Two of my Sony units have these motors. The manual specifies that the speed can be adjusted from the back of the motor itself, not from a separate potentiometer. Unfortunately the hole in the back is "plugged" with some kind of rubber/glue. How are we supposed to adjust the speed of the motor. (My calibration tape generates a 3160 signal, wich is grossly out of spec.)
Assuming there's isn't a separate trimpot on a board (which I don't think is the case given the motor has 2 wires), you have to put a flat screwdriver through that hole and push it until you reach the trimpot inside. No worries as it will go through that rubber no problem, it's cut specifically for that.
It's curious : I have another boombox (sony cfs w308) with a similar motor, this one has three wires AND a trimpot. So based on my 3 samples: 2wires>internal trimpot 3wires>external trimpot Does this make sense?
Seen units that have both internal and external trimpot. Usually the ones without internal have 4 wires, not 3. The ones with 3 wires don't think are that common, at least I've not seen them.
