ADC / DAC add-on for DIYINHK Xmos USB to I2S PCB

[elskardio]

Hi Guys,

I just finished a project where the client needed a high quality USB interface buit-in.

After testing a lot of options, I ended up with the Xmos PCB made by DIYINHK.

I built a small PCB with a PCM1802 ADC + a PCM5102A DAC. There's also input & output buffering + filtering.

Everything is powered from a single 5V DC.

The results are pretty good. Next step would be to program my own Xcore processor... but that's a lot of work for someone with no coding skills

Cheers

 

[Tubetec]

I looked at a lot of the Xmos boards and the DIYINHK I/O boards were the only ones I could find pre configured for input . The prospect of programing the core is exciting but again in terms of the coding its a big learning curve for me also .

Whats the functionality/ stability of the syscon drivers like in the daw, did you buy the full version driver ?

Frequency responce at 48 khz looks great , 96khz drops a away a bit , did you make a compromise in the filtering on the inputs to suit 48khz better?
Its probably fair to assume from the specs of the opamps they dont contribute anything signifigant in the way of THD or noise .

Congratulations on creating a really cost effective USB audio interface , will you make the board available at some point ?

Sorry for all the questions ,

 

[elskardio]

I did a bit of tweaking to the filters to improve the frequency response at 96kHz.

Just for fun I did a comparison at 96kHz with my Motu M4 (really nice unit by the way)

I can't comment on the Windows Driver since everything I do is on Mac OS. Built-in Mac OS driver is rock solid.

 

[Tubetec]

Very impressive result.

Did you happen to order the xmos programming module along with your board ?

Thesyscon provide a few different programming tools with a graphical user interface .

 

[mhelin]

There is no need to re-program that Xmos chip. Anyway, you have to solder in the xsys header and use the xtag programmer to do it, but it looks like there is no space reserved for it on the analog board. You also need special config file (XN file) for programming your board, for the compiler, it defines the pin mappings, chip model, flash and so on, I don't think diyinhk provides that.

 

[elskardio]

No need to flash the firmware at all... but you’re stuck with Diyinhk usb product ID. My client’s project was an in-house product for their own use, so he didn’t mind if “Diyinhk Usb Audio 2.0” was showing up as his device name... but for a bigger project it wouldn’t be professional.
Diyinhk won’t share any files... but they can flash a custom firmware with your own product ID if you order 100+ of their PCB.

 

[mhelin]

Didn't know they have such a business.

Here's a good writeup on subject (of using the Xmos processors on actual work):
https://laforge.gnumonks.org/blog/20170902-xmos/