USB audio codec with SPDIF or I2S out

..actually, the PCM2902/6 works also at 96 kHz, also up to 100 kHz. But its bandwidth is limited to 24 kHz. Here are some loopback tests done on a soundcard that I designed, based on the PCM2902/6.
(PCM2902 and PCM2906 are basically the same chip)

The bandwidth is obtained from the FFT of the loopback impulse response.

Loopback at 48 kHz:
[IMGDEAD]http://img297.echo.cx/img297/1301/x4loopback487dg.th.jpg[/IMGDEAD]
(click to enlarge)


Loopback at 96 kHz:
[IMGDEAD]http://img297.echo.cx/img297/6265/x4loopback965xl.th.jpg[/IMGDEAD]
(click to enlarge)

The bandwitdth limit is visible and measurable :bawling:


I checked the SPDIF output of the PCM2906 at 96 kHz, full of hopes.. but it is limited to 48 kHz:

[IMGDEAD]http://img297.echo.cx/img297/9646/x4spdif965xn.th.jpg[/IMGDEAD]
(click to enlarge)

The SPDIF out from the PCM2906 has been analized using the digital input of another soundcard (by RME) that allows to analyze the incoming digital data
 
Get a separates, build a board, write a driver and that's it

Yes, I know using a generic USB device controller and writing some lines of code can support anything I'm looking for. Unfortunately it takes some month of work...

I just took a look to the Cypress CY7C6801x series. Seems to be possible when using an additional FPGA.

checked the SPDIF output of the PCM2906 at 96 kHz, full of hopes.. but it is limited to 48 kHz:

Interesting that it works at least. Maybe the driver itselves limits the datarate to 48kHz?