TO RECALIBRATE MICRO 75B OR MICRO 75A FROM 60 TO 50 HZ

Lift off the turntable platter and install 50 hz strobe disk; set this off to the side to dry.

To remove the chassis from the case: stick a screwdriver under the chrome handle cover and snap it off. Remove the 2 screws holding the handle, and the 2 rubber feet on the opposite side. The chassis will now slide out of the case.

Turn the Amplifier chassis up side down, control panel away from you, on a pillow or soft foam to protect the tone arm. Locate the speed control transport, the throwout (which disengages the motor in the off position), and the microswitch that turns off the motor when the speed control is in the off position (see drawing below). Loosen the 2 nuts holding the throwout and slide it all the way to the right, out of the way. Loosen the nut holding the microswitch and rotate it so that it is out of the way, away from the motor.

Set the unit on its side, so you can see and reach both the top and underside of the system. Move the speed control so that the white knob is pointing at 52 r.p.m. (this should be the speed at which you currently have to set the system in order to play 45 r.p.m. records). Note the position of the motor and speed control transport; this is the position you want the motor and speed control transport to be in when the white knob is pointing at 45 r.p.m.

Holding the motor in place, loosen the 2 screws on the speed control transport and move the white knob to 45 r.p.m. and then lightly retighten the 2 screws.

Before checking if the speed is set correctly, get a couple of thin books or magazines to set under the sides of the unit: (this is necessary because the long screw that adjusts the motor spring tension extends below the bottom of the unit). Now you can plug in the power cord, put on the platter, and check if the speed is set correctly. If more adjusting is necessary be sure to unplug the power cord before readjusting the 2 screws on the speed control transport. Do this as many times as necessary to get the speed set correctly. Only when the speed is correct should you firmly tighten these 2 screws.

BE SURE THE SPEED IS ADJUSTED CORRECTLY BEFORE PROCEEDING

Now that the speed is set correctly unplug the unit, move the white knob to the off position, and turn it over again on the pillow or foam. Rotate the microswitch until there is about 1/16 inch of clearance between the leaf and the body of the switch (see drawing). Retighten the nut.

page 2 "TO RECALIBRATE MICRO 75A OR MICRO 75B FROM 60 TO 50 HZ

Keep the speed control in the off position, and lift the motor so that you can slide the throwout back to the left until the motor mount (metal piece) rests on the ledge shown in the drawing. This holds the drive wheel away from the platter in the off position. Retighten the nuts so that they are firm but not extremely tight. If you overtighten them the speed control will bind and not move freely.

Turn the unit right side up, plug in the power cord, and turn it on. Check to be sure that the turntable strobes correctly; that the motor turns off when the speed control knob is in the off position, that the speed control moves freely, and that the drive wheel disengages from the platter when the speed control knob is in the off position.

Reinstall the chassis in the case and the job is finished. (recal60-50hz.75aorb)