Can a piece of hardware avoid shorting a pc sound card?

[sirgilmour]

I have fried 2 pc sound cards by plugging a stereo jack into a pc sound card because the soundblasters were not turned off (I have my pc configured to play all around my appartement so i have 3 devices to power off) And with a buzzing noise there is no more music coming from the motherboard's green jack, front and back. 

And I bought this brand new PC that I would not want to break, i tried a usb sound card but the sound is 30% lower and weaker.

I read about ground loop noise isolator, but it says it's mainly for devices that have static sound when plugged to a pc like a nintendo switch, question is does it prevent shorting motherboard soundcard and does it make music less rich in sound.

I'm open to other suggestions to find a way not to fear making a mistake and breaking this new pc.

Thanks

[Geek-9pm]

Your said:

I read about ground loop noise isolator, but it says it's mainly for devices that have static sound when plugged to a pc like a nintendo switch, question is does it prevent shorting motherboard soundcard and does it make music less rich in sound.

Not true.
Explaining ground loops is not easy. General rule unplug everything before you do anything. Some types of audio connectors have protection. But not the min plugs.
Just  a small leakage of AC power destroys many  semiconductors.

[Lisa_maree]

If there is enough voltage either from a earth loop or a fault in the sound blaster speakers then there is a fault with the speakers. The sound adapter on the motherboard output is capacitively coupled to afford protection from earth loops and dc voltages. If you have a earth loop the audio would be very distorted but should not damage the output.
what about using Bluetooth between the computer and speakers. 

[sirgilmour]

Bluetooth can't be as good as a direct link to the audio card. Can it?

[DaveLembke]

And I bought this brand new PC that I would not want to break, i tried a usb sound card but the sound is 30% lower and weaker.

Curious the type of speakers the Sound Blaster speakers are... do they have where they are powered by USB power or a wall adapter or are they the really old early to mid 1990s type that play sound direct requiring the audio output to drive the speakers? If its the older style I highly suggest replacing them with the newer style that are not just a set of speakers connected to audio jack but ones that have their own power supply or USB power connection and amplifier circuit in them to drive the sound without loading down heavily on the audio amplifier of modern sound cards that aren't a good match for legacy speakers lacking a built in amplifier.

The original sound blaster cards had an audio output jack that was set to a higher output to be able to drive speakers without requirement of a set of speakers to have their own amplifier. A sign of wrong legacy speakers paired with modern is that the volume is drastically reduced as modern audio amplifiers are suppose to be paired with modern speakers with built in amplifier and only speakers directly driven would be a headset.

[sirgilmour]

Tried a General Electric bluetooth transmiter and the sound is amazing. Case closed, no chance of killing the motherboard. I would even buy a plug to prevent any use to the audio holes haha, does it exist? am I getting too paranoid?

Bluetooth correction. Noticed a few lags, like the first second of youtube videos with no sound and a glitch listening to a sound, tried going back to see if the file was corrupted and it was not

I would have loved to make a few bucks selling my previous pcs, but who would want a soundless pc... I would be ashamed to even put them on sale

[Geek-9pm]

https://ieeexplore.ieee.org/book/5452231
Grounds for Grounding: A Circuit to System Handbook

The above reference is a very good book about grounding as said applies to electrical and electronic systems. Along the best and newest books about this subject.
But I do not mean to suggest that the subject is not understood. The subject has been well understood for a long time. The hard part is getting people to do anything about it because it seems to be too expensive or too hard to accomplish.
Basically, what you have to do is to just improve the kind of equipment that you have so that it conforms to modern-day standards for electrical and electronic equipment. In a nutshell, that's it.
I do not wish to add any more to this thread because we end up getting a lot of antidote viewpoints about how to take care of the problem. The basic answer is you have to do something about it if you wanted to get better. But most people, or maybe I should say few people, choose to do nothing and then complain about it.
I will stop my rent here.