Noise while switching selector switch

[nikhilji]

Newbie post here. I just finished replacing a cheapo input selector switch on my linestage with the one from glass-ware which has ground switching leads. I now get a loud noise when I switch between the inputs. Seems like the noise pulse is loud enough that I almost fear damaging the drivers on my speakers.

There have been couple of posts regarding this issue where some have suggested wiring a 10K resistor between the input and the output RCAs. Before I head down this road of blind experimentation, I also want to understand a bit of theory as to why this happens and the solution to fix this issue for my particular case. And yes, I do have output coupling caps in my line stage.

Thanks !

 

[DF96]

Switching ground leads seems a strange idea to me. I suppose it is an attempt to avoid hum loops and completely isolate unused items. However, if an item is left floating without a ground reference then it will generate noise when it is grounded again.

Maybe I have missed something, but this idea seems to be a foolish halfway house between unbalanced (switch signal only) and balanced (switch both signal lines). It forces an item to swap from getting its ground reference from the safety ground to the signal ground when selected. If these are different then you get switching noise; if they are the same then there is no point in switching the ground anyway. It is doing exactly what I would expect it to do!

 

[Bill Fuss]

You need a switch with make before break or "shorting" contacts. Ground switching is no big deal, you just need more poles, or sections, like a 4 position 4 pole.