Bel canto monoblocks and power cables


For those, like me, who believe power cables make a difference: anyone with experience with bel canto amps and power cables. I use Nordost Vishnu with all of my source equipment and hear significant improvement.  With my BC ref 500m monoblocks, which I love and which sound so good, power cable swaps don’t seem to make a difference.   I’ve tried Nordost and Acoustic Zen Tsunamis. They don’t degrade the sound but there doesn’t seem to be much benefit either.  Anyone?
tomaswv
I have also found that with a really good audiophile quality amp I don't hear a noticeable difference or perhaps just a tad of difference when trying different high-quality power cords. In this particular case, I'm talking about my Plinius SA Reference amp.  I do hear a significant difference with my preamp, phono preamp, transport, Dac, and FM tuner.
We need someone like @almarg to explain this.
I've been experimenting with power cords and interconnect cables lately. Several manufacturers told me the most impact will "usually " be found by upgrading the power cords at the source and using the best interconnect at the source. 
I have ref1000m amps. These draw a lot of current when powered up not so much after. I use basic cords on those. Higher grade shielded cords on source gear. The amps power supply seems designed well to have power in reserve when needed. So I have not felt a need for beefier power cords. The amps are very efficient sound great and never break a sweat. Beefier cords not needed as much in some cases compared to others. Devil is always in the details.
i have 3 ref 1000m amps across my front in a HT configuration. I have used Crystal Cable, Siltech and now Purist Audio Designs (Neptune). I can def attest to a change in the tonality as i moved across the power cords.

it may be that the power cords you have chosen actually sound similar and therefore you didnt hear much difference. 
@thomaswv - Like you, I found good PC’s on my NAIM amp did not make an immediate noticeable difference - I had to find the right track that made the improvements more noticeable.

Those improvements are the micro details of the venue acoustics - now I know what improvement power cables make it is easy to hear and noticeable when you change back to a cable of a lessor ability.

I use the following DIY cables that I have compared to a few high priced products and found the others lacked the bass dynamics (slam) and very fine details of these
http://image99.net/blog/files/be8de0c383c5434907610d6b55049e69-75.html

Check them out - despite their apparent complexity, they are pretty easy to build

Regards - Steve