Can someone tell me what's going on?

I used to run a pair of Audio Magic Clairvoyant Ql (xlr) ic between my Bat vk5i preamp and Bat vkd5 cdp and Nordost Quattro FIl (rca with xlr adapters) between the Bat preamp and Bel Canto amp. The sound was so so in terms of effects of the ic, nothing loss, nothing gain. When I switched the Quattro Fil to cdp and pre and Audio Magic to Pre and amp, everything changed. Bass becomes deeper and tighter, soundstage extended way beyond the side and rear walls, instruments are clearly separated with more body, and a greater sense of dynamic and mysicality is present. Unfortunately, I only have two cables and I'm still relatively new with all this stuff. I have heard mixed comments on where the greatest effect of the ic makes. My local dealer has told me between amp and pre, but I've also heard it's between source and pre. I'm thinking of replacing one of the two cables, because I want more of what I've heard. Can someone with more experience diagnose what happened. My thanks in advance.