High Fidelity Cables MC-0.5 Effect

Mad Scientist Nitro Nano is much better than Nitro

Have contacted Bob.
Will replace the Nitro with the Nitro Nano, after I pay for some Black Ravioli pads.

I auditioned the MC-0.5's. I used two modules in my system and the effect they had on my music was astounding. They're not power conditioners, although they do lower the noise floor, but they create a holographic image. It's so hard to explain in words, but the music image is very clean with instruments sounding more realistic in terms of tonal quality, attack and decay, and a more defined sense of the recording space. It's more than what we call soundstage, it takes you closer to being there.

It was very addictive. Unfortunately for me, they ultimately didn't work out in my listening room. My system is neutral with smooth extended highs. Over time, the modules created such top-end extension that my digital setup became very fatiguing to me.
After removing them, I missed the holographic sound they had created, but I preferred my analogue-like digital system.

I use a HF CT-2 digital cable with streaming and CD playback to an Audio Note DAC.
I suppose I could have made some tweaks such as tube rolling to retune my system. 

I still will recommend them, YMMV.