First I have no experience with your current equipment, but you have gotten some good recommendations. If you have $4,000, here is a good start:
Schitt Freya+ preamp - $850
Denafrips Ares 15th DAC - $1,150 (or better yet a used Denafrips Pontus II $1,400)
Used BlueSound Node 130 (not 2 or 2i) $375 (or better yet used Innuous streamer $1,400)
Decent cables - Zavfino makes great affordable entry level cables, Arcadia interconnects, Nova speaker cables. Supra cables makes very good entry level data cables; Excalibur USB cable $110, Cat8 ethernet cable $50 2 meters.
All of that would be around your $4,000 budget, and each component could easily be upgraded as you can afford later.....but this would be a very musical starter system that you'd love to listen to