*Left with 1 pc only.
Sophia Electric S.E.T. Princess 300B mesh plate tube is the upper-class model of the current 300B line (globe shape is still in production). This new tube is using the same 300B plate(as the globe 300B) with a stronger plate structure learned from making the original princess tubes. It is a true 300B tube. It will work with all 300B amplifiers (Western Electric 300B direct replacement).

The glass enclosure was from the Princess 206 tube for its unmatched sonic beauty. The shape of the glass enclosure does make a major difference. Just thinking of the violin’s shape, if it gets changed to triangle, the sound character of the violin will change for sure.

Sophia Electric engineers have conducted many hours of audition and comparison. In the end, the current shape of the Princess tube glass enclosure is the most preferred choice sonically. It has more volume and more curved than the old ST. It is not the old ST that came back rather it is a carefully crafted, researched new 300B model. The result is a 300B mesh plate tube with super clarity, low distortion and out of this world midrange fullness and liquidity. High-frequency extension and sweetness is the first thing you would hear.

This is a true 300B tube that is 100% interchangeable with the popular Sophia Electric globe-shaped 300B mesh plate tubes and Western Electric 300B tubes, as well as current production Chinese/Russian 300B tubes (with WE 300B standard).