Biggest impact on you?

Curious: I’ve gone through a lot of gear over the years. In reflecting upon this, a Conrad Johnson MV-45A1 power amplifier I bought back in 1983 had the biggest impact on me. This includes consideration of the many preamps, speakers, cables, CD players, and so on that I’ve owned through the years.

Has that piece been the best I’ve ever had or heard? Absolutely not. But, it was the first high end piece I’ve owned and it wowed me big time. Ran it with Vandersteens, CJ’s PV4 preamp, and a Sonograph TT – loved it!

So, what component (power, pre, speaker, TT, CD, etc.) has had the biggest impact on you?
The first was my first stereo in (dare I say it) the mid to late 60's. AR4X speakers, a Fisher Rec, and a Dual TT.

Second years later, after dozens of changes, was an AES AE3 tubed pre. Wow, I could now really hear the wood in the guitars.

Third was Analysis Plus Silver Oval IC's.

Forth and most recent, a year or so ago I replaced my Cardas Cross Speaker cables with Paul Speltz's Anti Cables. Wow and considerably cheaper too.
Goldmund studio Table with 3B arm just a fabulous table and a shame it's not in production and bettered.
Modwright SWL 9.0

First piece of tube gear and man what a difference it made. My first Sansui AU-7900/TU-7900 combo back in 79 was big as well.
Phase Linear 400
Stage opened and images became more dimensional
MIT 330
Finally heard bass notes from my Quad ESL 63
Tron Syren Full Function Pre.
To my ears it just seems to do everything correctly
Far and away the very best component I have heard and now own