🚀 go-pugleaf

This sounds like a problem I had with my walkman (different brand).  It
seemed to be playing at a slower than normal speed for no particular
reason.  I thought it might be the fact that I was using rechargable
batteries, but the problem persisted when I rigged up a 3v dc power
supply from an ac adapter.  I ended up opening the case and found a tiny
potentiometer that was for the purpose of adjusting the motor speed. 
This pot is accessible through a hole in the back cover with a jewlers
screwdriver so I won't need to open the case to adjust the speed again. 
I adjusted the speed until I thought it sounded right, but the most
accurate way to do it would be to make a cassette tape recording of a
1khz sine wave from a function generator and play it in the walkman. 
Observe the audio output on a scope and adjust the motor speed until the
output frequency matches the frequency you recorded on the tape.

Todd Ferrante