Naim DAC Folheto

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SHARC DSP
 Operates on the digital data to filter the out-of-band artifacts. 
40bit, 16 times over-sampling topology.
BLACkFiN DSP
 Handles USB, controls the DAC and 
conditions the incoming USB data.
DATA RAM
 Buffers the incoming S/PDIF data stream ready for re-clocking by 
the appropriate crystal oscillator.
APPLE AUTHENTiCATiON CHiP
  
Enables the DAC to access digital data from 
iPod and iPhone models. The Naim DAC is 
the world’s first Apple-Authenticated high-
end digital to analogue converter.
ANALOGUE FiLTERS
  
Two cascaded third order Sallen-key active 
filters giving 36dB/Octave roll-off. Each stage 
incorporates Naim zero-feedback 
complimentary buffers.
i TO V CONVERTERS 
Convert the current output of the 
digital to analogue converters to 
a voltage waveform ready 
for analogue filtering.
DSP TO ANALOGUE ELECTRiCAL iSOLATiON
  
Ensures that the high frequency noise of digital 
electronics cannot leak into the analogue output stages.
Technology under the hood
Designing an external digital to analogue converter 
capable of offering the exceptional musical performance 
obligatory for a Naim product brings numerous 
technical challenges. In particular, the S/PDIF interface 
protocol for digital interconnection has significant 
jitter and noise problems. Original solutions to these 
problems had to be conceived and developed. 
 
The Naim DAC has more in common with Naim CD 
players than with conventional external digital to 
analogue converters. It overcomes the jitter issues of 
S/PDIF by reading the data into a “rotating” data RAM 
buffer independently of its timing signal and reading it 
out again clocked by one of ten extremely low noise, 
fixed frequency crystal sine-wave oscillators. In terms 
of system topology, the DAC’s rotating memory is 
analogous to a rotating CD feeding raw data to be re-
clocked. The rate at which the memory fills and empties 
is controlled by the DAC automatically selecting the 
oscillator that matches the average incoming clock 
frequency. The data entering the downstream digital 
filtering and DAC chips is then completely isolated from 
the incoming S/PDIF jitter.
Along with being a source of jitter, S/PDIF is a 
potential source of RF noise. The Naim DAC 
suppresses S/PDIF noise through electrical isolation 
of its DSP front end from the digital to analogue 
converter and analogue circuits. Each element is also 
run from separate power supplies 
 
The Naim DAC’s digital filtering is handled by a powerful 
SHARC DSP chip running unique Naim authored code 
to create an ultra high precision 40bit floating point filter. 
The filter over-samples by 16 times on 44.1kHz data and 
provides stop-band attenuation of 180dB on all data. 
Following the digital filter are the two mono Burr-Brown 
digital to analogue converter chips, as used in the 
CD555 CD player. Finally the Naim DAC features a very 
high performance, low noise, and low distortion fully 
discrete analogue output stage. 
 
Ground breaking technology and digital audio engineering 
however are purely academic. Listening to the Naim DAC 
is something else entirely. Startling in its clarity, arresting 
in its detail, beguiling in its warmth and inspiring in its 
rhythm, the Naim DAC seduces from the first note.
The nature of music delivery is changing fast. CD has 
been joined by downloads, portable music players 
are part of the landscape, computers are routinely 
connected to hi-fi systems, and USB memory sticks are 
used to store high resolution music files. So the Naim 
DAC, our first stand-alone digital to analogue converter, 
arrives at an exciting time in the narrative of high quality 
music in the home. And listening to the DAC builds the 
excitement yet more. 
 
The Naim DAC marks a technical milestone comparable 
to our first CD player, the CDS. The CDS demonstrated 
that CD replay and lifelike music reproduction were not 
mutually exclusive. Now, the Naim DAC demonstrates 
that the jitter and noise that bedevil traditional external 
digital to analogue converters can be overcome and a 
new route to the real enjoyment of music opened. 
The Naim DAC provides eight S/PDIF inputs, two 
USB inputs, and is capable of handling audio data 
sampled at up to 768kHz and with up to 24bit resolution. 
It not only brings all the digital inputs together into 
the analogue domain, but does so with a level of 
performance that can compete with the finest from any 
Naim CD player to provide unrivalled musical fulfillment 
 
Listening to the Naim DAC is a revelation. Music, 
whether its source be an iPod, a CD or a high resolution 
data file, is presented afresh, with more definition, more 
insight, more warmth, and simply more of those hard-
to-define clues of rhythm, melody and emotion that 
distinguish the real thing from pale imitation. The Naim 
DAC is an advance that brings real music in the home 
closer to reality than ever before.
Naim digital to analogue - for the converted
Upgrade Path
Upgrades are a fundamental element of the Naim philosophy. As well as providing a significant performance 
upgrade for the CDX2 and CD5 XS CD players, and HDX hard disk player, the Naim DAC can itself be upgraded 
by the addition of an XPS or 555 PS external power supply.
The essential ingredients
Each element of the Naim DAC has a vital role to play 
in its musical virtuosity, but it is not just the specifics 
of each that is important, it is their organisation also. 
The influence of signal path, the microphony of 
circuit boards, the impact of track layout, the noise 
contribution of components, the noise sensitivity of 
others - each one is vital, and each one influences 
every other. 
 
 
The DAC signal path is fundamentally simple. The 
SHARC DSP, operating as a filter, receives the data, then 
over-samples and low-pass filters the data and feeds 
this to its peripheral memory. Also operating as a buffer; 
the memory outputs data clocked by the oscillator. The 
DAC chips turn digital into analogue current, and the I to 
V converters turn current into voltage. The analogue low-
pass filter removes high frequency artifacts, and buffers 
the signal for a preamplifier.
LOW NOiSE POWER SUPPLY  
Multi-regulated and smoothed 
power supply with separate 
outputs for each element.
CHASSIS
 
The 3mm aluminium 
chassis and machined-
from-solid fascia 
provide the fundamental 
structural rigidity 
necessary for low 
microphony.
DAC CHIPS
  
Burr Brown PCM1704k. A true multi-bit digital to 
analogue converter chip as used in the CD555.
RE-CLOCkiNG GATE
  
Re-clocks the data immediately before it enters the DAC 
chips to remove any influence from the isolation circuits.
CRYSTAL SiNE-WAVE OSCiLLATORS
  
Crystal oscillators have lower signal correlated noise 
and phase noise than voltage controlled clocks. The 
DAC employs ten 
separately tuned 
oscillators.
TRANSFORMER  
Low stray-field, 
multiple secondary 
windings.
PRiNTED CiRCUiT BOARDS
  
Six layer glass fiber PCBs 
optimised for low microphony 
and high speed data transfer.