Our hybrid vacuum tube design sounds so real because it lets the individual gain parts each work in optimum environments. Vacuum tubes are great at manipulating voltages - you can play with 200+ volt signals where transistors would go up in smoke and flames. So, we use vacuum tubes for all voltage manipulations. Vacuum tubes, however, cannot drive difficult loads. They have very limited output current and get in big trouble trying to drive feedback loops, stray internal capacitances, and connection cables. So, we don't let our tubes see any loads at all. They operate in an idealized mode amplifying voltages only, and do it perfectly. Power MOSFETs are super current amplifiers. They can control great gobs of current without stress, and when properly selected and used, they perform without needing external compensation, thermal tracking circuits, or VI limiting and protect circuits. So we use all power MOSFETs for current amplification duties. There simply is no roughness or compression in Fet Valve amplifiers.