I wonder if you guys (generic term) could advise me on the problem I
am having. I am digitising hundreds of cassette tapes using a
Behringer UCA202. These are from the 1970s and are Ferro, Sony,
Scotch, Boots (own brand), BASF. Most are C120, some are C60.

I'm using a brand new Pioneer dual cassette deck with auto reverse -
in the hope of leaving it working unattended for a few hours at a
time. .

But the quality goes down, the level goes down, and the sound become
muffled after about a few have gone though. I think that they are
suffering from sticky-shed and clogging the heads.. Can I bake the
cassettes to make them more playable. I've tried tape head cleaners
but these do not really work.

Thank you - Chris B.