Sony CDP-502ES

Fourth generation CD player : still only the "subcode output" instead of the coaxial 75 Ohm digital PCM output of the bigger but contemporary CDP-552ESD. Only one power transformer, too.

The CDP-502ES was that everywhere but for the USA where it was named CDP-620ES.

The rest, inside, is pretty close if slightly less expensively built : partly copper-plated chassis, copper bus bars, abundant heatsinking, LC-OFC wiring, GIC low-pass filter, Nichicon MUSE, ELNA For Audio caps and very solid and long lasting overall assembly. Typical Sony :)

The d/a section inside the CDP-502ES is all-Sony, ending with two 16-bit CX-20152.

The BU mechanism/drive doesn't look exactly like those in the later X7 players but the system is the same : magnetic linear rails, super-fast movements and, again, very long life.

There are 5 or 6 versions of the BU drive, the first of which came with this generation of Sony CD players : CDP-552ESD and CDP-502ES. Sony named its CD drives as did Philips (CDM-x) but these naturally had nothing to do with Philips :)
The version used for that generation of Sony CD players was named CDM-4 ; the last one was the CDM-26, as used in the CDP-R10 masterpiece - and only in that one.

It should be noted that the "CDM" name, as used by Sony and unlike Philips, comprises everything from the loading assembly (tray, motor etc), the BU aluminium base (several versions there too) up to the spindle motor, laser diode and related PCBs.
Sony's CDM represent more of an internal assembly code name than the CD drive itself. And, again, there is nothing by, of or from Philips there.

It should also be noted that when the japanese catalog from which these images are taken from was published (june 1985), the original 1983 ES CD players still were available for sale and advertised as such : CDP-701ES and CDP-501ES - longevity, again.