| johnny1 |
Well...
A common question again...
Does anyone of you has ever tried this DAC? For the guys that do not know what I am talking about, it is a DAC based on the CS8414/ DF1704/ PCM1704 combination. |
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| peranders |
I have seen it and I must say it ti very well done with OPA627 (really expensive) in the output filters and also very nice loooikng pcb's with split groundplanes see http://www.diyaudio.com/forums/show...ber=2#post66938
The DAC chip PCM1704 is one of the best, the measured performance is excellent.
I have never listen to it but I have a hunch of it may be rather good.
BTW: IC10, IC12 looks weird, is the schematics right? The minus input is shorted with the output of the opamp? :confused: Can anybody explain the output filter for me? |
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| promitheus |
Hello,
I am still building this DAC but I am not finished.
The reason I started it was because it has one of the best chip sets around. The PCBoards are also very good designed with ground plane and everything. It really is worth buying them ready made. I got them from a company that makes Elektor pcbs and that are high quality.
I will use it with the Upsampler board that was published later from Elektor magazine so I donīt have to build the input board from the DAC 2000.
Also I want to use a different Analog stage instead of the op amps but I still havenīt found anything.
If you decide to make this DAC also and you live in Europe I can tell you where I got my parts. |
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| johnny1 |
Promitheus...
Thanks for the reply. As far as the analog stage try http://www.borbelyaudio.com/index100.htm
They have some fet designs that look promising.
I already have all the parts and i will have the pcb in the next few days
I will post photos.... |
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| sikkek |
Peranders,
The opamps with ouput shorted to negative input are simply buffers: the output is equal to the positive input. In a formula:
Uo = A*(Up - Um)
Uo = output voltage,
A = Open Loop Amplification
Up = voltage at + input
Um = volatge at - input
Here Um = Uo so
Uo = A*(Up - Uo)
=> Uo = A*Up - A*Uo
=> Uo + A*Uo = A*Up
=> Uo * (1+A) = A *Up
=> Uo = A*Up / (1 + A) = Up * A / (1 + A)
Because A is very lage (> 100.000), the term A / (1+A) basically equals 1, so
Uo = Up
(With an A of 100.000, Uo = 0,99999 * Up ) |
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| Edwin Dorre |
| quote: | Originally posted by promitheus
If you decide to make this DAC also and you live in Europe I can tell you where I got my parts. |
Hi I live in the Netherlands and I am still looking for a good DAC design. Everybody seems to fight about one, talk about one, but I can not find good ones. Only ones with out-dated chips which are hard or cannot find...
Can you please make scans of the DAC article and the upsampler article of the magazine and email them to me???
My email: edwind@xs4all.nl
Thank you very very much in advance,
Edwin |
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| guido |
Edwin,
Try DIL (www.dil.nl), you can get the whole DAC 2000 in parts without the powersupply (Euro 451). They have many Elektor projects (elektor/Elektuur is dutch, like DIL, yourself and me..).
If the thing is worth 451 euro, i don't know. Not too fond of elektor:
Groundpins is always an issue. I can remember elektors first dac with the PCM63. Resistor between agnd and dgnd of the DAC.
The databook however says to connect both pins together and then return them to agnd. So why elektor thought they knew better ???
Have an article from Analog devices where they explained why both agnd and dgnd should be returned to agnd (for DACs and ADCs if i remember correctly). Guess this is always the way to do it, unless the datasheet of the dac says otherwise. In the case of the old DAC of elektor, it did not..
The name agnd and dgnd of the dac pins is what they are internally connected to, not to what they should be connected to on the outside.
See what the reactions will be on the above, guess there will be some :->
Groetjes,
Guido (and no not G.Tent) |
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| peranders |
| sikkek, I'm quite aware of the basics but sometimes I can get short circuit in my brain, if yoiu know what I mean?. If I rewrite the schematics I clearly see what's all about. It's a simple 3rd order active filter, rather classic too, hard to see at first. |
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| sikkek |
Peranders,
Sorry to insult your level of electronic knowledge... I was just trying to help, so don't bite my head off! ;) |
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| Edwin Dorre |
| quote: | Originally posted by guido
Edwin,
Try DIL (www.dil.nl), you can get the whole DAC 2000 in parts without the powersupply (Euro 451). They have many Elektor projects (elektor/Elektuur is dutch, like DIL, yourself and me..).
If the thing is worth 451 euro, i don't know. Not too fond of elektor:
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Thanks,
I am looking at all opions. However I think DAC design for DIY are rather hard to find, at least good ones. As I stated earlier, most use outdated chip-sets.
