Get either the Rotel RA-1592 stereo integrated amp with built-in DAC. It retails for $2500 new. It is a great and musical sounding integrated amp and has more than enough power to drive your Polk RTi A7. Has good sounding DAC too.
Or if you want to get stereo separates I recommend the Rotel RC-1590 stereo preamp with built-in DAC with the Rotel RB-1582 Mk2 stereo power amp.
The RA-1592 integrated is actually the RC-1590 preamp/DAC + RB-1582 Mk power amp put together in a single chassis. The sound is full warm with smooth highs and very refined sounding amps and will be a good match for your Polk RTi A7, which are lean bright and somewhat harsh sounding speakers.
Or if you want to get stereo separates I recommend the Rotel RC-1590 stereo preamp with built-in DAC with the Rotel RB-1582 Mk2 stereo power amp.
The RA-1592 integrated is actually the RC-1590 preamp/DAC + RB-1582 Mk power amp put together in a single chassis. The sound is full warm with smooth highs and very refined sounding amps and will be a good match for your Polk RTi A7, which are lean bright and somewhat harsh sounding speakers.