I’m gob smacked. What were you’re aha moments?

biggest surprises/improvements regardless of budget?

Many contenders!

1. Black Diamond Racing Cones. Still the best. Thank you, DJ. RIP.

2. Hexfred diodes

3. Synergistic Research- pretty much everything. First shock was replacing $2k AudioQuest Dragon speaker cable with I forget what SR but the shocker was they were only about $300!

3. SR Active Shielding. Jaw-dropping demo.

4. Cryo. Found a local cryo tank, tested a few things, and when I heard how good it worked pulled everything from the panel to the speakers- yes everything, house wiring, entire CD player, EVERYTHING and had it all cryo'd. (Not ripoff audiophile pricing either. Cryo One. Total bargain.)

5. Anti-static and Demagnetizing. First was the demagnetizing tracks on the XLO Test CD. Then the Radio Shack bulk tape eraser on CD's. Then on records, cables. Then Cable Elevators lifting cables up off the floor. Then plain old laundry anti-static spray. Do it all some night. You will be gobsmacked too!

6. RFI. Thought this was BS. Then one day discovered its not. Flip off all the other breakers late at night some time and have a listen.

7. PHT, ECT, HFT. Absolutely gobsmacked! 

8. White Hot Stamper. Records do not all sound the same. A precious few are so close to perfect you simply cannot believe it. Until you hear it. 

The first time I visited a high end audio store and heard what music reproduction was capable of as opposed to my dad's cheapo system at home,lol!I don't recall the brands on display.
The first time I listened to a Conrad Johnson tube amp transform the music when swapped in for a ss amp.

Aloia power amp. This amp with its the separate induction power supply is absolutely wonderful. 

My very latest addition of SET mono’s from Audio Space Reference 3 (805). What a bargain, they were a blind buy and I didn’t expect them to be so crazy good! 

I swapped out the chinese stock tubes with some NOS and Sophia’s 300B tubes....wow!!!