The second X7 series player, launched in Japan alongwith smaller siblings of the previous CDP-557ESD : CDP-338ESD, CDP-228ESD and the non-ES CDP-970 - good period, very good period.
If the center of it was the same, the KSS-190A and BU-10 drive, the X7ESD was a fair departure from the internal structure and componentry of the previous CDP-557ESD : the power-supply section was revised, displaced to the left (transformers) and back (power-supply), with the control and d/a section being separated and superposed one onto the other into to a narrower space.
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, many power-supplies coming out of two transformers, very generous regulations and copper heatsinking, copper bus bars - ES in all its grandeur.
Compared to the previous CDP-557ESD, the chassis structure was even reinforced with "Frame and Beam" : securing each (copper-plated) plate is done with "two on two" or even "three on three" layers.
One could play ping-pong with the chassis, it would mechanically remain as stable as can be.
After Sony's own d/a chips, then the Philips TDA-1541A period and before coming back to its own production, Sony went for Burr Brown digital-to-analogue converters but dropped the PCM64P of the CDP-557ESD for the PCM58P-S : an equally 18bit converter with very low noise ; Sony teamed two for a dual d/a scheme.
Very high-end was Sony's CXD-1244 : an 8fs digital filter with 45bit resolution, linked to a supplementary CXD8003 8MHz clock placed on the d/a side to keep pulses clean and properly in sync between the shaped-up RF signal up to the PCM58.
The D in ESD naturally stands for Digital : there's a regular 75 Ohm digital coaxial terminal at the back of the X7ESD, disparaged from its past of potential graphics provider with the use of other than P and Q CD sub-codes.
Circuit-wise, the X7ESD kept previous 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) and also GIC low-pass filters (one for each channel), FET-charged analogue outputs, Fine Ceramics feet and the Acoustically Sealed loading tray - a rubber band sandwiched between the drawer's front and the sub front-plate.
Visually, the myriad of front buttons vansihed :) but the Custom File system was also kept, sans alpha-numerical display - numbers-only and IR remote necessary.
The pair of balanced outputs was a novelty, not even present on the DAS-R1 masterpiece. It was here done like it never would be done again on any of the later X7s : a separate PCB dedicated to the balanced output stage holds two transformers, real transformers !
The build quality was and still is truly stupendous and the finish and feel of use is beyond anything ever produced - a real work of art, milimeter by milimeter, surface by surface, volume by volume.
The next model was the mechanically and visually similar but PULSE-loaded CDP-X77ES which became the most successful of the entire 1987-1994 X7 series.
If the later "7" players refined their abilities toward a more neutral tonal balance, wider sound and better dynamic range, the constant eBay bidding on these is a proof that this was no cheap jap'crap - no wonder Sony sold so many worldwide !
Used as a CD drive, it still beats the pants off the cheaply made optical blocks and mechanisms nowadays available.
And given the way hifi is going it will continue to do so for quite a while.
All ICs used and internal views you know where.
Cover of the september 1988 japanese catalog, the previous image being its main inside beautiful beauty shot.
The X7ESD is part of the last components made under the generic Sony AU (Sony Audio) T-Tag, before the separation of production schemes & plants into Sony DP (Digital Products), BP (Broadcast products) etc.
Sony AU throughout the earlier 1980s gradually replaced the old ASCO : Sony Audio Specialty COmpany.
The enormous copper-plated chassis, all done in double and triple layers.
The control & filtering board (top) and D/A board (bottom), as they are inside the X7ESD.
Not shown here is the small board dedicated to the balanced output.
Comparison between the BU-10 of the X7ESD (left) and Gibraltar drive of the lesser players (right), the actual G material being the grey compound.
