Mono / stereo jacks & cables compatibility question

So this has never been clear to me…

Is it possible to harm a device by using the wrong cable?

Here are some info i’ve gathered thru the net. Please tell me what is true or false:

-nowadays most device are protected
-using a mono jack with a stereo input is ok
-using a stereo jack with a mono input is ok
-using a stereo jack with a mono output is ok
-using a mono jack with stereo output is NOT ok


Input protected? I don’t know about that. But it should handle any reasonable output from another device (an exception being modular signals, for example, well above normal audio levels)

Yes, it just shorts the right input to ground
Yes, you’ll just get nothing on the right channel of the stereo cable.

I wouldn’t assume so. Some things are okay with it, others not. I wouldn’t do it unless it specifically says it’s okay.

@beefinator is correct - not worth risking it.

It amazes me to see guys with thousands worth of modular using cheap crappy cables and adaptors, or those stacking jacks, of course it will often work ok but then the one time when something goes wrong the expense of the repair will be more that using the proper cables in the first place, a false economy.

Cheap cables are the bane of my existence.