I recently fixed up a Sony WM-3 after i found it rummaging in my basement. I replaced the belts and the pinch rollers and cleaned the head with 91% isopropyl alcohol and relubed the capstan bearings and the motor. But on playback of any given tape i have, the high ends are terrible! Even if my volume is on the lower end, crashes from symbols as such are nearly deafening. I listened to the same cassettes on my three other walkmans and my tape deck but they all sounded just fine. Anyone have any idea what could be causing this? (Recorded and played back without dolby)