I think the best way to upgrade our audio is to upgrade the whole system, not jut one component. I guess it is almost impossible to notice big differences in sound just upgrading a speaker, a preamp, amp, DAC, etc. because there will be a big mismatch of components.
Another important factor is to have a sample of what you want your system to sound like. A $10K system will never sound like a $30K system, nor a $30K would never sound like a $50K system and so forth. About 2 weeks ago I auditioned 2 different setups; one was about $50K and the other one was about $100K. All components were matched to their qualities in price and there was not weak link in the whole system. What I listened to was a very impressive and amazing sound.
All audio components work their best in concert with the rest of the system that are made about the same quality and price.
Don't expect to get a night and day differences of a $15K speaker cable out of a $200 CD player. You need a $15K turntable and a 180 gm brand new LP as a player device, $30K speakers, a $13K Preamp, $22K mono amps, $5K interconnects, etc. Just then, you will notice a real difference.

