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 (or BU-10 later on) assembly is known to be of the "almost everlasting" kind : read "about ten years or more" of moderate but daily use. In reality, the actual lifetime of the laser, servos and motor can 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' TDA-1541A and Burr-Brown's PCM chips.
There probably was an industrial deal behind this but I have no details about it - yet.
The d/a chips in the 557ESD are two Burr-Brown's PCM64P (18bit resolution) teamed to a Sony CXD-1144 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.
The chips you know where to find and many "nudie" images and detailed descriptions (and enthusiasm) by Lukasz Fikus.
Structure of the 557ESD :
it doesn't look like that because it is quite filled up, but the entire chassis is copper-plated, all heatsinks and screws included.
If you zoom-in on the tray area, you'll see the 4mm thickness of the extruded aluminium front.
The big caps at the analogue audio regulation were upgraded after this sample / cutout model : from For Audio (black) to Duorex (red).
The production audio board.
The BU-1E of the CDP-557ESD - which looks like any other BU-1x from any of the X7s.
There are 5 or 6 versions of the BU drive but, strictly speaking, the BU isn't the complete drive.
Sony named its CD drives as did Philips (CDM-x) even if these naturally had nothing to do with Philips :)
The version used for the 1984/85 generation of Sony CD players for instance was named CDM-4 ; the last one was the CDM-26, as used in the CDP-R10 masterpiece.
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.
Practical example : the Sony drive in the CDP-R1 consists of three ensembles :
- CDM4D-10
the entire loading assy, puck, base plate, PCBs etc which holds...
- BU-1x
the aluminium base, spring+rubber suspension, motor, spindle, sensors etc which holds...
- KSS-xxx
the oh so precious laser block.
Note to X7 owners
Lasers do age and eventually die (there is no way around that) and I can NOT help you in in finding a spare laser block.
I have none in stock and also pray my X777ES and R1 will hit world record by lasting another 20 years.
The american version : CDP-707ESD.
After the CDP-101 and CDP-701ES in '82/83, Sony US decided to name its CD players differently than in Europe or Japan.
This was followed as well for DAT recorders later on... but not the amplifiers or tape decks - why make simple ?
Sony AU also decided on doing that as well... in part. Because complicated is so much more fun !
Image from the march 1988 USA ES catalog.
A very old scan, circa summer 2004, which I alas can't redo now :(
