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Preamplifier / DAC / Digital Crossover / EQ / USB Soundcard
DCN28 is a true high performance Digital Crossover Filter, Pre-Amplifier and Room Correction
in one unit.
DCN28 will serve as the heart of an advanced active sound system and replaces the
ordinary analogue preamplifier, USB DAC and/or external DAC.
True high performance Audio Products often takes a lot of engineering time and our new DCN28
is absolutely no exception. But rest assured that this is no ordinary audio
product that might enhance the performance of your sound system - it will definitely lift the overall
sound quality to another level.
DCN28 Silver Front Panel
DCN28 Black Front Panel
What will you have to do, you ask...
You will have to turn your system active, which will require a number of changes - like multiple power
amplifier channels, removal of the passive crossover filter in your loudspeaker and some new cabling.
There are some nice examples in our Customer Gallery
section of how this is done and it's done by our customers themselves...
OR you could make your own Do It Yourself loudspeakers which you also can see a lot of examples of in the Customer Gallery.
If this is a bit overwhelming for you at first sight, don't dispare - our dealers, our distributors and we at Ground
Sound can assist you in every aspect of the implementation. We can even make custom-made solutions, which
will fit perfectly into your Listen Room or Home Theatre.
YOU just have to be willing to let go of the traditional passive loudspeaker system !
 DCN28.pdf User Manual
DCN28 is supplied with the XOverWizard II advanced software which is a graphical
tool to manipulate with inputs, outputs, gain, crossover frequencies,
crossover slopes, equalization and delay. The software features measurement engine,
post processing tools, optimizer engine with target option, output listing and direct
transfer to the crossover setup environment. There are no limitations or constrains in
the XOverWizard software. More details at the
XOverWizard II page. |
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Details of the DCN28
- - - - - - - - - - - - - - - - - - - - - 30VA main toroidal transformer - - - - - - - - - - - - - - - - - - -
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The foundation of a true high performing Audio Component is a stable power supply.
DCN28 has a well dimensioned 30VA toroidal transformer with separate
secondaries for each of the required supply rails. The transformer is custom-made
and it's specified for audio application. Often digital crossovers are equipped with
Switch Mode Power Supplies, which degrade the audio performance significantly.
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- - - - - - - - - - - - - - - - - - - Low consumption StandBy mode supply - - - - - - - - - - - - - - - - -
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Besides the main toroidal transformer the PSU board has a smaller mains transformer to power the front control panel giving low power consumption in standby mode.
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- - - - - - - - - - - - - - - - - - - - - - - - - - Capacitor Bank - - - - - - - - - - - - - - - - - - - - - - -
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Another important part of the power supply for the high performance Audio
Component is the capacitor bank which stores energy and reduces the ripple on
the unregulated supply lines. DCN28 has more than 40.000µF, which is more
than many power amplifiers have !
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- - - - - - - - - - - - - - - - - - - - - - - - - - - Mains Filter - - - - - - - - - - - - - - - - - - - - - - - -
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The power supply in DCN28 features a mains filter to minimize potential noise and
glitches from the mains supply. This mains filter together with the well dimensioned
main transformer, the massive capacitor bank, lots of local decoupling and
individual voltage regulation for all Integrated Circuits give you a noise immune
system.
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- - - - - - - - - - - - - - - - - - - - - Analogue to Digital Converter - - - - - - - - - - - - - - - - - - - -
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DCN28 has two sets of balanced analogue inputs equipped with gold plated Neutrik
3-pol XLR connectors. The conversion from analogue to digital is performed by a
high grade Burr Brown AD converter at 96kHz and 24bits resolution. The maximum
input level is optimized for standard output swing of 2V RMS from normal sources
like CD players, tuners etc. to best exploit the full 24 bit range. The input
sensitivity is optimized for normal outputs of 2Vrms.
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- - - - - - - - - - - - - - - - - - - - - - - - Digital Audio Inputs - - - - - - - - - - - - - - - - - - - - - - -
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DCN28 features 4 digital audio inputs: Coaxial S/P DIF, balanced AES/EBU and
two Optical TOS-links. The Coaxial and the balanced AES/EBU are isolated from
the source by a digital audio signal transformer and loaded with the optimal
impedance. The optical TOS-link is in its nature also electrical isolated from the
source. This eliminates noise coming from the sources.
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- - - - - - - - - - - - - - - - - - - - - - - - USB Audio Streaming - - - - - - - - - - - - - - - - - - - - - -
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DCN28 also features USB Audio input for convenient streaming of music from either
PC or MAC. The USB Audio is fully isolated to eliminate disturbance from noisy
PC power supplies. No driver installation is required when connecting and normal
44,1kHz and 48kHz / 16 bits PCM format are supported. To sum it up, your ripped
CDs or downloads are easily played directly from the PC.
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- - - - - - - - - - - - - - - - - - - - - - - - - Audio Processor - - - - - - - - - - - - - - - - - - - - - - - -
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The heart of the DCN28 is the digital audio processor (DSP). The processor runs
at
96kHz with an internal resolution of 76bits. All sources are upsampled
by a precision Sample Rate Converter to the required 96kHz before entering the
processor. The processor is configured with 2 input processing blocks of 10
biquads each and with 8 output processing blocks of 20 biquads each. Each
biquad processing unit can form a PEQ, high-pass, low-pass etc.