My father sometimes build thinks from elektor and it did not alway work the first time (you needed 'Het Lek' to get it working!) . So that's why I wanted to see the design before looking for the parts!
Do you know a good DIY dac design?
Edwin |
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| hifi |
there is a thread in the digital section about constructing a DIY dac with cs8420 and cs43122 or any other suitable chip maybe you want to be a part of that project??
/micke |
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| peranders |
| quote: | Originally posted by Edwin Dorre
My father sometimes build thinks from elektor and it did not alway work the first time (you needed 'Het Lek' to get it working!) . So that's why I wanted to see the design before looking for the parts!
Do you know a good DIY dac design?
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Elektor designs looks very solid but occasionally you can read about bug fixes (good) but sometimes there are no bug fixes.....for the bugs.
Your last question. Not very many top modern DAC's kits are available. The only serious one is the one from Elektor. Anybody who knows more about this? |
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| weissi |
| Look at ww.diyaudio.de, may be also useful..... |
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| hifi |
Norbert Beier was involved in a motorcykle accident and im not sure if the board or dac kit still is availible ??
/micke |
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| weissi |
| Why need a kit? think the layout alone could be enough if he is familiar with electronics... and the parts are very common...??? |
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| united |
| Has anyone succeeded with this project, I started building one years ago but never got round to finishing it (like many other of my projects:( ) It is next on my list when I finish the amp I'm currently working on. |
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| Bgt |
| I am using 1 for many years now, its my main DAC. I've got a lot of DAC's but this 1 has the best soundstage/depth. |
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| united |
Hi
Did you have any problems getting it to work? Mine is far from finished but any tips you may be able to give me would be useful. I may not use the same analogue section, but I've not yet got to that. Did you build it exactly as the Elektor design?
Jeremy |
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| Bgt |
| It was not difficult to build. I will take some photo's later to show you how its done. |
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| Bgt |
Some pics of my DAC2000:
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| united |
nice work Bert. Did you make any modifications to the original design?
J |
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| Jaap |
I made the elektor dac and didnot buy the opamps. Instead i connected a Tribute transformer over a 100 ohm IV resistor and it sounds very good. Before that I had a simple tube output with 6H30 tubes and this also sounded fine. Transformer is just al little bit better.
I had a conversation with a Dutch Elektuur (+Elektor) editor about my tube output at that time. The man was not amused that i raped his great design with an old fashioned tube ! "Why putting a motor of a "lelijke eend" (= old french car: Citroen 2CV) into a mercedes" he said (published in the magazine). I think he would have shot me if I had been in his neighbourhood.:smash: |
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| Jaap |
Can this design be bettered with a "superclock" ? For instance the one from Guide Tent ?
How to connect it ?:xeye: |
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| ABO |
I also built DAC200. To get the best results, the standard power supplies that are part of the design should be replaced with low-noise regulators. Especially the supply for the DF1704 is critical and also the supplies for the opamps (harshness disappears and better resolution)). I have not changed the regs for the PM1704 (couldn't hear improvement).
Further, place big caps close to the OPA's like former formum member CarlosFM championes (finally bass slam). Remove the output filter completely as this one ruims the sound.
I also surrounded the DAC chips with smd's soldered directly on the leads (improved top end).
I have build the DAC inside my old Marantz player. I'm not using the SPdif part, but I have connected the DF directly in parallel (iis)
with the existing digital filter in the player. I also use a tent clock that is directly connected to the BCK (I think) of the PM1704's.
I have also found that putting ferrites in the power supplies dramatically improve soundstage (but only for a month or so. The claims made by Charles Hansen about ferrites are corroborated by my own experience).
All in all I feel that Elektor did a nice project but it shows (again) that they know **** about audio.
Abo |
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| Bgt |
| quote: | Originally posted by united
nice work Bert. Did you make any modifications to the original design? |
Changed the opamps to THS4031, added some trimpots on the chip legs for the offset(DC coupling).
Replaced all the caps to rubycon zl's. Also placed 100uf/16v per rail/leg under the audio opamp. sockets.
Use the optical Spdiff input. Tried the coaxial but there was no difference except a tinny bit more humm/static. Sound is really nice/wide. |
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| Bgt |
| quote: | | Originally posted by ABO I also use a tent clock that is directly connected to the BCK (I think) of the PM1704's. |
what frequency? |
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| united |
I intend to take advantage of the balanced input on the CS receiver. I built a balanced output driver module which I used on my previous project.
It would be of interest to know how to implement an arrangement whereby the masterclock was in the dac, with a feed back into the transport. This is I believe the best way to get rid of jitter. |
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