strange cable noise

[John Matrix]

Some of my instrument cables have started acting strangely. These are the cables I use in my effects loop. When I touch the cables I can hear a knocking sound come though the amp. Like, the physical sound of me tapping the cable comes though.

I've tried these cables in other places in my chain and it is not nearly as noticeable. I've tried other cables in the effects loop and not had this problem. What could be causing this? I've never had this kind of issue before.

[crochambeau]

High capacitance cable sometimes "induces" a voltage change when the two conductors (separated by dielectric, hence the capacitor) are moved or stressed in relation to one another. This is the same principal as that what is employed by condenser (capacitor) microphones, just on a different scale. I'm guessing you really hear it when feeding a high gain or inherently "reactive" circuit. All my wire is the same way, I find it a joy to use, but I also tend to make noise/open ended music, so... YMMV.

I'd mark the ones that like to chat with you and place them in the positions of your liking.

[John Matrix]

It's strange because I've been using these cables for like 2 years in the same way and I only just now noticed this issue. It's definitely possible that it's been doing it this whole time, but do you think there is a chance that the cables could have gotten damaged?

[crochambeau]

I've never observed cables going microphonic due to damage, though I certainly would not conclude the failure mode impossible. My own experience with cable failure just ranges from the obvious open cable to heavily oxidized wire exhibiting enough resistance to dull the wire.. (my microphonics are built in, based on a very high capacitance wire I have a few spools of)

[John Matrix]

Cool, well thanks for the info. The cables still work so I guess I'll just rotate them out of my gigging equipment and use em at home.