The impossibility of sound quality difference whatever the medium

[f1eng]

Nice to see the Devialet Expert experts in a Phantom thread!

I have and enjoy both
Expert since 2011, Phantoms since March

[streamy]

I have and enjoy both
Expert since 2011, Phantoms since March

I know from your postings and I enjoy and appreciate your engineer point of view. Precise and facts based, even or specifically when human factor is in play!

[iliapas]

Just a few cents here about the possible differences:
Wifi streaming will send data to Phantom, which then decodes the file and sends the raw audio signal through the connection between the Application processor (some ARMv7 core) and DSP, with hopefully minimal interference or clock issues between then. So here the error you get from connection between ARM CPU and the DSP.

Optical signal arrives raw, and toslink is known to have some minor clock/sync issues because it's a one-way connection (receiver has no way to interact with the source), so the signal might arrive clocked slightly wrong, and quality using optical connection will depend on: CPU->Optical board connection, optical transmitter quality on the source, optical cable (minor effect), optical receiver n Phantom, optical receiver->DSP connection on Phantom.

Now, with current technology, none of the above look like major sources of noise, so hopefully you get pristine sound from both connections. But if you're pedantic, in theory the buffered Wifi connection has less possible error sources (well, only the ARM->DSP path) than optical (CPU->Tx,Tx->Rx,Rx->DSP).