A pure class A design transformed into a MK II model Capable of optimizing sound density Pursuing a sound that appeals to the senses whilst creating a deep musical impression is the ultimate role of the audio amplifier. With pure class A design, the L-550AXII integrated amplifier is a refined version of the L-550AX which was itself fully restyled in 2011. ‘The MK II model boasts improved functionality with the latest technologies equivalent to the higher grade L-590AXII such as Version 4.