AYA 4: This year’s AYA release, featuring 192/384 kHz async USB

AYA release scheduled for this year is coming. We will call it AYA 4, and number increment came from its completely changed USB stage, which is now no-compromise, asynchronous USB, a 192 kHz (with 11.2896 / 12.288 MHz clocks) or 384 kHz (22.5792 / 24.576 MHz clocks) capable.

As such, AYA 4 is stereo DAC, based on TDA1541A, but its USB input stage can be made as four channel interface too, and in this case two channels D/A conversion is performed by on-board D/A stage, whereas two more channels are forwarded as digital output to U.FL connectors, for D/A conversion by another board.

Yet, as opposed to the USB stage, which is completely changed and now all SMT, AYA 4 will keep the same D/A and output stage of AYA II, so they remain DIY friendly, and DIY manual for these parts will be provided. An S/PDIF stage will be slightly revised, and it will have a bit more SMT parts than AYA II had, but anyone able to put together S/PDIF stage of AYA II will be able to do it with AYA 4 as well.

AYA 4 transformer will be also slightly different than AYA II transformer, since AYA 4 requires one additional 8 VAC secondary winding.

AYA 4 board size will be somewhat increased too, and at current state of the design its dimensions are 180 mm (w) x 160 mm (d).

And, just as AYA II 2014 and DS, an AYA 4 will be also produced in limited, one-time series. Lead time will be three weeks for unpopulated PCBs, one month for partially (USB stage only) or completely populated modules, and two months for completed devices.








18 July EDIT:

Ordering buttons are removed, and manufacturing process has been started.

Please use the contact form to check for possible surplus items.



PCB: €35 each plus €15 shipping (charged once)

Printed circuit board comes with no parts installed. Assembly manual is provided, but please note that this manual does not provide details about the USB input stage.


Modules: €190-€610, several options available, €20 shipping costs are charged once

“Module” means partially or completely populated and tested board. With transformer, chassis, and chassis mounted connectors and switches, module makes fully operational device.

Module can include both USB and S/PDIF input stages, or only one of them, or it can have no input stage at all (so only D/A and output part). Any AYA 4 module however has two inputs anyway, and PCM / I2S direct connection (U.FL) is available instead of any unused input stage.

Additionally, a module that includes pre-fitted only USB stage is available. USB stage is all SMT, and not convenient for hand soldering, and details about this part are not included in the assembly manual either. That is why those intending to use USB are advised to purchase the module that includes populated USB stage.



Transformers for AYA 4, €60 each, shipping included

Each transformer includes one 8 VAC, six 9 VAC, and one 16 VAC secondary winding.

Isolation transformer is offered as optional device. It provides mains filtering and so-called balanced power.



AYA 4 completed unit: €850 plus €30 shipping

Ready made D/A converter with S/PDIF and async USB inputs, in usual Audial chassis, most similar to that of AYA III.







Related topics:

Another story about TDA1541A: 384 kHz

OPA861 output stage for AYA II

AYA II DS, DIY edition

AYA II 2014 DIY edition talks

31 Replies

  1. 02-07-2018

    Hi. If I ordered the module USB input only, do i get the pcb with the rest of the dac as well?
    I still have my previous AYA-II DIY DAC transformer, can I still use it if I simply add an other small 8vac secondary transformer?

  2. 02-07-2018

    Hello Sylvain,

    Sure, all modules use the same AYA 4 board, and difference between them is in pre-fitted parts they include.

    So the “module with USB input stage” includes pre-fitted USB stage, and you can normally populate the rest of the board by yourself.

    And yes, you can use separate transformer for additional secondary voltage.


  3. 02-07-2018

    Great, I’m hooked again, I’ll press the order button in a few 😉
    Thanks for this great opportunity, SB

  4. 02-07-2018

    Payment done. thanks

  5. 02-07-2018

    Confirmed. Thank you, too.

  6. 02-07-2018

    I’m guessing I’ll receive the documentation by private email once available?

  7. 02-07-2018

    Manual will be either sent by email, or available for download, along with Windows driver, which is executable, and hence usually refused by many email servers. But you will be notified by email for sure.


  8. 03-07-2018

    Good morning Pedja, would you mind trying to talk a bit about the effect of the isolation transformer. Mostly I am interested in the sonic difference.



  9. 03-07-2018

    Good morning, Ernst.

    This is still somewhat controversial topic in audio. Some swear to hear no difference, and some claim the isolation transformers steal dynamics, “even if they use highly oversized unit”.

