We have reviewed L-590A, the memorial model for 80th anniversary of our foundation, from its basic performance, refined it, and finally developed the second version, that is L-590AII. The separation performance has attained to the level of high-end models by carefully examining all the circuits including introduction of the pure class A operation with 30W + 30W (8Ω) to acquire condensed sound reproducibility and the high sound quality selector switch IC used in the top-end control amplifier, C-1000f. L-590AII is a top-end model of our integrated amplifier with pure class A amplification method, which is refined to the details by increasingly pursuing strong drive force and condensed sound.