I was wondering if a HifiBerry budle would be possible:
ADC(2 analog inputs) -> DSP -> DAC->AMP
It seems that board almost does it (minus the DSP) :
https://www.hifiberry.com/shop/boards/hifiberry-aamp60/
Since it can be plugged to the DAC+ ADC Pro.
Basically the bundle would be the "heart" of a specialized instrument amplifier.
Adding a DSP to the "aamp60 + DAC+ ADCPro" would simplify the speaker design, as well as offer interesting possibilities.
The possibility of adding an ADC to a BEOCREATE would also be great.