Usb cable shootout

[One and a half]

5 hours ago, audiobomber said:

There's no doubt that ferrite cores work, and that they can be tuned, via magnetic properties and placement. It makes sense that moving a ferrite core along the cable would change the frequency of affected wavelengths, impacting the RFI that the downstream machine sees. That's why manufacturers add them to USB cables.

 

I only put ferrites on AC and DC cables, not on analog or digital data cables, because without proper engineering it is a crap shoot; could benefit, could do harm. An AC or DC cable for audio should never have anything higher than 60Hz riding on it, and ferrites operate at far higher frequencies, so a core can't hurt and may help.

 

Of course you could add a movable silencer, as Stealth and iFi have done, and listen for results, but it seems a bit too random for me to bother. EMI/RFI is not constant, it changes depending on which devices are radiating and their locations. I notice that in the latest cables, iFi has dropped the movable silencer.

To make things easier,  conducted noise ends at 30 MHz (in wires EMC) , above that frequency,  noise is radiated through air (RFI).

The hard part is to determine what the conducted noise frequency is, and then where does it come from.  

 

Image problems are usually attributed to noise from a USB source, also brightness from the source. Even 'high' quality USB eg from my Lumin U1 can change with different USB cables and USB fixer-uppers.

[One and a half]

On 8/25/2023 at 5:48 AM, One and a half said:

 mage problems are usually attributed to noise from a USB source, also brightness from the source. Even 'high' quality USB eg from my Lumin U1 can change with different USB cables and USB fixer-uppers.

 

There's a  a correction here with this statement. When the audio system was in the other part of the house, a Topz transformer was used on the front end of all AC supplies. With the audio equipment in another room, an Equitech 1RQ replaced the Topaz transformer. The imaging wasn't quite right, though the speaker toe in wasn't right, so measured the angles and distances, they were OK, but the image suffered suckout from centre to either left and right speaker.

 

The Intona 7504, ifi Micro usB3, Nordost blue heaven cables, and the 9V linear supply, were all removed, a single Acoustic Revive split USB cable then connected the Lumin U1 to the DAC.  Everything else remained the same.

Dang, the image was restored, and gained a little height too on very ordinary recordings, very happy with the results.

 

Conclusion, the type of USB cable depends on the AC quality.