Ec-Designs Multi-Bit DAC

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

  1. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    Interesting. I assume your optical source for the MOS16 is also the 502?

    I am very curious to see if you find the coax connection to sound better than optical. Very convenient all you have to do is mess with a jumper!
     
  2. lehmanhill

    lehmanhill Almost "Made"

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    Yes, the optical source was also the 502.

    I'm curious too. So far, the coax is making a good impression, but I want to wait until I can do back to back, sorry not blind, comparisons.
     
  3. lehmanhill

    lehmanhill Almost "Made"

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    I have had some time to compare the optical and coax feeds of the MOS16.

    Optical vs Coax evaluation of EC Designs MOS16

    This evaluation was done with the same setup as listed in post #66 of this thread, with one exception. That is a Pi2Design 502 DAC was used as both optical and coax source. The 502 was used in 1 Volt coax signal position so that the MOS16 could read the signal.

    With back to back comparison of the optical vs coax input of the MOS16, it didn't take long to conclude that I much prefer the coax over the optical. Using the optical, the MOS16 is a nice dac with good performance at its price, but the coax is a simple modification with such useful benefits (assuming that you can feed the signal at 1 – 3.2V instead of the standard SPDIF of 0.5V.

    • Comparing the optical to the coax, the optical has a light haze over the music across the frequency range. As the frequency goes up, this haze gets worse.
    • With the optical, the harmonic decay of instruments seems covered by this haze. The coax conveys the natural harmonics of the instruments with their smooth decay
    • With less haze, the background of the coax seems blacker.
    • Although the optical provides a good image, comparable to the coax, image depth is compromised. The instruments feel a bit like cardboard cutouts on the optical, where the coax gives better depth and the instruments feel whole and well rounded.
    • Although minor, there seemed to be an improvement in inner dynamics with the coax.

    MOS16 coax vs Metrum Flint coax

    Now we are getting down to pretty small differences.

    • As before, the image of the Flint is closer to the listener than the MOS16. Both have similar depth of stage with the MOS16 having a very slightly wider stage.
    • As much improved as the MOS16 coax over optical for background noise, the Flint is just a bit better. In direct comparison, you can just tell that the MOS16 has a hint of a veil over the music. The result is that the Flint has more clarity and presence.
    • The clearest difference is that the Flint has better dynamics and bass with more slam.

    Overall, I personally still prefer the Flint, but I'm happy with my MOS16 purchase. Without the nuances of a direct comparison, the MOS16 coax sounds very nice and will work just fine in the project that it was purchased for. Of course, the Flint is about $200 more than the MOS16, so for those that can modify their way into a coax MOS16, it represents good value.
     
  4. lehmanhill

    lehmanhill Almost "Made"

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    I was curious about the output voltage of other coax sources. The only one I have on hand is a DIYNHK USB to SPDIF board. I took a look at its output and it was surprisingly high at 3.2 Vpp. As expected, when used to feed the MOS16 coax, it played music very well.

    If someone was interested in converting the MOS16 to coax, the first step would be to measure your SPDIF source. The quick and dirty way to measure is to measure the AC voltage at the SDPIF source with no music playing. If my math is correct, the AC voltage you measure divided by 0.7 will be approximately the peak to peak voltage of the square wave. It looks like anything above 1 V and below about 4 V should work as an input to the MOS16.
     
  5. Baten

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    It looks like ecdesigns have completed their ElectroTos novel transport and Fractal DAC. Both seem to use things that have never been done before, the fractal DAC supposedly uses a fundamentally different conversion method for digital audio that has not been used before. Sure wonder if they're any good!
     
  6. roscoeiii

    roscoeiii Acquaintance

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    Pleasantly surprised to see that the new DAC will only be a bit above 600 Euros.
     
  7. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    I dunno, looks like a lot of obfuscation and marketing. Maybe there's more tech info we could gleam from the diyaudio forums.

    I don't believe parallel input DACs are particularly new thing. Now, I don't think it's common for audio, but the 16-bit ICs used in the Modi Multibit and older Bifrost MB have parallel inputs, if I'm thinking of the right thing. I recall Jason and/or Mike talking about how it was a bit tricky and weird coming up with a way to get the usual I2S signal converted to output all bits at once.

    Again, this is assuming I'm thinking of the same and/or right thing.

    Otherwise, 32-bit fractal converters means absolutely nothing in and of itself. I'm curious to know more of the technical stuff, but it just seems fishy.
     
  8. roscoeiii

    roscoeiii Acquaintance

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    Yeah, I don't have the technical background to judge the specifics, but I had a similar reaction to the tech descriptions they provided.
     
  9. Baten

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    It does seem fishy.. but it seems to be something ec-designs has been working on for a long time I would give it the benefit of the doubt. If no one else jumps on these I might give them a try (once this whole corona thing is over and done with).
     
  10. purr1n

    purr1n Desire for betterer is endless.

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    With a ladder DAC, all the bits do need to be input in parallel. A serial to parallel conversion needs to happen somewhere.
     
