This post is to spread the possibility of upgrading the glorious CDP-101 replacing the old DAC CX20017 with a double converter produced by Philips and that works with the standard Sony signal bus (not I2S). The new DAC is the TDA1311A and has only 8 pins. A simple base has been created that adapts the feet of the new dac to the preexisting CX20017. The attached schematic translates the pins of the old dac with the correspondents of the new one. It is a continuous calibration dac (CC-DAC) and it has already voltage output instead of current like the old one. After replacement, it is therefore necessary to remove IC508 and IC509 and bridge the pins 6 and 1 of the empty holes of IC508 and a bridge between pins 2 and 7 of the empty holes of IC509. Keep in mind that the output has the absolute phase reversed, but this is not a problem (many readers do). If desired, simply invert the signal by resetting the two ic 508 and 509 and modifying the circuit to eliminate this inversion. The integrated IC512 must be removed and the resistance R541 must be modified with 15 Kohm to make it equal to that of the left channel. With this double DAC the 11,34 us group delay (audible by expert ear or in MONO play) disappears in the fixtures with a single converter and the sound is updated bringing it closer to the much appreciated one of the Philips DAC. No more audio with harshness ... the sound becomes warm and velvety, even if the upper part of the spectrum is always present naturally. If you want to try, you can also remove the anti-aliasing filters F501 and F502 (removing them) by connecting directly pin 18 dac (out L) to pin 6 of F501 (and the same for the right channel pin 17 dac to pin 6 of F502) to have the unfiltered NOS version of Sony CDP-101, but I do not recommend it, because the unfiltered signals can be dangerous for the amplifier connected to the output.