I recently fetched my father's old cassette deck from the basement, and with it I bought some Maxell cassettes. I started recording some songs from my computer to one cassette tape, which worked perfectly. But today, the cassettes I recorded started to sound dull at some parts. I checked the tape and there were some visible scratches along the tape. I don't know why this wasn't a problem yesterday. I tried recording another cassette tape but that one became scratched as well.
Do you guys have any tips how to prevent this damage? Any help would be of great value since I practically know nothing about cassettes nor cassette decks (yet)!
My scratched cassette tape: https://imgur.com/a/pbC5k8d
My cassette deck: https://www.hifiengine.com/manual_library/technics/rs-b555.shtml
Cassette tapes I used: https://www.ebay.com/itm/NEW-Maxell-UR90-90-Minutes-Blank-Audio-Media-Recording- Cassette-Tapes-5-Pack-/291829803600?ef_id=EAIaIQobChMI99LDkdC_5gIVjKiaCh0hdA5CEA QYAiABEgKkiPD_BwE:G:s