Mine was going from the Harmonic Tech Pro AC 11 on my Wadia 860x to a Powersnakes King Cobra.
Biggest Sonic Improvement
What is the biggest sonic improvement you have ever made to your audio system. Mine was a surprise to me. I replaced my Audioquest PT6 tonearm on my VPI turntable with a VPI JMW Memorial tonearm. The improvement in the sound nearly knocked me off my feet. I never realized a tonearm coud make that much difference in sound. How about some of you guys, what has your most exciting improvement been.