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 MMB tpe D/A converter achieves 20-bit linearity and minimaizes noise |
| Two sets of digital inputs/outputs |
| Jitter-free high-performance digital demodulator |
| Fully digital control of CD mechanism |
| Balanced drive circuitry for servo motors |
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Preamplifier With fully Digital Signal Processing
From the outside, the DC-300 looks like a conventional analog preamplifier,
but internally, there are significant differences. All adjustments such
as volume, balance, tone control,loudness compensation, etc, are made in
the digital domain, using a 48-bit signal path and highly advanced Accuphase
DSP technology. Immediately before output. The signal is converted into
analog form by an MMB type D/A converter. Operation convenience is the
same as for other high-quality Accuphase preamplifiers, with the digital
principle opening up another dimension of clarity. Digital Volume Control
With Special Noise Shaper Processing Provides Smooth Analog FeelFor the
highly important task of volume adjustment, Accuphase introduces a new
noise shaping principle for digital level control (patent pending). This
circuit enables precise control down to an amazing -95 dB without deterioration
of signal quality.
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Control knob action is perfectly smooth with a pleasant feel and
natural-sounding level attenuation, just as in a high-class analog preamplifier.
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Digital gain controller
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MMB Principle Achieves 20-Bit Linearity and Low Noise
The D/A converter uses the amazing MMB (Multiple Multi-Bit) principle which
delivers top-notch performance and outstanding sound. It consists of eight
hand-selected 20-bit D/A converters connected in parallel. An important
characteristic of the MMB principle is the fact that it improves performance
regardless of signal level and frequency.
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Ultra Jitter-Free PLL Circuit
The operation of the D/A converter must be synchronized with the digital
audio interface (DAI) signal. For this purpose. a phase-locked loop (PLL)
circuit generates a master clock which is used as system reference. If
jitter or pulse distortion are present, the master clock precision will
suffer, which has a detrimental effect on the entire system. The Ultra
Jitter-Free PLL circuit in the DC-300 consists of a preamble detector and
a voltage-controlled oscillator (VCO) using a quartz crystal element. The
master clock produced by this PLL circuit is totally free from the effects
of pulse distortion and jitter.
High-Precision Sampling Frequency Converter
A sampling frequency converter (SFC) serves to transform the sampling frequency
of a digital input signal to a different value. In the DC-300 , the sampling
frequency is first converted to a higher value (up-conversion) and then
to the 48 kHz or 44.l kHz level 1 signal. The highly precise quartz oscillator
used for conversion assures flawless and virtually jitter-free performance.
20-Bit, 8-Times Oversampling Digital Filter
The NPC digital fitter in the DC-300 offers state-of-the-art characteristics
in all vital aspects, such as absence of group delay, passband ripple,
and attenuation, approaching the theoretical performance limits.
4-Pole Analog Filter With Hand-Selected Components
To reduce noise in the upper frequency range and achieve high S/N ratio,
a 4-pole Butterworth design is used for analog filtering. The cutoff frequency
point is optimized to keep phase shifts in the passband range at an absolute
minimum. Strict selection of all filter components assures sonic purity
and total musical accuracy.
Digital signal processing assures outstanding S/N ratio, perfect channel
separation, and minimum crosstalk
DSP provides high-precision tone control and loudness compensation functions without sound quality degradation
Versatile digital Input configuration with two sets of optical and coaxial connectors and optional provision for BNC, HPC optical and HPC balanced inputs
Analog Line Input Board Supplied as Standard Equipment, With Analog Disc
Input Optional
By installing the optional Analog Disc Input Board, the DC-300 can be used
to play your valuable analog record collection. The input can accommodate
MM or MC cartridges and comprises a switchable subsonic filter.
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Back view of DC-300 with option bords
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Two Sets of Optical and Coaxial Connectors Allow Recording and Playback
With Digital Recorders, and optional Connection for Analog Recorders
Recording output can be selected totally independently from the current
program source, allowing easy dubbing between two digital recorders or
between analog and digital equipment. A dedicated high-precision SFC performs
sampling frequency conversion for recording, which makes it possible to
flawlessly record any program source.
Versatile army of options for digital and analog inputs and outputs. Up
to sit optional boards can be installed in convenient rear-panel slob On
DC-300
User-selectable names for input positions
Fully Balanced Analog Output Circuitry
The analog output section features completely balanced circuitry which
is isolated from the ground line. Any noise that may be induced in the
signal path will be canceled out, so that the playback sound remains utterly
pure and undiluted.
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inside view of DC-300
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| * Guaranteed specifications are measured according to EIAJ standard CP-2402 |
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| * Specifications and design subject to change without notice for improvements. |
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Digital Stereo Preamplifier DC-300 
