Okto Research DAC8 Stereo - Streamer

[Qwin]

This looks fascinating as a Roon Endpoint.
Colour me interested!

Any way Ken a PS Audio comparable i2s output can be introduced to the mix?

No sorry it can't. At least not without some major surgery.
The GPIO socket on the internal Pi is only used for supplying power to the Pi.
Pavel (designer and CEO) at Okto used the asynchronous USB output of the Pi4 for audio.
I asked him and he said it is a very clean signal with no timing issues, on the other hand, the i2s output of the Pi4 is not good and needs re-clocking, it was much more straight forward to use the USB output to achieve good results. The results are spectacular, best measured to date at ASR forum and the subjective sound quality is equally as pleasing.

Note, I found on my PS Audio Stellar GCD that the i2s signal from my CD Transport did not sound as good as its coax SPDIF or AES output. I even bought a fancy (expensive) 300mm long HDMI lead, praised for its audio quality, to try and address this, but it made no difference.

It seems to come down to the quality of the implementation of i2s as to how good the results are. In the case of the Pi, its not done well, Allo do a re-clocking board for the Pi, the Kali, to address this issue, it costs more than than a RPi4B does, think I paid about £70 for one a couple of years back.
Sorry Gaz