In high-end circles, the sonic repute of integrated-circuit op-amps (from "operational amplifier") is, at best, checkered. Of course, the expertise with which they are used and the parts they're used with can make all the difference. For example, my DIY preamplifier design, "AMP-02," published in Hi-Fi News & Record Review in 1989–90, and my earlier (1983–84) AMP-01 (footnote 1), I used the better IC op-amps of the time throughout. Both units were thought to outperform cost-no-object commercial units of the time that employed discrete transistors and even tubes, and only indicate what's possible.

The $1200 D-105u, the top of Luxman's CD-player line, is novel in its twin-triode vacuum-tube amplification in the analog output stage. This configuration is said to provide high linearity with low distortion and that hard-to-quantify musicality found in tubed products. In addition, the D-105u incorporates an anti-vibration laser pick-up mechanism and a high-mass magnetic disc clamper, the latter feature said to mass-load the disc center to minimize spindle-motor microvibration, thus improving tracking accuracy for lowest error rate.