So I got my TSR-8 out and running for the first time in a few years. I noticed it wouldn’t record on tracks 7 or 8 without severe volume drop and a muffled sound. So I cleaned the heads, started over. No change. Cleaned and demagged the heads... no change. So to investigate I played the entire tape, after which I saw an unusual buildup of oxide on the heads; like, cakes of it. I thought the old ampex tape I was using had finally given up on me. Next I cleaned the heads again and tried a newer (2013?) RMG tape. It worked better, but after a few song length playbacks I still see a buildup of oxide and it sounds muffled. So my question is, has anyone noticed sticky shed on RMG tapes, or is something in the tape path causing the oxide buildup?