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?