax7 Selected Tubes when I purchased my McIntosh 275. I plugged then in, and they sounded very nice. Then I looked up the price of the tubes and they were going for $225 each!!! “This is crazy” I thought. How can a tube cost so much compared to the non-selected version that you can buy for ~$40 on a good day. Given that these were NOS and everything, but come on. So I put them away. Later on I decided to sell them – $900 is a lot of money for 4 small tubes.
“Regardless of what the Telefunken 12AT7s went into, they sounded consistent. The first thing people notice is that treble instruments are placed far back in the soundstage. In several rooms and systems, the hi hat on Peter Gabriel’s “Red Rain” and cymbals from Megadeth’s “Disconnect” were placed behind the plane of the speakers.” Read
The tube is the king of the tubes if used with care. This is superbly detailed tube with huge sound stage. Could be an overkill for a bright system, because it will make the system sound clinically bright and lifeless, but if mixed with warm sounding tubes (anything with black plates), it can produce and incredible sound that other tubes will be envious off 🙂
“Watch for the rare Telefunken smoothplates with a cloth label on the glass marked “selected tube”. Often these have red painted tips. . . These were all screened for critical use in medical equipment, with the “selected tube” or L&N versions being the best. Both red and blue tips are incredibly quiet and very three dimensional in sound.” Read