@arvincastro I’ll add, looking at your system, depending on how much you are willing to spend on the next upgrade, your weak links are:
1. Preamp - the LS7 was a pretty good preamp back in its day. However current Audio Research line of preamps is amazing. They’re quiet, dynamic and transparent. Picking up LS28 will help you get the best out if your new DAC
2. Amps - pair the new preamp with a more modern amp, solid state or tube.
3. streamer - you can get away with your current one but use USB into Chord DAC. Let the Chord clock do most of the work. Eventually pick up a good streamer like Innuous or Aurender
I owned ARC LS-15, LS-16, LS-25, Ref1 and had on loan the latest Ref6. The Ref6 is dead quiet for a tubed pre and sounds incredible. You want smooth and big sound with those Kefs.
Just some thoughts…