Which purchase tipped you into nirvana.

Emm Labs CDSD/Emm Labs DAC 6. Boosted my redbook collection with a unveliebable digital sound.

....buying a used pair of Dunlavy SC3's and upgrading from an integrated amp to seperate amp/pre-amp. I can't tell you how good those speakers sound: the clarity, depth, and articulation never cease to amaze me. I bought those speakers 12 years ago and someone will have to tear them from me. Unless, of course, I run across a used pair of SC4a's. (just kidding)

Maestro ac outlets! Made my entry level system sound damn GOOD! I did the review on these outlets too soon because these outlets are still improving every day... more open and more spacious sound as they settle-in more! Look at my review

Lyra Delos, 1. Series

After 30 years in this hobby, I have found one piece that I think qualifies in answer to your question: the Berkeley Audio Design Alpha DAC. When I found this, I was about to despair over Redbook CD reproduction. Now I think I may be close to the end of my search for a truly musical sounding system.