One thing you might try is a kim conversion utility:http://retro.hansotten.nl/category/kim-1/page/5/http://dxforth.mirrors.minimaltype.com/#kimtape
KIMTAPE v0.5 - tape conversion utility for KIM-1 and SYM-1 (2004-05-17)
Similar to the KCS utility for Kansas City Standard tapes, KIMTAPE allows programs stored on cassette tape to be
decoded to a program file. It handles both MOS Technology KIM-1 and Synertek SYM-1 tape formats including
HYPERTAPE. The reverse process - converting a program file to an audio wavefile is also possible, allowing one to
produce perfectly regenerated cassettes. KIMTAPE works with 8-bit mono WAV, VOC or RAW audio files recorded
at 22050 samples per second.
Download: kimtap05.zip (MS-DOS)