    The difference is in details (or if they do matter then they are not details?), and results depend on the actual environment (mains voltage, the rest of the system), and how the transformer is done (actual unit, physical set-up etc.). You can consider an isolation transformer as any other (mains) filter, and expect the same or similar effects, but you should be careful with transformer external dissipation too, especially with EI unit.

    When working with supply filtering, I always pay attention to the dynamics, background, and tone (pitch, color).

    As you might know, I still use the isolation transformer in Audial S DACs. It is made in a way it makes no harm, while benefits may differ in different system and places.


  10. 04-07-2018

    I’d like to ask about some details of the usb stage.

    Is the usb stage kind of implementation of XMOS/Amanero modules ? – so there are some custom made BGA chips that couldn’t be mounted in future? If not, could be even a simple partial schematic screenshot provided later for those who have access to SMT assembly workspace?

    Is the data to simultaneus data mode conversion possible only in the USB stage or is done later, so connecting external I2S signal, or by the SPDIF can also feed the DAC with the simultaneus data?

    Is the USB receiver stage designed like a separate module, that could be for instance disconnected and used in a different DAC project?

    And lastly, what are the demands for the wattage/amps for the lines of the trasformer; is for example 1 Watt for each enough?

    Thank you very much for explanations in advance 🙂


  11. 05-07-2018

    Hi Pedga,
    Can AYA 4 transformer be used with AYA II 2014/DS boards?

  12. 05-07-2018

    @ Bartek,

    AYA 4 is one PCB device.

    There are several reasons why USB stage is not intended for DIY, and hand-soldering difficulty, as serious as it is, is actually only one of them.

    USB stage decoder is programmed to output simultaneous data protocol (but it can output I2S too, on request), while S/PDIF uses off-the-shelf receiver, with I2S output. U.FL I2S/PCM input carries the signal directly, as is, to TDA1541A.

    There is no reason you can not use AYA 4 USB stage with other D/A unit.

    A current required by all lines is up to 60 mA, apart from 8 VAC, which takes up to 120 mA. In my view, a 0.5 A and 0.8 A (respectively) capable secondary windings are fine.

    @ Boris,

    Yes, it can. It has one secondary winding more, but it is no problem to leave it floating.


  13. 06-07-2018

    Hello Pedja,

    This is really neat.. I’m curious on how you switch from USB input (simultaneous data mode) to SPDIF without using a dipswitch near the TDA1541A.. Thanks!


  14. 07-07-2018

    Thanks, Frederick.

    AYA 4 has one more relay than AYA II, to switch between two modes. But DIP switch footprint is still there too.


  15. 13-07-2018

    Thanks Pedja..

    It’s cools thst you have a found a way in switching between input sources with no or minimal compromise in performance.

  16. 16-07-2018

    Hello Frederick,

    Basically, the choice here is between relays and logic circuits. They both have their own advantages and shortcomings, and in this case I found relays more practical. On the other side, to switch between two clocks in the USB stage I am using the multiplexer.

    Regarding TDA1541A mode selection, the same approach was used in the Model S Mk3. It takes a few centimeters of traces to get that mode selection relay connected (or that’s what I managed to do, among the other stuff there), but there is no compromise in this, not the sonical one I can hear.

    So, in the AYA 4, the TDA1541(A) mode can be set either by the wire jumper, the PCB DIP switch, or by the relay. Also, AYA 4 will be able to accept either protocol at either U.FL input (AYA II could accept I2S also at either U.FL input, but only the first set of U.FL could accept simultaneous data protocol).


  17. 16-07-2018

    And here is how AYA 4 PCB looks alike.

    Ultimately it is 187 mm (w) x 155 mm (d), so the area roughly 30% bigger than AYA II. At left, you might notice the USB stage very similar to Audial USB interface board, and at right something very similar to AYA II D/A and output sections, with S/PDIF stage now above (or behind). In a nutshell, that is what AYA 4 is, but some features make it still more than the plain sum of these two.

    (Click on the picture to enlarge.)



  18. 29-07-2018

    can I order the aya 4 with pcm/i2s input and spdif input?

  19. 29-07-2018

    I mean can I order the compete AYA 4 with SPDIF and PCM/I2S input with chassis

  20. 30-07-2018

    Reply sent by email.


  21. 01-08-2018

    Are orders still open for this?

  22. 01-08-2018


    Online ordering is not possible anymore, and the manufacturing process is underway. There will be however still some spare samples, and at this time it is best to send your request by contact form.


  23. 01-10-2018

    Dear Pedja,
    If using two transformers to provide power to analog and digital parts individually, will improve sound quality from AYA4?

