Poll: Most impactful component

For varying reasons,  I toggle back and forth between a PrimaLuna integrated and Pass amp/Cary preamp combo.  I also recently upgraded from a NODE/Qutest (w/ SBoosters) combo to an Innuos Mini/PSAudio combo.  Zu speakers are the constant.  Nordost cables.  Stream exclusively.   No question that the Pass/Cary/Innuos/PSA combo delivers the best listening experience to my ears.  That's not answering your question other than to suggest the obvious that it all matters.  If I had to pick, though, I think the streamer upgrade made the biggest difference in my modest system.

which component has the most potential to improve a stereo system?

I think it depends on system deficiencies.

I have B&W 804`s teamed up with an Acurus A-150 power amp. (a BIG no-no!).

 In order to rectify the harshness in the upper frequincies, I inserted a tubed preamp into the system. I `ve taken a sows ear and made it into a silk purse.

Generally speaking I think it`s the preamp, and/or a DAC.

1. Room

2. Speaker position

3. Everything else

To me it’s speakers ( EPIC CF4 VI) way better than any speakers ever in my room it’s not about the price but the dynamics clarity and bass response room will be second and Preamp Third