I wonder if they ever tried duplicating a bad tape on a higher end audio double cassete deck, to a brand new tape.

It sounds like most of the devices used in the article would have low end quality motors, heads, etc. Such that a (still glitchy) copy on a new tape might read better.

I suppose it's possible the important bits of a high end cassete player aren't any better. Audiophile equipment is sometimes funny that way.

Edit: Found the full service manual for the Commodore 1530/1531 Datasette: ftp://www.zimmers.net/pub/cbm/schematics/datassette/C2N-1530-1531_Service_Manual_Preliminary_314002-002_(1984_Oct).pdf (hrm, guess HN doesn't linkify ftp:// urls?)