Next I am planing to use this guide to calibrate the SMEG+ into feeding low-level audio output to the speaker wires. The line-out output should make connecting an external amplifier (which I am doing) much easier and much less noisy and distorted. It is allegedly possible to calibrate this, but I couldn't find any evidence/mention online of someone actually doing it. Maybe someone here had tried it, or knows if it is actually possible?
The easiest way is via diagbox.
I don't know, which setting for the amplifier is correct because they're more than just 2 settings.
My calibration is with an external amplifier, so it might work for you.
Check out the line "Audio_export_conf" in the first post im the picture.
and further specifying that only 2 instead of 4 outputs shall be provided in the HIFI CAN mode, and that they apper at the front speaker terminals:
That's right, it's rhe same like the Nac.
Only two Low Level Channels are active, when the amplifier setting is set to external.
But note that these 2 channels deliver a constant low level volume, they are not adjustable!
The volume and balance are regulated via canbus.
The original amplifier from psa split the 2 channels in 4 channel + subwoofer channel.
If anyone had done this before, I'd very much like to hear about your experiences! If not, I shall try it in a couple of weeks and report back with the results
Only with nac and diagbox, but it's the same way with the smeg.
If i had written down the can frames, it would be easily possible with Arduino and an mcp2515.
But at that time i wasn't familiar with the the can network.
Now my smeg is sold long time ago. 