  11. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    Isn't this commonly handled in the IC itself? AD5547 example being one that has actual parallel input pins.
     
  12. purr1n

    purr1n Desire for betterer is endless.

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    Yes, in the chip. But the thing is that we are talking about discrete ladders anyway for most of today's R2R implementations. And in terms of digital transmission, it's usually serial, e.g. coax, optical, USB, SATA, whatever, etc. Unless it's your old printer's parallel port, if you 'memba those on your IBM XT and Okitada dot-matrix printers.
     
  13. TheIceman93

    TheIceman93 El pato-zorro

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    Their headphone amp sounds interesting. The design seems a bit whack though. You plug the headphones into the back and it needs and external volume control? Weird.

    https://www.ecdesigns.nl/en/blog/shpb10
     
  14. hykhleif

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    greetings can I ask if the new DA96ETF dac works with roon fine, as some reported issues such as playback issues
     
  15. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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  16. k4rstar

    k4rstar Britney fan club president

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    so the transport is USB in and coaxial out right? I can compare it to my tube-based USB converter too. i am more curious about the transport than the DAC, it is fairly affordable

    the DAC worries me a bit with no output buffer
     
  17. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    the transport is definitely usb in, and from what I gathered its coaxial out.

    I wonder if there's a cable that exist that is coax (Rca) on one side that ends into toslink
     
  18. monacelli

    monacelli Friend

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    I think the manufacturer's intention is for you to use the other output of the U192ETL, which they call "ElectroTos", to feed the DA96ETF. The coaxial SPDIF output of the digital transport appears to be there so you can feed DACs that have a coaxial input, which the DA96ETF does not. That's got to be the point of selling the transport as a companion for the DAC, right? Otherwise they would have given the DAC a SPDIF input.

    From the DAC product page:
    Discrete, ultra low noise multi-pattern fractal DAC with ElectroTos input.
    Note
    : the DA96ETF does not support standard Toslink protocol, it will only produce noise when attempting to drive it with standard Toslink sources. ​
     
  19. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    https://www.ecdesigns.nl/en/blog/u192etl
     
  20. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    "
    U192ETL:
    Connections,
    Large USB-B -input- socket that connects to the PC/streamer
    RCA -output- socket that drives our novel ElectroTOS interlink. U192ETL supports 44.1/16 ... 192/24.
    Protocol (the way data is sent over the same interlink),
    S/PDIF protocol, red jumper removed. The U192ETL outputs -standard- S/PDIF protocol that works with existing DACs.
    ElectroTOS protocol, red jumper installed. The U192ETL now outputs ElectroTOS low jitter protocol over the -same- ElectroTOS interlink. As the name implies it will reduce jitter in source, interlink and DAC.
    Technology: XU208 XMOS processor, asynchronous feedback, low jitter audio clocks. 20MHz noise band limiter blocks part of the PC + XMOS noise spectrum. Multi-stage synchronous re-clocker with unique anti-ripple logic (based on edge discriminator circuits).
    3V3 ultra low noise regulator for clocks and I/O, 1V HF SMPS for 1V core voltage (greatly reduces USB bus power consumption)
    "

    DA96ETF:
    Connections,
    Large USB power supply socket for external 5V power supply only, so this is the DA96ETF -power- connector. This way one can tweak with different power supplies. Suitable linear power supply comes with the DA96ETF.
    Large (square) Toslink socket for the ElectroTOS optical plug. It only accepts -ElectroTOS- low jitter protocol, it won't accept S/PDIF Toslink so you have to use it in combination with our U192ETL or UPL96ETL. DA96ETF accepts 44.1/16 ... 96/24.
    Two RCA -output- sockets, black = left channel, red = Right channel. Output voltage 3V6pp (peak to peak), 1.27V rms (root mean square). Output impedance: 375 Ohm. There are only digital switches, power supply and resistors in the signal path. No Op-amps, no coupling caps, no tubes, no transistors, no JFETs nothing. One could call it a "passive" DC-coupled output. The output signal is directly taken from the Fractal resistor array.
    Technology: DIR9001 ElectroTOS receiver, 64 bit data bandwidth compressor / SIPO, 100KHz band limiter for additional noise spectrum attenuation. Fractal D/A converter technology, completely different from R2R. We use 4 fractal segments of 7 bits each, advantage of fractal converters are low output impedance, high accuracy, low glitch and a switching spectrum that's more "ear friendly"compared to the typical switching noise spectrum generated by (segmented) R2R ladder DACs. The Fractal converter has a true parallel data interface that offers lowest practical digital interface noise injection.

    The ElectroTOS interlink and ElectroTOS low jitter protocol.
    ElectroTOS is a combination of an electrical (coax) interlink with an LED on the DAC side that shines into the Toslink optical receiver in the DAC. The Optical receiver is a standard Toslink receiver.
    In order to drive the LED we need more than 500mV (coaxial signalling voltage). So we use 3V3 instead. the 3V3 electrical S/PDIF signal is connected through a RCA connection.
     

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