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Pure DSD - The USB DAC converter
without a DAC chip
Jan 2016 -
INTRODUCTION
Update Nov. 2016: After many test I was
not able to completely eliminate the digital noise
on
output also using separated power supply for the Amanero and also using
isolator on I2S bus so I don't suggest this project.
The
DSD signal can be directly used to reconstruct the original analog signal
with a simple RC filter.
This method allow to create a very simple DAC
without a DAC chip with sonic performance near to normal DACs.
At
this time there is only a commercial product using this method to convert
digital signal to analog output by LampizatOr (see
review).
The output wave have a DC component of 1.65V
present only during DSD playing so with a normal firmware if you change
track or click pause a high bump will be reproduced on loudpseakers.
I have an active collaboration
with Amanero srl so I
have request this new firmware that keep an empty output signal any time
there is not DSD signal to reproduce.
Using this software there is a
bump only at the switch-on and switch-off but you can add a relay to
eliminate this problem.
This DAC work only with DSD but you can
play any PCM tracks converting these in DSD with some setting on your
JRiver or
Foobar2000 player while this playing.
There is a big benefit to
convert tracks in DSD also using a normal DAC DSD converters (Korg
document , Archimago's Musings ).
I suggest to use PC with Intel® Core™i3 min and a RAM 4Gb but also on
some Android device the convertion should work with
Onkyo HF Player .
USB to DSD module
+ Firmware DSD only + passive filter
It is very simple the connection with Amaero module but you can see the
complete datasheet whre are indicated the pins (datasheet).
 |
To eliminate the noise coming from the PC power supply
cut the wire on pcb near the USB connector and use an external 6-5Vdc. Also 3 x 1.5V batteries could be used. I have add a 220uF 6.3V Sanyo OS-CON capacitor on 3.3V output pins. |
Firmware DSD only
I have an active collaboration
with Amanero srl so I
have request this new firmware to eliminate the bump during the switch tracks
and stop.
3) When you replug the erased device, Windows can ask about a driver so acept
this.
4) Be sure to be connected to internet.
5) Run ConfigOEM118.exe and after the choice of CPLD and CPU firmware press the
relative Flash button.
6) When done close ConfigTool.exe and Unplug the USB Cable.
7) Replug the USB cable and if it's all ok the audio driver needs to detect the
device.
JRiver configuration
JRiver is a
Media Center software able to play any PCM and DSD format including
SACD iso images.
Foobar2000 configuration
The Foobar2000 is an advanced freeware audio player for
the Windows platform.
It is necessary download some components to add to the
normal installation, these are auto install parts or .dll to insert in the
components directory.
Measurement
Simulation
