I purchased these tubes new from Sofia Electric in April of 2018 and they have been installed in my Sophia Electric Model 91-01 300B mono amps since then. They very closely approximate the sound of the original Western Electric 300Bs. These tubes have about 135 to 150 hours on them. They sound REALLY good, however, because I like to experiment with my system I decided that I would try out the flagship 300B tubes that Sophia Electric markets - The Royal Princess 300Bs. I can't afford to have two sets of expensive 300B tubes, so I'm selling the Classics.
Introducing Sophia Electric Classic 300B & Aqua 274B
After a few years of experiments and audition comparisons, Sophia Electric is proud to introduce Classic 300B tubes to the audiophile community. The Classic 300B has a unique blue glass but has the identical glass shape and metal plate structure of the vintage WE 300B. Most important, it has the soul and mid-range magic of the vintage 300B. To address the high frequency and bass limits of the original WE 300B, Sophia Electric has created a new rectifier tube - the Aqua 274B. The Aqua 274B will deliver exceptional high frequency and bass extension in the circuit to compliment the Classic 300B sonic character. Together this duo will produce the magical midrange of the original WE 300B as well as the high end extension and powerful bass response of a live performance.
Here is a recent User's review (other than me):
Just wanted to give you my additional thoughts on the Classic 300B
tubes. In the past few weeks I have listened jazz, orchestral, chamber and vocal music and I have to say these tubes offer a level of listening pleasure I have not experienced before in my listening room. You are correct that these are perfect for a 300B push pull amp. No matter what cd I played I sat mesmerized. Recordings that I am very familiar with sounded new and alive. CDs do not sound like digital 1s and 0s but live music. I don’t hear electronic artifacts and not once have I experienced fatigue or a sense of separation from the performers. What is really astonishing to me is how passionate performances sound with these tubes in my amps. I not only hear the realistic sound of a voice or a quartet or an orchestra but I can see in my mind’s eye real human beings bringing a piece of music alive. There is a human element to performances that is deeply satisfying and so often missing in reproduced sound. If someone wants to hear living breathing human beings making music in their music room, I recommend they try these tubes. They really are something special.
Jim, Washington, D.C.