tape screech

[aadam jacobs]

I'm new here, so I don't know if this has been covered.
When I've dealt with old, cheap tapes screeching I've found the following to work:
FF & REW a bunch of times before playing. If that doesn't loosen things up enough, try loosening the screws on the tape shell just a very little bit.
No screws? Transfer the tape to a new shell with screws. The old tape's shell will need to be carefully broken to free it. 
This is a delicate job, and it's better to have experience before working with a valuable recording.

I'm glad to see the transfers are being done on quality decks like Naks, but are each of the tapes being played at optimum playback head azymuth?
Azymuth is head alignment, and is done automatically on Nakmichi's Dragon and manually on other models. 
It can be done on any cassette deck with a jeweler's screwdriver. 
Much of the loss of sound quality can be attributed to tapes being played on decks without the azymuth optimized for that tape.
Symtoms are loss of high end, a muddyness to the sound. It can easily be changed with excellent results by ear, no outboard equipment necessary.

There are probably websites devoted to this....

Happy listening.
Aadam