Instrument, Mic and Line Level Differences | Shure

Hi,
(1) Is it okay to connect the output from a 50-watt guitar amplifier headphone port to a line-in input port on a mixer?
(2) Also, is it okay to connect the output from a 50-watt guitar amplifier headphone port to a line-in input port on a PC sound card?

When I did (2) the PC sound card quite literally got fried up.
But for (1), the mixer didn't get burnt up and everything functioned normally.
What's the difference actually between the two scenarios?
Afterall both had the same signal from the headphones output port going into a line-level input port.

Great explanation! I LOVE Shure products. I have a few decent mics, but my favorite mics to record my string acoustic guitars (Taylor 814ce and Cordoba Studio ) are a pair of SM81s. They are magical! Thanks for all the free t-shirts at NAMM over the years. 🙂

Great! Thanks.

Hello

Am looking for some suggestions

Have a Shure MVi Digital Audio Interface

Am looking for an earset head-worn microphone that will connect with the interface. Wish to use it for conference calls as my home office has a lot of echo

Was checking the Shure MX153
But am not sure whether it will connect directly into the above interface

Are any connectors available for the same or maybe you could suggest any other earset head-worn microphone which will directly fit into the Shure MVi Digital Audio Interface?