Which component(s) made the biggest difference when replacing older ones?

[Feanor]

Most of us here have had numerous different amps, speakers, turntables, etc., all purchased in that pursuit of the elusive "perfect" combination to produce better and better sound. Some of my purchases over the years provided little or no differences, but others were all but staggering.

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Avoiding the old "which is the most critical component?" debate, I must say I had a moment of revelation when I compared a pair of Monarchy SM-70 Pro amps with the NAD C270 I was using. It was a learning experience because I had not expected to hear such an improvement resolution & transparency from any amplifier versus the ones I had previously used.

emaidel, sounds like your Adcom to SA8001 experience might have been like that. For my part, as yet I have not hear such improvements from any other compenent upgrades except speakers, but I'm up for the experience.

In the old days when I gave a poop about vinyl, I could get pretty big differences swapping phono cartridges, but of course I expected to hear significant changes in this case as with speakers.