@almarg
I'm aware that some cables are designed to be highly reactive. I seriously doubt any cable could cause a sudden onset of an undesirable characteristic. A cable may attenuate the problem, but not cure it.
If I was suddenly having this problem the first thing I'd look for is DC on the outputs. Next I'd verify rail voltage on the power supply and give a good visual inspection of all the discreet components. I'd do the basics to rule out the amp because that's the most likely culprit.
I'm aware that some cables are designed to be highly reactive. I seriously doubt any cable could cause a sudden onset of an undesirable characteristic. A cable may attenuate the problem, but not cure it.
If I was suddenly having this problem the first thing I'd look for is DC on the outputs. Next I'd verify rail voltage on the power supply and give a good visual inspection of all the discreet components. I'd do the basics to rule out the amp because that's the most likely culprit.