Best tweaks so far....
1) Computer audio design......www.computeraudiodesign.com. Went with the GC1 and have one post connected to my dac and the other to my streamer. Takes out any unwanted high frequency noise, etc. I didn't know I needed this until I hooked up the demo unit for a week then took it out of the system and WOW what an amazing tweak I didn't know I needed....ha ha.
2) bought Audiuoquest lifters too get all my speaker cables off the floor and separated from touching any other cables and cords.
Those are two of my best tweaks.