You'll probably start to notice a brownish discoloration on the pinch roll but I'd still do the heads every two songs or equivalent.

At one point I tried to play back the Gambler album when it got old and the tape just slowed it down to a stop. Just depends on the quality used in cassettes by the company. My old quarter in large reels have held up better that the cassettes over the years - never know, but it's fun recovering the old stuff - worth the effort. P.S. don't turn the demag on near any tape.

Cheers - Ian

Ian
My "Original Tunes" Site
My gene pool needs more chlorine.