Sony CDP-X77ES CD player Measurements

Sidebar 3: Measurements

Most of the measurements, except as noted, were made through the fixed-level, unbalanced outputs. I checked the AC voltage from chassis ground to main (house) ground to determine the correct line-cord orientation using a cheater plug (footnote 1). The Sony measured around 53V with an inconsequential difference in the reverse plug orientation. This is higher than desirable, though the voltages will be shunted to ground when the player is connected to a properly grounded preamplifier.

I checked the Sony's tracking ability with the dropout tests on the Pierre Verany Digital Test CD. The Sony mistracked when the dropouts reached 1.25mm in length; the CD Standard only requires tracking of a 0.2mm gap, although theoretically the error-correction codes make regeneration of gaps of up to 2.47mm possible. The CDP-77ES was non-inverting from all of its outputs.

The Sony's frequency response redefined the concept of "ruler-flat" from 20Hz to 20kHz though its fixed and unbalanced outputs (fig.1). Through the balanced outputs, however, the response (fig.2) showed a sharp 1.4dB peak at about 12Hz, returning to zero by 20Hz, then echoing the response of the unbalanced outputs up to 20kHz. Through the variable outputs (not shown), with the front-panel volume control set to its halfway position, the HF response began to droop at 3kHz, reaching –0.6dB at 20kHz, this due to a high output impedance from these outputs: at full volume it was just under 200 ohms, but at the half setting of this control, the output impedance increased to a rather high 4475 ohms, suggesting that the volume potentiometer is not buffered. The output impedance of the balanced outputs was 666 ohms; through its fixed-level, unbalanced outputs, it was just under 200 ohms.


Fig.1 Sony CDP-77ES, unbalanced frequency response at –12dBFS (right channel dashed, 0.5dB/vertical div.).


Fig.2 Sony CDP-77ES, balanced frequency response at –12dBFS (right channel dashed, 0.5dB/vertical div.).

Separation (fig.3) remained greater than 110dB up to 5kHz on the worst channel, then decreased to 100dB at 16kHz. The de-emphasis error was practically non-existent.


Fig.3 Sony CDP-77ES, channel separation.

Spectral analysis of a 1kHz undithered tone at –90.31dB (fig.4) is strikingly good, without question the best we have measured on any all-in-one player, and equaled only by the Stax and Esoteric D-2 processors. The same goes for the Sony's low-level linearity (fig.5); the right channel only is shown, the left was slightly better at less than 2dB departure from the correct level down to below –112dB! And the Sony's 19+20kHz IM was similarly superb (fig.6), with nothing amiss worth commenting on.—Thomas J. Norton


Fig.4 Sony CDP-77ES, spectrum of dithered 1kHz tone at –90.31dBFS, with noise and spuriae (16-bit data, right channel dashed).


Fig.5 Sony CDP-77ES, right-channel departure from linearity (2dB/vertical div.).


Fig.6 Sony CDP-77ES, HF intermodulation spectrum, DC–22kHz, 19+20kHz at 0dBFS (linear frequency scale, 20dB/vertical div.).

Footnote 1: That is, both prongs are the same width, enabling it to be plugged into an outlet in any direction. Some audiophiles hold that equipment should be plugged in with an orientation which provides the least voltage on the chassis (before hookup to other equipment) for the best sound. I try to hook up my equipment this way—it costs nothing except investment in a decent voltmeter. Even "keyed" two-prong plugs, incidentally, are not always correctly wired at the factory for the correct orientation (minimum chassis voltage), requiring the use of a cheater plug.—Thomas J. Norton
Sony Electronics Inc.
16530 Via Esprillo
San Diego, CA 92127
(858) 942-2400

Allen Fant's picture

Thanks! for the memories. My 1st cd player back in the 80's was a Sony ES (for better or worse). In 2016, I am still an "ES" fan.
It is like never forgetting your 1st taste, I mean, 1st cd player.

volvic's picture

I still have 2 cdp-111'S and have owned several 101's and quite few ES players over the years. Some were more reliable than others but the construction was solid and I thoroughly enjoyed the machines. To me it represents Sony's glory years. Good times, thank you as well for the memories.

latinaudio's picture

I still own a Sony XA7ES, also reviewed in the magazine.
A later model than this one, with the fixed laser beam mechanism, is still in use with flying colors: smooth, clear, pleasant sound.
The shortcomings of a unit in a review not always correlates with the pleasure of its use on the long term. In this case, it seems to me that the reviewer hit the nail when he said that "both drew this listener into the music in a way that the other players did not".
18 years after my Sony still made that, although surpassed by new designs.
Call that value !