Asynchronous USB to simultaneous data converter board, interest check

Simultaneous data protocol, as used in the Model S USB, has generated significant interest among TDA1541A fans during the previous years. Also, since Model S MkIII and AYA II 2014 / DS DACs release, I have received numerous questions about possible sources that can output such a protocol.

Apparently, it is the time to seriously consider to design and release adequate device. And since PC is a major audio source these days, asynchronous USB board with such output should hopefully address most of those requests.

The idea with this unit i.e. board is to include everything that is necessary, so up to 192 kHz compatibility, galvanic isolation, two oscillators, and reclocked output. The board would need one transformer secondary (8-10 VAC) to supply its clock and output circuits. (It is of course not recommended, even though it should be easy to wire the clocks and output circuits supply from USB V+ too.) With U.FL output connectors, this board would be an adequate companion to AYA II 2014 or DS board, and of course the great possibility to connect PC to Model S MkIII.

Due to the major use of SMD parts, some of them being not any comfortable to solder by hand, the board would be shipped only fully populated. The only option would be related to firmware, so it can alternatively enable more common I2S or S/PDIF output.

We need at least 50 ordered boards to make this project actually start. Target price is 180 EUR, with the possibility to drop a bit if quantity increases.

You can expect the most definitive information about this project in June or July, and actual release some time in September.

You can however already subscribe, so we have a better picture of actual interest in such an item. Once the project actually starts, you will be notified by e-mail, so you can complete your order.



22 Oct 2016 EDIT:ย This project will be released during November 2016. You can find further information and place an order at this page:

USB to simultaneous data (or I2S) board



15 Replies

  1. Martin

    My friend Klaus uses your Aya and I am deeply impressed by its (your engineering) performance.
    Is there a chance that you will make a fusion of your Model S and Model S USB?
    Could I supply you with naked Vishay resistors for UI-conversion?
    Best regards from Vienna!

  2. Pedja Rogic

    Thanks, Martin.

    There are no plans for such a fusion. However both the Model S MkIII and this board were meant to help Audial DACs being more versatile, and since this board will be similar to the input stage of the Model S USB, using the Model S MkIII and this item connected to its PCM direct input would be, practically speaking, quite close to it.

    Yes, you can send your favourite resistors, and they will be installed.


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    great idea!

    whats about adding a inverse data output to supply a symmetric tda1541 assembly? and a i2s input not only usb ๐Ÿ™‚

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    Well yes, inverted data lines are not hard to add, so it can be done.

    However adding I2S input would require somewhat different design.


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    Hello Pedja,

    Which Crystal/clock for the asynchronous task will you choose ? NDK, Crystek, programable ?

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    Likely can oscillators, but probably none of these you mentioned. ๐Ÿ™‚

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    Nice to have this direct capability.
    On the other hand,
    It would be very nice if the new Simultaneous mode board would have the TDA1541 socket and wired up to the processor or isolator, (able to go even up to 192 kHz). Why need a separate board? Would give interference problems all over again. . .

    With all those loose components (i.e. WaveIO, Ian PCM) I have system integration problems I cannot tackle and have not the skills for. I’m afraid even two boards is too much (a reality check. . . after several stopped projects)

  8. Avatar

    I am sorry but I have no plans for such an integrated async USB DAC board in DIY shape, at least not at this time.

    It should be easy to connect two boards though.


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    What about driver support? Would it requier special drivers to be installed or can it work with native windows drivers? I do not fully understand the firmware side: do simultanious mode / I2S / spdif need each a different firmware to be loaded? Regards.

  10. Avatar

    I owe an apology to everyone for problems with this website outages and e-mails you may have sent during the previous week. The problems were caused by DDoS attack to the host data center. On Thursday evening we migrated the site, so the problem is now resolved. Apart for being inaccessible, attack did not cause any other damage.


    Windows still does not support USB Audio Class 2.0, so dedicated driver for Windows XP/7/8/10 will be provided. I am still not sure about the way the alternative firmware would be installed. There are still two or three options, and it will be decided during the next month or so.


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    Will there be a set of USB drivers made available for OSX? Or is there a chance it will be natively supported?

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    Mac OS X supports it for many years now (officially since version 10.6.4), just as Linux and Linux based audio operating systems (such as Daphile, or recent Euphony) do.

    Why Microsoft, who actually participated in setting this standard back in 2006, still does not implement it in Windows, is not known to me.


  13. Avatar

    I have AYA I model DAC so would like to know if its possible to add this module to my DAC?
    If I understood correctly this mod will give me ability to play high-res files (up to 192khz? )
    Is it difficult to add to existing unit?
    Just for fun I have added an XMOS USB module to my dac ( simple solder) so would like to know how and do these can work together?
    Im not sure what all this is to be honest but I am interested (and bored ๐Ÿ™‚ ) in adding anything that I can to this great DAC.
    Or, in a few words can you explain what is main purpose of adding this board?
    Thanks and sorry for being a complete noob


  14. Avatar

    Hello Steph, and welcome to

    Basically, this item will do the same task as your XMOS USB module, by connecting PC USB port to D/A chip. You will be able to connect it to any previous TDA1541A DAC I designed, of course provided you can make a physical connection at all (only AYA II 2014 and DS, and Model S MkIII have ready available connectors) โ€“ and if you managed to connect XMOS, you will not have a problem to connect this board either.

    The difference with regard to the board you already have is that this board can output simultaneous data protocol, which is preferred mode of operation for TDA1541A (I2S will be available as option), and it will include better clocks and galvanic isolation, and balanced output. And yes, as stated above it will work for up to 192 kHz.


  15. Avatar

    Now it is official: we will go with this project, and the offer is now definitely open, so you can place an order.