Problem with cassette player that feeds into Audacity

[Mark]

i've been going through a load of tdk (CDingII and SA) that have now dried
up and won't roll well at all  - seems to be a combination of dry tape, the
slip sheets, bad hubs, terrible shell design... I've found that winding the
tape onto new hubs/shell (eg maxell UR which are stll readily available,
and have the clip-in hubs) works well enough to get a play or two.. get out
ye olde pencil and start winding!

but yes perhaps your deck needs new rubber (drive belt, idler wheels, pinch
roller) any of which deteriorate and can cause mad problems..