Biggest Sonic Improvement

Living in a condo, with horrible power, I've found a Chang Lightspeed 9600 ISO was a HUGE upgrade for a little investment. The noise was completely gone, bass was tighter and more abundant, soundstage opened up, hell I love it so much I bought a 9900 amp for the high draw components in my home theater! (I'm still waiting to get a Ps audio for the low draw- I just can't see the ~$4000 they say I'd need for my system at this time) NOTE: "at this time"! I do love this hobby!

Black Diamond - those things under speaker spikes. Yes, you can't believe teh difference. I am surprised there isn't more out there on this tweak.

I had to hear for myself what SACD sounds like, so I drove an hour to a dealer. It took less than 5 minutes to realize that SACD represents the biggest sonic improvement I've ever heard from a single change or am ever likely to hear--short of virtual reality. Over time, as the quality of SACD mastering improves, just as it did with 16/44.1 standard, we can expect wonders to be everyday occurances. Many early adopters describe their good fortune on audioreview.com. In my own system, it would have to be going from stock cords to custom powercords--proving that cords are components too.

High-end tubes from high-end solid-state. Absolutely! Tubes aren't perfect, but their benefits outweight their minor drawbacks.

When I changed a Conrad-Johnson DR-1 to my Mark Levinson No. 37 I noticed a steep difference.