http://www.mother-of-tone.com/attraction.htm
http://www.jitter.de/german/ger_navfr.html
Il fonctionne sur batterie 12V
Des essais :Hi everyone,
to answer your questions:
On the Attraction DAC I use the TDA1543 because it is R2R and because it can be used with a single-ended power supply.
As you already know, the Attraction DAC is designed to be powered by a Optima Red Top 12V car battery which eliminates the need of wall powered (noisy) supplies.
I use active I/V conversion 1 OPA134 per channel, and 4 OPA134 per channel as output buffer. The DAC can power a speaker directly
The output level is as high as it possibly gets with a 12V supply, so it is
about -3.5 Volts to +3.5 Volts full scale (which btw. seemed to be enough to
overdrive DUC's preamp).
The input (spdif) receiver is custom. I programmed it into a Xilinx device. It
has a switchable JISCO option and all DACs come with the UPCI (ultra-precision
PLL) which synchronously reclocks the data.
There is 2 custom made VCXOs for the frequency generation and tuning and one
custom XO for the JISCO function.
All features programmed into the Xilinx, which was really fun, but no walk in the park, btw
The Attraction DAC runs up to 192kHz on spdif input. It uses neither upsampling nor oversampling. Just straight conversion.
So above the more obvious stuff. But why is it so damn good ?
Okay, the pcb is flat on the bottom, which means that all through-hole
solderjoints have to be flat.
There is no housing and the high-quality RCA jacks are not connected via wire, but directly soldered to the pcb.
Then this pcb is screwed on a spruce board which is the reason the pcb-bottom has to be flat.
Mounting to the spruce board adds body to the sound (which otherwise is not
there).Then there are a couple of other tricks I apply with the DAC which I better not mention here, in order to prevent some avalanche-kind of response
However, now you have something to play with ...
Fun
Charles
ALTMANN MICRO MACHINES
Quote:
Charles, have you experimented powering the OPA134s with a separate battery?
Would be easy to implement and probably would further improve performance.
I think it would mess up performance.
However, the OPAs get the pure battery current, then comes the DAC (regulated)
and then comes the digital section (regulated separately). Ground plane
separation plays an important role too among other things.
I think if anyone of you would spend 5..10 years of his life tweaking with DAC
issues - add a portion of luck - add an extra portion of ignorance - you would
all come to quite similar results ...
Charles,
Quote:
If I may ask how do you make a dual supply for the op-amp with a single 12vdc ?
Hi Will,
I feed the signal at 6V, just about in the middle.
That's the reason that the Attraction DAC has coupling caps at its output.
Charles
http://www.enjoythemusic.com/magazine/e ... ng_dac.htm
http://thehbproject.com/nl/testen/74/0/ ... action-DAC
http://www.6moons.com/audioreviews/outs ... tside.html
...mais c'est un R2R sans oversampling , leur caractéristique est d'être fluide , mais de manquer d'énergie ( je crois que c'est un de tes critères) . Les seuls qui échappent à ma connaissance à cette caractéristique est le holo Audio May ey son petit frère.
