Interesting Setup - At least in my eyes

So, on a Sugden Group on FB, a user had posted a question about using his A21a Series 2 Integrated Amp as an amp (he was inquiring if the pre-amp section was active or passive).

But my initial thought was, how is he using it just as an amp, it's an integrated with pre-amp outputs and so he could use it as a pre-amp if he chose to but how could he achieve turning it into just an amp, didn't make sense to me.

So I inquired and apparently he is utilizing a Moon 390 Pre-Amp (using the output from the 390 to one of the inputs on the Sugden). He stated this basically allows him to have 2 pre-amps in the chain (his words).

I looked at the rear of a 390 and it has a fixed and variable output (he didn't specifiy which one he is using). He did state this allows him hdmi switching and 1 volume control.

So basically, in a way he is getting additional inputs with the hdmi, so that part finally made sense to me.

I thought that was interesting. I never hooked up components in such a way but I guess it;s possible.