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- - - - - - - - - - - - - - - - - - - - - - - - - - - Clocks - - - - - - - - - - - - - - - - - - - - - - - - - - -
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An important part of a high performance digital crossover is well planned and well
designed PCB layout. For the DCN28 all measures have been diploid to do just
this: Separation of the digital circuitry and analogue circuitry on each ground plane
is obvious. Clock tracks are as short as possible with inserted resistors between
all input/output ports to reduce peak gate charge currents. Even the other IC
interconnections have inserted resistors to reduce interaction from IC to IC.
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- - - - - - - - - - - - - - - - - - - - - Digital to Analogue Converter - - - - - - - - - - - - - - - - - - - -
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After all the processing in the DSP the data enters the 4 dual Digital to Analogue
converters equals 8 output channels. If the software setup is made correctly the
signal will have maximum possible resolution and the absolute best performance is
achieved all through the DAC and the following I/V and low-pass section. The I/V
and low-pass section features high grade OP-amps from latest generation of
National Semiconductor's specialized audio OP-amp range.
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- - - - - - - - - - - - - - - - - - - - - - - Isolated PC Interface - - - - - - - - - - - - - - - - - - - - - - -
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Optical isolation is used to eliminate noise coming from the outside and this time
it's to eliminate noise from the PC programming the setups to the DCN28. The
same PC is also used for measuring drivers. One more reason for optically
isolation is because it is important to eliminate ground loops to avoid hum when
measuring and fine tuning the frequency response while listening.
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- - - - - - - - - - - - - - - - - - - - - - - - Dot Matrix Display - - - - - - - - - - - - - - - - - - - - - - - -
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The display on DCN28 a is big easy readable Dot Matrix type with red LEDs.
The display reads out attenuation (volume), input source, EQ preset (software
programmer able), sample rate of digital input source, muting, individual channel
mute and individual channel attenuation. At Power On a small LED will flash while
the massive capacitor bank is ramped up (2 sec) followed by a welcome text.
The same LED will be lit in StandBy mode.
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- - - - - - - - - - - - - - - - - - - - - - - - - Encoder Button - - - - - - - - - - - - - - - - - - - - - - - -
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To the right of the display is the encoder button that can control all functions of
DCN28. The button can be pushed and turned to get the wanted menu point and
functions value. The encoder is a high reliability magnetic type with 40 detent
resolution. The button itself is made from stainless steel.
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- - - - - - - - - - - - - - - Isolation between Mainboard and Control board - - - - - - - - - - - - - - -
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The communication between the front mounted control panel and the
mainboard
is also isolated by use of opto-coupler ensuring no noise and
ground loops
for absolute best performance and optimal listening conditions.
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- - - - - - - - - - - - - - - - - - - - - - - - Volume regulation - - - - - - - - - - - - - - - - - - - - - - -
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The full scale audio signals from the 4 dual DA converters are attenuated in an
analogue volume circuit in steps of 0,5dB. The attenuation range of the master
volume is from -100dB to 0dB, where -100dB is the weakest and 0dB is the
strongest. Each output can also be individually attenuated from -15dB to 0dB in
steps 0,5dB. The volume circuit is high precision and controlled digitally. Note that
although digitally controlled, the regulation is still done in the analogue domain.
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- - - - - - - - - - - - - - - - - - - - - - - - - Output relays - - - - - - - - - - - - - - - - - - - - - - - - -
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All the balanced outputs are muted by fully sealed high reliability signal relays. In
front of the relays are fully balanced output buffers ensuring optimum conditions for
the volume circuit and giving low output impedance for best drive capability for the
connected power amplifiers. The output buffer uses the same National
Semiconductor OP-Amp type as the DAC section.
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- - - - - - - - - - - - - - - - - - - - - - - Balanced Outputs - - - - - - - - - - - - - - - - - - - - - - -
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The Neutrik gold plated 3-pol male XLR outputs connectors connect the true
balanced signals to the power amplifiers of your choice making high audio
performance possible. If the connected amplifier only has RCA input connectors,
you will have to use an adapter or XLR to RCA cable.
Note that the inverting pin 3 is NOT allowed to be shorted to ground (shield).
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- - - - - - - - - - - - - - - 4 pcs. Power Amplifier Remote Trigger Outputs - - - - - - - - - - - - - - - -
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DCN28 features 4 pcs DC-jack connectors (2,5mm/5,5mm) for power amplifier
remote switching. The output is 12Vdc maximum 100mA and will be able to power
a standard 12Vdc relay in the power amplifier requiring no standby power in the
power amplifier. The switch on is sequential with a time interval of about 1,5 second
to preserve the house fuses.
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DCN28 Features:
- 4 Digital Inputs (AES3-Coaxial-Optical)
- 2 Balanced Stereo Analogue Input
- 4 presets on input processing block - controlling tonal balance
- 1 USB Audio Soundcard Input (galvanic isolated)
- Digital controlled analogue attenuation on all outputs
- 4-way stereo true balanced outputs
- Digital PCM signal 32kHz-192kHz
- Optinal application code for Philips Pronto remote
- Optinal code for Logitech Harmony Remote
- Big Dimmerble Dot Matrix display
- All in one Encoder Button controlling menu and values
- 4 Power Amplifier remote trig outputs for 12V relays
- Converter Resolution 24bit
- Sample rate 96kHz
- Total processing power: 180 biquads IIR
- Frequency response: 5-48kHz (-3dB)
- Latency input-output about 1ms
- Low Standby Power
- Dimensions: 430mm x 290mm x 100mm
- Included XOverWizard II advanced software
- Included Philips SRT8215 Universal Remote
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