I have a particular cassette, rare for me to find a duplicate, that has a missing felt pressure pad. In fact it was missing the entire metal sled that the pad is attached to. I discovered this when I played the tape on my Sony TC-K700es and it sounded warbled and bad. I since then put the tape away, hoping I would find another or repair (actually I forgot about it for about a year). I was reading up on the Nakamichi 680 and (if I can remember correctly) certain models bypassed the use of a pressure pad during playback. Supposedly the creator of Nak implied the friction of the tape path rubbing against the pad induced unwanted sound (I guess he was pretty serious dude). Just remembering this article I popped the tape in and WOW, it plays perfectly. Anyone have anything to add about this?