Overall Isolation - network, USB, and power

[asdf1000]

On 25/01/2018 at 5:33 AM, One and a half said:

On the other hand ferrites on USB are really bad, they screw up the waveform. 

 

A different viewpoint from Rob Watts, on ferrites used with USB cables:

 

"What USB cables are best?

So what are the best USB cables? Firstly, be careful. A lot of audiophile USB cables actually increase RF noise and make it sound brighter, and superficially impressive - but this is just distortion brightening things up. Go for USB cables that have ferrites in the cable is a good idea - it may also solve any RF issues from the mobile that you may have too."
 

https://www.head-fi.org/threads/chord-electronics-dave.766517/page-94#post-12262339

 

[asdf1000]

25 minutes ago, One and a half said:

but! The noise seriously screws with imaging and once the symptoms are known

 

Noted. Just presenting the views of one of the better DAC designers out there. Lots of differing opinions out there regarding USB cables in general, even amongst the experts...

 

Who to believe!? Our own ears I guess.

 

[asdf1000]

Another quote from Rob on ferrites used with digital cables in general:

 

"Ferrites on digital cables have absolutely no down-side technically. But for analogue cables, proceed with extreme care, as ferrites, like all magnetic materials, have non-linearities, and the benefits may be be much smaller than the problems of the non-linearities. Principally we have two problems:
1. Hysteresis - this will cause straightforward high frequency distortion, and timing distortion, as signal delays depend upon previous activity. Both effects are highly audible.
2. Inductor saturation. As current flows in an inductor, the inductance value reduces with current; this in turn changes the phase angle, so the delay varies with current amplitude. This creates PIM (phase intermodulation distortion) and also creates non-linear timing errors too. Again, this effect is highly audible with large currents (loudspeaker outputs) on both inductors and in-circuit ferrites.

Experience has taught me not to use inductors or ferrite beads in-circuit with analogue, because of these problems, as they are directly measurable (with loudspeaker outputs), and certainly audible. The large ferrite cylinders are less of a problem, but nonetheless don't assume that a ferrite that is good on digital will be equally good on analogue."

 

 

https://www.head-fi.org/threads/chord-electronics-blu-mk-2-the-official-thread.831343/page-107#post-13752481