Sony SCD-C555ES SACD changer Page 2
Inside the SCD-C555ES
Sony's multichannel SCD-C555ES is a five-disc carousel changer for SACDs and CDs with a Direct Stream Digital (DSD) decoder and built-in Multichannel Bass Management (MCBM). It features a twin fixed-pickup laser-tracking assembly, an optical pickup with dual lasers (650nm SACD, 780nm CD), and a Direct Digital Sync D/A clock system. It plays CD-Rs and CD-RWs, can read and display CD/SACD text, and has a headphone jack with a level control. Also included: direct disc selection plus track access via a jog dial; 32-step programming for all discs; all-discs/all-tracks repeat functionality via remote control; and a two-mode fluorescent display.
The MCBM bass-management system was designed to overcome loudspeaker issues of placement and/or configuration. "Based on the speaker configuration and the frequency response of each of the speakers in the system (Small or Large)," Sony claims, "low-frequency signals can be redirected to a subwoofer in the system." In addition, "one can adjust the Channel Level to optimize the distance from the listening position. One can also set the balance between the front/surround and front/center....All of these functions are accessible via the player's menu system and remain in the player's memory until changed by the user. Level balance can be adjusted via the unit's remote control." Finally, "if the ideal speaker configuration is available—five full-range channels placed at equal distance from the listening position—Multichannel Management's 'Direct Mode' feature bypasses all processing and sends full-range signals to all speakers in the system."
To manage the multichannel SACD signals, the SCD-C555ES uses a new DSD processor quite different from what's found in Sony's SCD-1 and SCD-C333ES players. Says Sony on its website, "This processor demodulates the RF, corrects data errors, and extracts the clock and synchronization signals. It provides six discrete full-bandwidth channels. For multichannel sound, a D/A converter circuit block is required to play back all six channels equally. It contains a DSD filter which removes unwanted super-high-frequency noise....The calculated result achieved with the DSD filter is directly input into a unified multi-level DAC. This is the composition of multiple sources from the same current, and enables conversion to a highly precise analog signal. The SA DAC also has 24-bit processing and [an] 8x-oversampling digital filter for CD playback." However, the SCD-C555ES does not feature the four selectable, 24-bit Variable Coefficient Filters for CD playback found in other Sony SACD players.
To improve mechanical rigidity, the C555 has two-layer frame and plate construction to isolate the disc transport mechanism from the power supply and electronic circuitry. The Sony website continues: "Since a five-disc changer requires a large space within the player to be allocated to the carousel tray, the chassis has to be carefully considered in order to maximize the performance. The new frame and plate construction consists of two structures within the player. The lower plate contains the carousel and the power section. In this way, the weight of the power supply is distributed to the lower section in order to provide a well-balanced center of gravity. The second plate separates the upper level of the interior of the unit and provides a firm foundation for placement of all of the unit's circuit boards. This also has the effect of shielding the circuitry from motor noise (from the carousel mechanism) or magnetic flux leakage from the twin transformers."
Further enhancements include dual R-Core power transformers, one dedicated to the audio section, the other dedicated to the servo and digital system; gold-plated line outputs; an aluminum front panel; a motorized front-panel door; off-center insulator feet. The customer is protected by a five-year limited warranty. However, this may not be necessary—the fit'n'finish of the C555's cabinet is unusually substantial for a product costing less than $2000; it should operate reliably for years.
The SCD-C555ES has a complete set of controls on its front panel. As did Jonathan Scull in his April 2001 review of the SCD-C333, I loved the AMS knob at the right-hand edge of the front panel—it lets you instantly dial in the desired track of a SACD with a simple twist. The SACD/CD button toggles between the SACD and CD layers of hybrid discs, and the Mult/2CH button toggles between a disc's multi- and two-channel mixes. Unfortunately, these crucial togglings can't be made while the music is playing to permit instant comparison of the same music in the different formats. The handy remote is a slender bar that duplicates the front panel's controls.