Those links are incredibly basic and flawed. I am a professional audio engineer and part of my work is restoring a collection of radio programs from cassettes to digital.

The BIG thing left out of most silly Utube tutorials is how important it is to get accurate playback of the cassettes, whch will enhance the sound of the transfer and give them new life. It is important to be sure the playback head is aligned to the track on the tape. Some better quality decks Such as some Nakamichis) have a knob control to adjust the azimuth, and it ia easy to hear when they are in alignmnt - the treble gets better and pops into focus when the azmuth is properly aligned!

Azimuth can be adjusted on any deck, but it is quite difficult without the actual external cntrol, and you may damage yur cassette deck.