Like the Xs 300, this amplifier was developed through constant and thorough innovation. After years of SIT device experimentation, followed by deployment in Nelson’s First Watt designs, circuit modification captured the unique tube-like sonic footprint of SITs from much higher-output MOSFET devices used in the Xs series. The result is unparalleled, fatigue-free listening enjoyment.
The SuperSymmetry design, which Pass has refined over the last 18(!) years, has been used as a starting point for the development of a new generation of power amplifiers. The total development process took three years, with listening as the main starting point. And then no quick AB or ABX tests, but listening to music over longer periods on your own sets at home. The final result is the Concept series, consisting of 2 models of mono power amplifiers with external power, the Xs 300 (300 W.) and the Xs 150 (150 W.).
This concept, of course designed by the legendary Nelson Pass (output stage, power supply) together with Wayne Coburn (input stage, and together with Nelson power supply) will form the basis for all Pass power amplifiers for years to come.