  24. 01-10-2018

    Hi, when the pcb is expected to ship to us? Thanks

  25. 01-10-2018

    @ Arthur:

    Speaking at most practical level, I must admit that I’ve never tried this particular option with AYA II, III or 4, however I wouldn’t expect any improvement. I was however playing with different transformers setups before, and I found myself preferring to have all the necessary windings at one transformer, whenever possible.

    Also, please note that some circuits in this DAC are purely analog (output stage), some are mostly digital (USB and S/PDIF), and some are real mixed signal (D/A part). “Mostly” means that you can consider the clock at USB, and PLL at S/PDIF stage rather analog than digital in nature, even though they operate high frequencies, so it is not always easy to make a clear distinction between the analog and digital side.

    @ Sylvain, and everybody:

    Yesterday I’ve sent an email with this information, so please check your inbox(es) or spam folder(s), in case you missed it.

    We are just starting to ship, and the orders without USB stage will be probably all shipped this week, while the orders that include USB stage will probably start shipping next week.


  26. 08-10-2018

    Hi, Pedja
    A couple of questions that came to my mid, reading the AYA4 assembly manual:

    1. Will be possible in the future to replace the master clock (by ourselves) to the 2x higher/lower rate clock (resoldering the clock with some selection in the firmware drivers)? – I’d like to try listening upsampled to 384kHz – but maybe I will end up with listening no-over/upsampled 44.1, or maybe upsampled 192kHz with slower clock will turn out to be optimal..

    2. Would be possible in the future to switch the USB module output to I2S or PCM mode output for usage with other Dacs?

    3. Shouldnt we select by even some jumper the frequency division rate, so that for both USB – 32bit frame and SPDIF-64 bit frame, we would still preserve the 4xFs DEM clock? Is intentional to clock the DEM with 88.2 khz with simultaneus mode? (As I remember from the TDA detailed documentation, the 4xFs, i.e. 176.4 was optimal, the deterioration of the signal started very slowly to rise above this frequency.., but it the other hand we’d like to have the dem clock as fast as possible to improve DEM cycle averaging accuracy, so also not lower than 4xFs)

    4. Do you have any opinion of using higher capacitance DEM decoupling capacitors (preserving their same high quality, even to uFarads, eg 4.7uF)? Or all 100nF are optimal by your experience?

    5. What do you think about employing additional so-called level matching of the i2s lines (operating with switching levels very close around the input L/H threshold), to reduce the switching noise, and even filtering by small cap to gnd?

    6. What do you think about driving the DEM differentially (both COSC pins, symetrically with Q and nQ) for example with the divided clock passed through some DFF clocked with the master clock?


  27. 09-10-2018

    Hello Bartek,

    1. Yes, it would be possible.

    2. This would be possible too, however the AYA 4 USB input stage was meant exactly like that, i.e. as an input stage for AYA 4, even though it has additional optional feature to send two more channels out to the other D/A board. However it was not meant to serve as a standalone USB interface.

    3. TDA1541A THD+N performance slightly decreases as DEM frequency goes above 250 kHz, but it is not that huge, as you can see from the attached picture, originating from the old Philips papers.





    On the other hand, I found no problems with low DEM frequency, down to 80 kHz. Having said this, and having to take the BCK (and not master clock) as a basis for DEM clock, I settled on the scheme you see in the AYA 4 (and AYA II DS), which works with sources between 44.1 kHz and 384 kHz, and quite consistent performance in this regard.

    4. My first TDA1541A DACs were using 2.2 uF at two most significant bits, however the gains were not that important, especially taking into account inevitable compromises regarding the caps quality. On the other side, Philips papers recommended completely abandoning DEM caps, if synchronous DEM clocking is used. I did not find it however sounding good, either. So, a 100 nF is where I am at, for many years now.

    5. I did not find any use of it, either technically or subjectively speaking.

    6. Simple circuit driving only one pin appears to perform the same. The jitter is not critical here.


  28. 17-10-2018

    Dear Pedja

    are there any boards still available ?

    best regards

  29. 18-10-2018

    Pepe, at this moment there is a couple of spare boards with pre-fitted USB stage, and one more board that will be fully populated.

    Also, one information regarding the shipping. All the modules will be shipped until Monday. Then we will start shipping completed devices, and hopefully send them all during the next week.

    Thanks everyone for patience.


  30. 18-10-2018

    Thank you very much for your response Pedja, I have just sent you a message via your contact form asking for pricing on the boards. You will see there my email to answer.

    best regards

  31. 20-10-2018

    Reply sent.


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