My current incarnation of my 2 channel stereo rig.  And quite possibly my best yet in terms of sonic quality but also frequency response, time alignment, and more importantly flexibility to control each speaker/sub individually for crossover (frequencies and slopes), delay, volume all via DSP and FIR correction filters.  But it's taken a long time to learn, measure, learn more, measure again and finally go with a multi-channel DAC that was the key ingredient to allow such flexibility and control.  But having the puzzle pieces doesn't mean that they go together easily so more learning and finally bought another key piece which was the Audiolense XO software to create a FIR correction filter for frequency and time alignement.  The multi-channel DAC and FIR filter capabilities were BIG TIME upgrades worth more than any amp or preamp!

Happy listening to you . . .