The first predecessor of AYA DACs was released as a DIY project via Pedja Rogic DIY site, back in 2003. The project documentation was relatively extensive, including complete circuit description, with advanced zero feedback I/V stage based on the integrated circuit AD844, and layout principles were explained too.
The second incarnation of this project (rev 1.1b, from 2004) was supported by the PCB offered to the DIYers.
Success of this project exceeded all the expectations, and it was followed by another one in 2006 (rev 2.0b), which was named the AYA DAC. This DAC had several changes regarding the layout around TDA1541A, and supplies used.
The AYA II (2007) came not only as a DIY project but also as a completed device, and the whole enterprise was then taken over by Audial brand. The AYA II abandoned asynchronous reclocking but brought improved S/PDIF input stage, and new output stage, now based on the Burr-Brown OPA861 transimpedance amplifier (“super-transistorâ€), instead of previously used AD844.
The AYA III (2009) came as an S/PDIF only version of AYA II.
Several output stages, all zero feedback, as well as several other articles associated to these converters, and a bunch of measurements, were published during all these years.
These DACs and projects didn’t only open new understanding of the DAC performance, and didn’t only increase the DAC standards, they’ve also changed the way the people understand the DIY scene in this domain, and changed the DIY scene itself.
The AYA II and AYA III DACs are the crowns of this development. Highly optimized in all the aspects, they are the benchmark regarding moderately priced DACs, and we are convinced that they will remain like that for quite some time.
It is still not decided when and which way the AYA DACs may be possibly replaced, but it is sure that the successors won’t be the TDA1541A based.
As for Audial and TDA1541A chip, once the AYA DACs are discontinued, the Model S will remain the only Audial DAC with TDA1541A chip.