I actually just sold one. Modified Sonos Connect. I2s over HDMI. Modification was performed by Wyred4Sound Audio in Atascadero, CA. The Sonos works as an endpoint, but its not RAAT ready. You might be able to modify a RPI to work.
See the RoPieee thread HERE as someone (Artur) (and I will be trying soon too) has an i2s DAC board thats connected to a RPi i2s - but of course this is all internal as the RPi has no connectors for i2s - you would have to figure that one out…maybe too much DIY for many.
Singxer SU-1 is an excellent digital interface with i2s output, especially when modified to be used with an external linear power supply such Uptone Ultracap LPS-1.
However, it is not a network player, Roon endpoint, and you would need something like microrendu to provide that function.
This is the combo I have:
Roon —> Ethernet to microRendu —> USB cable to Singxer SU-1 (powered by LPS-1) ----> i2s ----> Holo Spring KTE DAC
No, since the language that DACs speak is I2S (I’m told) I’m considering that input myself - if I can find hardware to consider and keep the chain length down.
Hence as per my OP, ethernet to I2S - and no USB and SPDIF along the way.
As Joel says, $5k for the Musica Prestina is a lot to bypass USB, even though I’m sure that is a phenomenal bit of hardware.
Hopefully some other options come up also.
And before someone else jumps in, yes I know the Bridge II is ethernet to I2S and Roon Ready !
There are several different pinouts being used with the HDMI connectors for DAC’s. PS audio is one approach, there is another which I can’t remember, maybe it’s Holo Spring or perhaps some other brand. Denafrips has a dac with 3 i2s inputs, one is on HDMI and 2 on RJ45 I think.
I’d like to point out the HDMI that keeps cropping up in all the i2s banter is the physical connector that’s being used, nothing to with the HDMI signaling specs.
It’s akin to having an rs232 connection on an HDMI connector, the signals are very different but the physical connector is the HDMI type.
The only thing I’d add is, if you’re going to these lengths to avoid USB, you probably need a really low jitter I2S output. The I2S input on the Holo Spring, at least, is not re-clocked. The reason people go for the SU-1 is that it’s I2S is very low jitter.