Silver cables added resolution

If you feel the mains is the source of your noise, you may want to try a good mains filter. 

I use pure silver cables (no copper) all the way through and do not exhibit the noise you speak of. That said every component goes through a mains filter AND an isolation transformer. Each component has it's own isolation transformer. 

My cables (IC and speaker) are also active - they have a 9v positive bias on the shield that is shunted to ground. 

@Fil, did you alter your gain stages at all when you switched cables?  If you turned down the output in your source device (and any other stages along the way), which meant you had to turn up the volume at your pre-amp in order to get the same amount of sound out of your speakers.  By doing this, you are also turning up the noise throughout the system.
If you keep your source levels high, as well as any adjustments along the way, then at the last point--the pre-amp--the volume does not need to be adjusted high for the same volume.  This means that the noise in the system (all systems have some amount of noise) is not boosted higher either.
If all of the gain stages before the final pre-amp one are set so high that you can barely turn up the pre-amp volume without blasting your speakers, then you'll need to find some balance by turning down the earlier gain stages.  You want to find a sweet spot where none of the gain stages are so extreme it makes other gain stages set at unworkable levels.

Sorry, if this doesn't make a lot of sense. I come from a pro sound reinforcement background where we typically deal with a lot of gain stages before the sound comes out of the speakers.  I'm trying to describe it in more layman's terms, instead of the lingo me an my work buddies would use.

Silver huh. Great. 

Try using DeoxIT gold on your connections. Even on new cables the connections can be dirty. A small bottle is about $8.00 on Amazon. A ground loop can also cause hiss, maybe it was always there and the new cables are revealing it now. iFi makes a nice little product that eliminates the ground loop hiss.

Hi all,

l am now waiting for new Power cable to arrive, if all go as expected, I should see a drop in the hiss has This new cables are shilded and the current one are not.

I Will keep you updated.

Has for @johnnyotto points.Thanks for your input, I did not change the Gains, Amps and pre amp are playing ok.

In the building where I live, there are some mobile antenas, and I think the issue is cause by:
- missing shilded power cables
- mains noise generated by the antennas (more filtre Mayer be requeres)

Fil