I must say I found the RED fuse more of an improvement then the Cardas Caps. Not that the Caps did not help.
We all have different systems and environments but not in my system. Most obvious improvements are any glare are eliminated, smoother mid/high and easier to decipher lyrics in complex passages.
One example is Mary Chopin Carpenter, Time Sex Love. Heard it on many EXPENSIVE system. It's a horrible recording, harsh and glaring. After installing the caps, glare was gone and no harshness. I guess it was cause by noise?
I bought caps for every component, amp, pre and dac. Cardas RCA non shorting pin, Cardas XLR output caps and AQ XLR input caps with no shorting pin. I use copper sheet to cover connectors that don't have caps. ie USB, I2S ...