Cassettes are no longer the popular format for listening to recordings, but many instructional and informational audio tapes still have not been transferred to CD or MP3. Speeding up the playback of these tapes lets you get through them faster, but cassette decks do not feature variable speed control. Changing the speed requires opening the cassette deck and adjusting the screw that controls the motor. It is not difficult, but care must be taken during this process.
Unplug all connections from the cassette deck. Put the cassette deck face down on a table. Pry the rubber feet off the bottom with the utility knife. Remove the screws from beneath the rubber feet and from the bottom with a screwdriver.
Turn the cassette deck face up and put it down on the table. Remove all of the screws from the top and sides and back using the screwdriver. Pull off the outer case of the cassette deck and place it aside.
Locate the motor, which should be next to the power supply. Locate the small silver screw that controls a potentiometer, which is on the circuit board next to the motor. Insert the flat-edged screwdriver into the screw and turn it slightly to the left.
Put the case back onto the cassette deck. Plug the power cord into a socket for power. Plug the headphone jack into the headphone output on the cassette deck.
Turn the cassette deck on. Insert a cassette and close the tray. Press "Play."
Determine whether the speed of the recording is faster or slower than normal. If it is slower but not slow enough (or faster but not fast enough), slightly adjust the silver screw in the same direction as you did before. If the recording is slower (or faster) and you want the opposite result, turn the silver screw in the other direction.
Improper adjustment of the motor speed can damage the cassette deck and cause it to cease working.