Ec-Designs Multi-Bit DAC

Discussion in 'Digital: DACs, USB converters, decrapifiers' started by murphythecat, Dec 2, 2018.

  1. soekris

    soekris MOT - Soekris Engineering

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    I'm sorry, but the DIR9001's recovered clock is specified to 50pS RMS jitter typical, is that what you call "low jitter" ??
     
  2. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    youd have to ask Ec designs, im sure they will answer you! He told me some information sepcifically about his electrotos connection, but im not sure if Im allowed to share it in here. I can maybe pm you the convo
     
  3. soekris

    soekris MOT - Soekris Engineering

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    I expected you to be associated with the company, after posting all that sales crap....

    Trust me, there is nothing "low jitter" in that ElectroTOS.... To me, it seems like it's just a Coax SPDIF, connecting to a Toslink transmitter to a Toslink receiver, feeding the DIR9001 receiver, you can lever get anything good out of that as the jitter is adding up....
     
  4. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    how about you contact ec designs. you should know what kind of charachter John brown is, what your doing is just insulting. im out
     
  5. soekris

    soekris MOT - Soekris Engineering

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    Since real specifications are totally absent from Ec Designs website, I'm just trying to find some information. Sorry, if I assumed you had anything to do with EC Designs, it just sounded like that, In the future, I suggest you put a disclaimer on post like that....
     
  6. monacelli

    monacelli Friend

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    I just wish the DAC had another input besides ElectroTos. Apparently the USB is for power only. It wouldn't have cost the manufacturer much to include a normal coaxial SPDIF input. So you're left with the unfortunate conclusion that they invented "ElectroTos" mainly as a way to force you to buy their digital transport if you want to use their DAC. It is hard to get behind manufacturers who design products this way. This is the digital protocol equivalent of MQA, in my opinion. They basically say as much in their own marketing material:

    "It won't accept S/PDIF Toslink so you have to use it in combination with our U192ETL or UPL96ETL."

    I'm not trying to be harsh, and I think it's cool that @murphythecat has offered to loan the set to @k4rstar for impressions. That is SBAF in action. :bow:
     
  7. k4rstar

    k4rstar Britney fan club president

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    DACs are serious business guys
    a man's worth around these parts is measured by the jitter in his datastream

    @murphythecat maybe you can write the EC designs guy and suggest he register here to answer questions about his DAC, since he is already posting on diyaudio. I think I understand the topology now but I had to read 4 different pages to get a complete picture. it would do some good to explain it simply for people
     
  8. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    sorry if i over reacted, im not affiliated to ec desings. since your on diyaudio i think and desing a tda1541 dac, i assume you know of john brown work ethic and know that he's a seriously good engineer. if you have questions he'll be happy to answer you im sure but your previous post of yours seemed a bit out of character

    from the diyaudio thread, he mention he tested most spdif receivers available:"
    The very best performing S/PDIF receiver we found (we thoroughly tested & tweaked all popular S/PDIF receivers over and over again) was the DIR9001 with a tweaked loop filter and in combination with the ElectroTos low jitter protocol. The DIR9001 supports 96 KHz maximum.

    Higher sample rates require higher clock and data rates in source, interlink and DAC circuits. Circuits are never perfect, the major issues with digital audio are stray capacitances and stray inductances in source, interlink and DAC. The combination of high frequency clock and data rates with these parasitics will cause major issues with digital audio that are still not fixed. One of the results is source dependency (every bit-perfect source still sounds different). When clearly audible source dependency occurs, digital audio is still far from optimal.
    "
    https://www.diyaudio.com/forums/dig...ding-ultimate-nos-dac-using-tda1541a-768.html
    john brown seem to not want much more publicity, i doubt he'd come over. ill ask him but he explain his desing evolution in detail over at diyaudio: https://www.diyaudio.com/forums/dig...ding-ultimate-nos-dac-using-tda1541a-774.html
     
    Last edited: Nov 16, 2020
  9. Khronos

    Khronos New

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    I'm not affiliated with EC Designs, but based on the technical aspects that I could withdraw from John Brown's explanations on the DIY Audio forum, the DAC is actually using Dynamic Element Matching for conversion as Philips did back in the 80s with their TDA 1541.
    [​IMG]

    I believe they require both D/D and DAC to be intrinsically isolated. I would venture to guess because it's a sort of optical servo which outputs current (though I may be wrong) based on the BitStream of the SPIDF Connection (next iteration will use normal SPIDF instead of ElectroTOS, I think).

    Interesting engineering, to say the least.
     
  10. Perri

    Perri New

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    So what do you use and what is the jitter rated at on the receiver you use ?
     
  11. Beefy

    Beefy Friend

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    Without wanting to speak for Søren, there is good information out there on the Soekris DIY DACs that I can relay, that I believe is largely applicable to his commercial DACs.

    Basically, the receiver Soekris uses doesn't matter. The DAC incorporates a FIFO buffer that buffers, reclocks and resamples all incoming signals. The clock driving the system is the Si570 programmable oscillator. Without trawling 1000+ pages of diyaudio threads, best I can recall is that total system jitter is under 5ps.
     
  12. lehmanhill

    lehmanhill Almost "Made"

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    I'm not trying to speak for soekris and am not associated with either EC or soekris. Although some soekris dacs have Toslink inputs, I don't remember any that didn't also have alternative input connections. For example, the top line 2541 has 2 SPDIF, 1 Toslink, 1 AES, and 1 USB. The thing that has made EC Designs dacs unusual has been their choice of a single Toslink input when Toslink receivers do have higher jitter than SPDIF. I get that EC was enamored of the electrical isolation provided by Toslink, but the jitter issue made it surprising that they only used Toslink.

    I personally own and use an EC Designs MOS16. However, I have modified it to have an RCA input in parallel to the Toslink receiver. However, this doesn't work with normal SPDIF sources. I am lucky to feed it with a Pi2designs 502dac RPi hat that is able to send SPDIF at 1 volt which is acceptable for the Toslink receiver chip in the EC MOS16.

    The reason that I bring up this mod is that the MOS16 sounds noticeably better over SPDIF than Toslink. Whether that is jitter related, I can't say, but that is one likely reason.
     
  13. soekris

    soekris MOT - Soekris Engineering

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    I don't have a separate receiver, the FPGA handle it all, and as said earlier, the audio signal goes into a fifo buffer and gets reclocked by a digital PLL. The result is just the oscillator jitter which are specified at typ 0.62 pS.... One thing you should remember is that R-2R DACs are not as sensitive to jitter as DS DACs, the 50 pS jitter might be overshadowed by other things in the EC Designs MOS16. Other manufacturers are busy pushing femto jitter and other marketing slogans, but I'm very comfortable with the jitter in my DACs.
     

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