Accuphase DP 55 V Brochure

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Accuphase DP 55 V Brochure

Extracted text from Accuphase DP 55 V Brochure (Ocr-read)

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First-rate CD player built for no-compromise sound. Independent processor section features revolutionary MDS (Multiple Delta Sigma) converter with 24-bit ultra high precision. Full array of coaxial and optical inputs and outputs. Digital control of CD transport mechanism allows instantaneous optimizing of servo operation. Noise-free analog output with totally balanced configuration. The DP-55V is a further refined version of the model DP-55 coveted by audio connoisseurs the world over. It incorporates the latest advances in digital technology, allowing it to deliver superb Compact Disc sound. Independent use of the digital processor is also possible, providing excellent cost-performance ratio. The processor features a revolutionar y MDS (Multiple Delta Sigma) converter with superb 24- bit precision. This ensures ultra low distortion and outstanding signal-to-noise ratio. A set of digital inputs (coaxial and optical) lets exter nal digital sources also gain access to this superb D/A converter, for playback with opti- mum sound qual- ity. The DP-55V even provides digi- tal outputs (coaxial and optical), allow- ing connection of digital recorders such as CD-R, DAT or MD units. This lets you make direct digital recordings of supreme quality, us- ing the signal from the internal CD transport or from an external source. The CD transport section uses fully digital circuitry for control of all actuators and mechanical functions. This enables instant optimization of servo parameters for each individual disc as it is being played, resulting in stable operation and a drastic reduction of readout errors. The laser pickup is an ultra- compact type with integrated RF amplifier, and all actuators are driven by balanced circuits where no current flows in the ground line. A tray lock feature firmly secures the tray during playback, and the entire CD mechanism is mounted on a metal chassis of high rigidity, designed to minimize any vibrations that may arise during playback. In this way, the DP-55V covers every electrical as well as mechanical aspect to assure highly precise readout of the digital signal. A digital level control and balanced output circuitry are fur ther advantages for optimum sound. Digital Processor Section Innovative MDS (Multiple Delta Sigma) converter reduces distortion to theoretical limits and assures outstanding S/N ratio The D/A converter which generates the output signal is a newly developed type that provides excellent performance in terms of performance and sound quality. The MDS (Multiple Delta Sigma) principle em- ploys several delta sigma type converters in a parallel configura- tion which results in adrastic precision enhancement. The delta sigma principle combines oversampling with noise- shaping (a kind of digital feedback) which projects the amplitude information of the digital signal onto a time axis for precise conversion. Figure 1 shows several delta sigma converters which are fed with the same signal and whose outputs are combined to arrive at the overall waveform. In the DP-55V, two delta sigma converters are operated in parallel, which results in a performance improvement by a factor of 1.4 (=-2). An important characteristic of the MDS principle is that the performance benefits are achieved regardless of signal frequency and signal level. Therefore noise at very low signal levels that was difficult to contain with conventional delta sigma converters is now drastically reduced. The audible result is music reproduction emerging from utter silence with an impressive sense of clarity and nuance. Separate processor section with coaxial and optical input for digital signals Digital inputs allow the user to enjoy the top- level performance of the processor section also with other components that can supply a digital signal, such as another CD transport or a DAT or MD player. For utmost flexibility, the input can handle both optical and coaxial connections. Inter nal processing of audio data is carried out entirely in 24-bit format. Two digital outputs allow direct digital recording The DP-55V provides a coaxial and an optical output connector which allows direct connec- tion to the Digital Pream- plifier DC-330, or to a digital recorder such as a DAT, MD, or CD-R unit. The outputs carry not only the signal from the internal CD transport, but also from components connected to the digital input, allowing direct digital recording with un- precedented flexibility. Jitter-free high-performance digital demodulator Demodulation of the digital signal is carried out by a CS8412 chip (made by Cr ystal Semiconductor). This device not only has extremely low inherent jitter, it also is capable of absorbing any jitter components contained the input signal. Since the chip can handle digital signals up to a width of 24 bits, the advantages of the MDS principle can be realized with any type of program source. Linear phase analog filters provide superior phase characteristics The frequency upper range of the D/A converter output signal by principle contains noise components. The analog filter serves to remove such aliasing noise. The filter in the DP-55V is a 3-pole linear phase type filter with outstanding phase characteristics. The cutoff frequency is designed to minimize phase shift within the passband. Strict selection of all filter components assures sonic purity and total musical accuracy. Digital level control prevents sound quality deterioration The 24-bit MDS D/A converter in the DP-55V has an 8-bit margin, which allows precise level attenuation down to -40 dB without any loss in signal quality. Fully balanced analog output circuitry The audio output section features completely balanced circuitr y which is isolated from the ground line. Any noise that may be induced in Optical input display example Optical input display example Fig. 1 MDS type D/A converter principle Linearity (digital input vs. analog output) Digital inputSignal Conversion error MDS output Note the ratio between signal and conversion error. In the MDS output, the error is very small in relation to the signal. Digital input Analog output LINEARITY Digital outputs Digital inputs [dB] [dB]

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CD transport control assembly Comprises the CD transport servo control/key input/ display/output level microcontroller, balanced actuator drive circuit and other components. Digital I/O, D/A converter assembly Comprises the coaxial/optical digital input/output connectors, PLL circuitry, digital filter, MDS type D/A converter and other components.Analog output assembly Comprises the 3-pole analog filter, balanced/ unbalanced audio output circuitry, power supply circuits, unbalanced output jacks, balanced output connectors and other components. the signal path will be canceled out, so that the playback sound remains utterly pure and undiluted. For utmost flexibility, balanced XLR connectors as well as unbalanced RCA-type connectors are provided. CD Transport Section Fully digital control of CD mechanism The control circuitry of the mechanism section is fully digital, allowing the use of adaptive filtersto optimize servo performance for each individual disc. This assures enhanced operation stability and a drastic reduction in error rate. Laser pickup with integrated RF amplifier for error-free operation Since the output level of a laser pickup is very low, it is highly vulnerable to externally induced noise. To prevent such problems, the pickup used in the DP-55V employs an RF amplifier which is so compact that it can be directly Remote commander RC-18 Allows operation of all functions except power on/off. Enjoy superb convenience by switching input sources or controlling features such as direct play, program play and repeat play. integrated in the pickup assembly. This assures that the high-level output signal remains free from noise interference, which in turn reduces the error rate. Analog output with balanced circuitry