No, the issue with the Pi4 has to do with how the stream is handled between the Pi and the Iancanada FifoPi. I haven’t been able to test this out with other cards, since there’s only a few cards that actually take the GPIO output and translates it to i2s in LVDS. For example, the Pi2AES is capable, but the current iteration is not in the PS format (switched L/R), which is easy enough to compensate for, and they are supposedly fixing that in a new version coming out early this year. But @ $200+, I might as well buy a Pink Faun for my PC. Plus I’ve been able to fix that with the JRiver setting as noted above anyway.
Also note that I haven’t tried it, but you should be able to just run the HDMI Transmitter without the FifoPi since the DS does not really need the MCLK signal, so I haven’t tried it without the FifoPi to see if the behavior is the same. I got the FifoPi in case I decided to use it with the TransportPi to output S/PDIF via coax or toslink to another DAC in the future because the FifoPi allows you to swap clocks. Right now, I have the CCHD957 clocks in there.
I posted a couple of pics of the setup here:
The value of high $$$ clocks may be questionable for the DS, however, since as long as the jitter is decent, the DS has to reclock everything anyway as part of the conversion to DSD.