Like my Sony's - CDP-707esd, and CDP-X777es (they did after all - invent the CD media)
The following info came straight from "The Vintage Knob"
Sony CDP-707esd:
The original "7" series player, sold worldwide as a CDP-557ESD, in the US as a CDP-707ESD, and development basis for the reference CDP-R1 and DAS-R1 combo which was launched a few months after the 557ESD.
Unlike the R1 combo, the CDP-557ESD was still black and adorned with many a button and many a visible feature reminding us that this still was the 1980s.
But the work on textures, different anodizing, and structured volumes is typical of Sony's best design abilities. And this is all metal, too.
Inside, center stage, is the first version of the BU-1 aluminium diecast base which was reused in the next four models of the X7 series. The BU-1 holds the main motor, the laser's linear motor and its two magnetic rails and the precious KSS-190A.
The BU-1 assembly is known to be of the "almost everlasting" kind : read "more than ten years" of moderate but daily use. In reality, the actual lifetime of the laser, servos and motor can easily exceed twenty years.
Taking some from the CDP-555ESD, the chassis set the main layout for all following X7s : double steel plates, extruded 4mm front plate and drawer's front, copper-plating everywhere (including all the screws), ceramic-powder feet and ceramic-damped d/a chips.
The two transformers and the BU-1 drive are placed in their respective sub-enclosures, with felt pads added on and in between the double steel plates' sides and tops.
The BU-1E assembly itself rests on a Gibraltar sub-base bonded to the (top) bottom steel plate ; the BU-1E's own base also rests on a G sub(-sub)-base.
Gibraltar is made of calcium carbonate, glass-fiber and resin.
As all X7 players, the CDP-557ESD feels like a brick of solid steel but looks and sounds much better.
Digital-to-analogue-wise, Sony didn't yet use its own chips for the d/a section itself : after having done so between 1982 and 1984, Sony started using Philips' TDA1541A then Burr-Brown's.
The d/a chips in the 557ESD are two Burr-Brown's PCM64P (18bit resolution) teamed to a Sony CXD1144A 18bit / 8fs digital filter, the latter being the industry's very first 8fs digital filter.
As all of Sony's digital components between 1984 and 1994, componentry is lavish and oversized everywhere (caps are all premium Elna Duorex and Elna For Audio), 14 power-supplies coming out of the two transformers, generous regulations and heatsinking (in copper, too), solid copper bus bars - ES in all its grandeur.
Circuit-wise, the CDP-557ESD had sci-fi elements like Error Prediction Logic II (to "predict" read errors and correct them before they actually happen with an 1/10000th of second speed), a Servo Stabilizer II (to keep servo digital noise as low as possible), GIC low-pass filter (one for each channel) and FET-charged analogue outputs.
Nice touches-wise, there is an "Acoustically Sealed" loading tray (a rubber band sandwiched between the drawer's front and the sub front-plate), a myriad of programming modes assembled under the "Custom File" system and an alpha-numerical display which allows ten letters tops - Dmitri Chostakovitch will have to be abbreviated to Chosta
The D in ESD naturally stands for Digital : there's a regular 75 Ohm digital coaxial terminal at the back of the 557ESD, disparaged from its past of potential graphics provider with the use of other than P and Q CD sub-codes.
Unlike all later X7s, there are no balanced outputs (that was for the next generation - CDP-X7ESD) but, build-quality-wise, the 1987 top ES CD players were still made as japanese high-end was made before the 1987 and 1989 stock-market mini-crashes and the 1991 big crash.
The 557ESD and R1 combo are japanese high-end at its best and most lavish.
A CDP-557ESD built today, in 2010, would cost five or six times what it cost back then : nobody can afford to build like that anymore.
Sony CDP-X777ES:
One of the very few digital units I remember listening that shook my firm "analogue" slant, along with the Stax DAC TALENT and Sony's own CDP-R1a & DAS-R1a combo.
I couldn't afford an X777ES then, let alone the Stax, but I own one now - in fact I own two and I really didn't hear the need for a future upgrade for a long time.
As all Sony X7 players, the build quality is truly unbelievable and completely unseen nowadays.
The feel of use matches that quality : one has to see and touch these players to really understand what luxury in build-quality is.
It is no wonder Accuphase used Sony's drives for its own. And no wonder these sold like hotcakes in Germany and Japan : as all X7 players, the X777ES still is part of the crème de la crème when considered as a drive.
As an integrated player... better has been done since, for sure. And better had been done before, too : Sony's own CDP-R1 and DAS-R1 combo, albeit "older" in technology, has all the qualities of an X777ES... times 10 !
The price wasn't the same, though, in a ratio of one to four, and the PULSE circuitry, developed by NTT and Sony, became really better after the X777ES.
The R1 combo did have those magic Philips TDA1541A S1 converters, too.
Analog outputs are available in three flavors : RCA variable, RCA fixed or XLR fixed.
The fixed XLR are directly hooked to the PULSE D/A chips : very tight, very "direct".
The fixed RCA are the center of the show as they benefit from Toshiba FET transistors : sweeter, lush-ness comes in.
The variable RCA have too much cabling (from the d/a board to the motorized volume pot and back) and loose a lot of finesse along the way.
Depending on your preferences and the rest of your units, you will either prefer the fixed RCA or fancy the XLR - both are equally excellent, if in a different way.
Mods abound although not as numerous as the Philips-based Marantz (or Philips LHH) but one can already easily upgrade the original 16.9344MHz clock.
Sadly, in true Sony cost-multiplication style, the KSS-281A inside the X777ES was used only in the X777ES : original spares are now a faint souvenir and the only way to revive a tired X777ES is to find another... preferably lightly used.
If finding X777ESs is easy as that X7 model sold very well all over the globe, finding one which saw little use is more difficult.