Via Cairoli,111/116
I-27010 Albuzzano (Pv) Italy EU
Tel. +++0382.484165
Fax +++0382.481021

D I G I C O D E   2.2 0    i n   d e t a i l

Digicode is the name of all our digital to analog convertor.
First model was build in 1992 : multibit d to a convertor by 16 bits / 4 time oversampling filter and class one digital spdf receiver, output stage by two double triode (one ECC-83 and one ECC-81).
Digicode was built in one chassis with internaly power supply,one spdf input and a pair of analog output.

Digicode 2.18 was the second generation of our tube dac (1997).
This second up-to-date convertor was designed for high flexibility, modular  pcb-board solution, externaly power supply for better s/n ratio.
Very close with our philosophy: class one spdf and aes-ebu receiver, mulbit dac AD-1865 (hi-resolution 18 bit) digital filter with low taps (near to nonoz theory) set-up decision by customer's by internaly dip-switch.
Two tubes on signal path now all ECC-81/12AT7, passive I to V converter.Great sound!

Digicode 2.20 is our actual model of hi-resolution D to A convertor.
As very close of 2.18, the model 2.20 adopted two mono Burr Brown PCM-63 convertor for 20 bits
resolution, around the PCM-63 is build a low level linearity circuit for better resolution for little audio signal near -70 db, so the little information of audio spectrum, Digicode 2.20 reproduce without hide the music detail.

D I G I CO D E--2.20 description and design

Digicode 2.20 is our reference Dogital to Analog convertor for 20 bits resolution.
The DAC is build with two separate chassis: main house and power supply with three power transformer.
Digicode 2.20 can accept three type of digital signal: SPDF by RCA connector, SPDF by BNC connector and AES-EBU by XLR connector. Out signal: pair of hi-quality RCA unbalanced output for analog signal at very low impedance.
The main house of convertor use three separate board:

  • Digital input receiver and digital filtering ( with dip-switch configuration)
  • DAC board with two PCM-63 Burr Brown convertor (with MSB/LSB trimmered tuning set-up)
  • Tube output board with two hi-grade ECC-81/12AT7 just only one capacitor on signal path.
The power supply box have three power transformer: one for every board, single board have independent power transformer, reduce jitter and digital noise.

Digital input receiver:
This board accept digital input signal as SPDF or AES-EBU. The input digital signal is coupled by special low noise pulse transformer.
The IC receiver have good eletrical performance but we have design a new PLL filter drive a XTAL
oscillator by hi-precision quard device,this solution reduce the jitter at very low value (20pps).
The digital filter perform by user two possibility of set-up as LOW TAPS or HIGH TAPS ( taps is the
coefficient number of samples can introduce the digital filter). LOW TAPS can work the filter at very close performance as "nonoz" solution ( zero oversampling filter) the set-up is by dip-switch so is possible to chance as preferred sound perceived.
All power supply regulator on this board have special design, they are all SHUNT regulator device.
SHUNT regulator supply a very low impedance sources ( less off  0.2 ohm) so the power supply close it's ability to produce invasion on sound quality of active device.

DAC board:
The new dac board use two PCM-63 multibit R2R dual mono 20 bits resolution.
We have introduce on this board some news design solution as the SHUNT regulator power supply (four independent power supply) and a tuning trimmered set-up for to reduce the waste of bits for unprecision dac low level operation.
The set-up of MSB/LSB is trimmered in the factory and don't need to recalibrate in the future.
This solution provide a very high precision resolution at low level dac area down  -70 db (usualy the sigma delta dac have resolution at  -30db!)

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