Crackling noise with miniDSP after upgrading analog cables

[tjw59]

I use a miniDSP 2x4 since some years back. Wanted to improve my cabling, until now I have had some really inexpensive cables with bad fitting RCA-connectors.

Bought some double screened (copper braid and foil) low capacitive coaxial cable, Canford SDV-M. Had some goldplated RCA-connectors from Switchcraft that I soldered on.

I was most surprised to hear a crackling noise from my speakers. Did not matter if I had the new cables on the in- or outputs, same crackling. Tried another cable that I had around, RG62 with some nice plugs. Same noise. Switching back to the crap cable and it was all gone. Having the crap cables attached only at the power amps results in hum. The better cables attached that way are silent. Removing the miniDSP from the setup and having the new cables directly from the preamp to the power amps works very well.

Why do I get this crackling noise with the "better" cables together with the miniDSP 2x4?

For whatever it is worth. Have the same thing going on. To compound the oddness, using the very same cables I can plug into two different amplifiers. One hisses, the other doesn't. Never really been able to pin down why that is. Or why it is just that piece of equipment that exhibits the odd behavior. Can use the same two cables with any other output and they work fine. Finally just selected the cable that doesn't hiss and use it. Be interested to see if there is a solution beyond that!