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轉 MODELO D/A-CONVERTER 技術特性如下
MODELO D/A-CONVERTER
This D/A Converter features extremley compact digital technology. The compact layout of the
components means that sophisticated technology, which is usually found only in large units, can be
fitted into small MODELO-sized units. A construction technique that eleminates wiring ensures high
operational realiability and short signal paths.
‧Jitter Rejection
Input stage with especially high jitter rejection (supression of clock fluctuations in the digital music signal) to give much more detailed sound reproduction.
‧ Precision Digital to Analog Conversion
4 High-End hybrid D/A (Bitstream for lower Bits, Multibit for higer Bits) conversion with 8 times
oversampling - this conversion system exhibits no inherent zero distortion, or problems with bit
alignment, converter monotony or ageing. The Signal is digitally balanced.
‧ Top Class Analog Signal Processing
Sophisticated analog signal processing using high-precision FET amplifiers and very tightly
toleranced electronic components characterised by extremly low loss factors and particularly good
transient response and harmonic distortion allows a reproduction with great richness of detail,
precise spatial separation of music and without harshness.
‧ Power Supply
A stabilised power pack
with separate torodial-transformers
for each channel, a secondary power filtering circuit, in excess of 50,000 μF of capacitors and 6 regulated supply voltages ensure
dynamic response, bass control and precise spatial representation.
‧ Printed conductors are twice as thick as usual (70 μm) to minimise acoustic losses on the printed circuit board.
‧ Rounded-edge printed conductors in the digital circuitry prevent field-strength concentrations that distort sound.
‧ Very short signal paths thanks to modern, computer-optimised circuit layout.
Technical Data:
24-Bit decoder
DAC resolution over 20 bit multibit standard
Balanced ringing free digital filter
Frecuency response: 1 Hz - 20 kHz, digital deemphasis
THD: 0.005%
Signal to Noise ratio: >110 dB
Channel separation: > 95 dB
Output Level: 1.8 V max.
Class A output stage
POWER
D/A-CONVERTER
INPUT STATUS
CD AUX DAT DATA EMPHASIS OPTIC. COAX. ERROR
Ultra fast Logic
A typical digital signal is a squarewave with 0 V for logical ow?and 5 V for logical igh?
An ideal squarewave does not exist because of the finite rising and falling speed of logical devices.
A usual high speed logic device needs a time of app. 10 ns to rise from ow?to igh? The devices
used in the Candeias DAC have only a risetime of app. 1.5 ns.
Logical devices have no exactly defined switching point from ow?to igh? The value for this point
lies between app. 2.5 V and 3.5 V.
The consequence is an additional random jitter of max. 2 ns for a usual high speed device and only
0.3 ns for the ultra high speed devices.
For better understanding an example:
A complete optical data tramission with ST fibers causes a random jitter of max 2 ns. The same
transmission with a well made oslink?fiber causes 20 ns of random jitter. We all know that this
difference is audible!
9 (usual high speed) logical stages in the digital signal path of a DAC cause the same difference of
random jitter. But because of the higher frequencies in the DAC clocks the same audible difference
happens with app. only 3 usual logical stages. Using ultra high speed devices the random jitter
decreases to a seventh part.
Ringing Free Digital Filter
Differences between usual digital filters and the filter constellation used in the Candeias DAC:
Long FIR-digital filters (Fig. 1) have a pre and a post ringing. The ringing energy originates from the
pulse peak.
The filter used in the Candeias DAC (Fig. 2) has a full pulse peak and no ringing. The pulse is not
meared?in the time axis. The result is a more detailed sound with no igital?harshness and a very
natural spatial reproduction.
Ringing Free Digital Filter
Differences between usual digital filters and the filter constellation used in the Candeias DAC:
Long FIR-digital filters (Fig. 1) have a pre and a post ringing. The ringing energy originates from the
pulse peak.
Balanced Hybrid DAC:
Bitstream (one bit) converters have an unbeatable low level performance, no glitch energy and a
good low level linearity.
Multibit converters have a good dynamic performance and no need for higher order noise shaping.
The hybrid converters used in the Candeias DAC have a bitstream converter for lower levels combined
with a multibit converter for higher levels. The result is a DAC with very low glitch energy, only a first
order noise shaper for the bitstream unit and a very good dynamic response.
