WOW factor


Just wondering what upgrades or changes to the system made big differences in sound in your system?
For me there were a number of things, but I'll start with: suspending my speakers from the ceiling using cables attached to rubber mats coupled to top and bottom of speakers held in place with cables. Prior to that I had plywood squares coupled to speaker's top and bottom surface which produced alot of bass resonance. The rubber mats made the sound dark and quiet. Also floor does not resonate. This is one of many things I discovered.
pedrillo
3-inch-thick maple platforms for my monoblocks. I really wasn't expecting much, and the difference, especially in the bass, was WOW.

Things others have mentioned (NOS tubes, new preamp) have certainly been surprising too, but this one did a lot for not too many dollars.
I would like to contribute another: lead shot through out my turntable made big strides.
There was a time when I wanted to put lead shot through my turntable, but then found the problem was only the left channel on the cartridge wired out of phase.