Hi Fret, thanks for your valuable input on the Allo products. The USBridge Sig is definitely an interesting product to think about. And I do...
I will follow, what you will find out about it.
Regarding the P4 versus 3B+. I'm not sure if higher processing power can be translated into a gain of musicality of the system. Noise is possibly increased too, due to the increased processing power and higher power consumption. This is a topic where some information can be found on the net. One article I found highly informative is this one:
https://www.mojo-audio.com/blog/compute ... nceptions/
I was close getting a Pi4 but then decided to stay with the 3B+ - despite the weakness of the 3B+ with its shared USB / ethernet bus - due to all the information I gathered on the net about what possibly makes a good computer audio device.
So, I have invested - as the above paper suggests - also some thought in the power supply for my SBC DAC solution. I now have - just mounted on a piece of wood - three regulated ps, one for the pi, one for the Ian FifoPi and one for the ESS-DAC plus one extra regulator board, which powers the 3 voltage rails of the DAC with 3.3v each. The ps together with the PI/DAC stack look a bit like a christmas tree as quite a few leds are glowing in different colors, when everything is on
- but it seems to help the sound, too. Especially, the extra regulator board for the 3 voltage rails of the ESS9028 DAC made a difference to my ears. There is more flow in the music and the sound stage opens up quite significantly.
There is a lot more to try according to the paper. So let's see, when there is time. It is definitely fun and a lot to learn.
In my opinion, it is quite a task to get great musical experience from an SBC based audio device and some DIY. I can fully understand Stu, his KISS principle and his preference for a well made / upgraded CD player.
I still come to the same conclusion and am not at all disappointed...
Good luck on your further efforts to reach audio bliss!