Okay, FYI : So I'm an official member of the"a 'fellowship of the Susvarians" since this morning. My unit (the Susvara) landed today, and so far I am listening to it on this system :
Sonore Optical module (optone audio LPS 1.5) ==>> Uptone Etherregen (Paul Hynes SR4T LPS) ==>> Metrum Ac Ambre (I2S) ==>> Sonnet D.Morpheus ==>> Flux Lab FA-10 ==>> Susvara
Welcome to the club. Your chain is very close to mine (Ambre > Morpheus > Class A amp) and I am sure that the sound is exceptional. But for others who may be putting together a similar chain from scratch, from a system budgeting perspective I am curious about the sonic benefit of the optical module and etherRegen and a couple of expensive LPS's. Everything up to the Metrum is asynchronous data in packet form and the Ambre comes with optical isolation at its ethernet input. The pi is further galvanically isolated from the signal processing and timing sections. The two clocks in the Ambre are very good. I2S is the optimum connection to the Morpheus. If you are streaming from the internet, the packets have already made their way through a high number of copper and optical switches. I have some difficulty understanding how the last one can become sonically important. I did a test at my home by replacing the wired ethernet with an optical link straight from my HP managed switch (which has optical ports) to a media converter at the Ambre. It is the same switch that my Synology NAS is connected to via a 4-ethernet trunk. So for FLAC files on the NAS this is about as direct and isolated as one could get. Maybe it is my tin ears, but I could hear no difference. We agree on the Metrum, Morpheus, and Susvara (which is the heart of the matter) but I would suggest that someone building this chain from scratch spend the remainder of the system budget on the highest quality and most system-synergistic class A power amplifier that they can get. I am just another anonymous opinion on the internet, but my ears can't hear ethernet and the stock Hifiman cables on the Susvara, though they have a cheap rubbery feel, are good bi-metal silver/copper cables and sound fine.