Best Stereo Upgrade Value

A question for you audiophiles...

What "upgrade/change" has singularly given you the biggest (not incremental) improvement to your stereo system?  Upgraded amp, pre-amp, tubes, room correction unit, subs, connectors, cables, speakers, streamer, stylus, speaker placement, acoustic panels, etc.?


Every time I have done a component upgrade the sound improves.  It also costs a lot more money with diminishing returns.  So pick you weakest link and have fun.

By far for me new amps.   Upgrading from what I thought was an awesome and venerable Classe stereo amp (CA 2300)_ to Audionet Max monoblocks was eye and ear opening!

A good point. The way you hear is critical.

Much like vision. Do you see the forest, the trees or the leaves?

Are you seeing the details, or missing the finer points?

Are you hearing the details, or missing the finer points?

I'm sure some will agree while others will be bemused.

It's like those who declare digital is 0/s and 1's. Totally superficial and oblivious of the details.

The single biggest improvement in my system was moving to planar magnetic speakers (Apogee Duetta IIs, and when those died, Magnepan 1.7i).