| gravir |
Thanks!
But I prefer to bulid that schematic I linked, I'd like to use more than one DAC, thats why the schematic made by Pozzoli looks good. |
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| andjules |
I remember reading a little about these a while ago...
can someone refresh me on why multiple dac chips is such a good idea? |
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| ble0t |
By paralleling the chips, you can decrease noise and non-linearities (which are at different points for each chip). Think of using a water filter, and running the same batch of water through it 4 times instead of just once...chances are you'll have 'cleaner' water :D
Also, it improves the ability of the DAC to drive longer interconnects if you have them. |
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| audionut |
Look up Doede Duama or search for dddac 1543 on the internet
Doede has boards chips and clocks...you can build an 8 parrallel 1543 for around $100 |
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| gravir |
Nobody built this DAC?
I'm too lazy to draw it...:-)) But it seems I have to... |
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| Rhinobirds |
hello gravir,
I build this dac a few months ago, well, actualy finished it a few months ago.
I started out when it was publiced at the TNT-site but through the process of building it, I changed the configuration.
In the end I did not build 3 different PSU's but only two. One is supplying 12V which feeds all the TL431 for the 5V logic. The second one is running on 8.6V and is supplying the four TDA1543's.
Lateron I also added reclocking which is worth to implement. I used a Tent clock and a 74HCT174 to reclock all the lines. The only thing I like to change are the output caps which are now some WIMA MP3's coming from an old PSU...
I build the whole thing on breadboard and hard-wired it myself, no pcb used. It takes some more time but it's not too hard to do.
At the moment I'm thinking of building different (active) output stages as posted by Rudolf Broertjes e.a. to compare them. There seems to be some pro's and con's (soundwise) but it's best to find them out yourself.
So I wish you good luck with building this baby, unfortunately I don't have any pictures (yet) to show you how I build it but if I do, I'll post them here.
Chris
P.S. I noticed that during 24 hrs my supply voltage for the TDA is not realy stable... it shifts some 0.1V during the day which makes it impossible to adjust to an exact 8.8V. Anyone had problems with this too? I build the PSU as described at the TNT-site. |
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| Giorgio |
Gravir
sorry, no PCS available from me too.
Rhinobirds,
the voltage should be around 8.8 for best performance. it is not a issue if it goes down to 8.7. Can be an issue if goes over 8.9, it is the AMSOLUTE MAXIMUM RATING for the chip, and even though apparently there is a little margin, be very very careful....
Having four DACs in parallel reduces noise, but has some not positive effect on treble. However, to have 4 in parallel in Convertus also allows to spare an output stage with gain.
Giorgio
(giorgio@tnt-audio.com) |
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