Congratulations on your purchase of the Hampton Motor Control HMC-MK1B. This unit was especially designed to turn older "single-speed" Leslie speakers into their newer "two-speed" counterpart.

The Hampton Motor Control performs this by synchronously switching (relative to 60Hz) the power on/off to the motor at precisely the right intervals to achieve reduced speeds from a single speed motor. Power is never interrupted when current is flowing through the motors to provide quiet operation (no switching noise on AC power, i.e. fed into amp). It DOES NOT achieve this by varying current or voltage applied to the motor as these methods can cause motor damage.

Each Hampton Motor Control unit has 4 DIP switches, located on the front of its case for selection of the slow speed. Switch #1 is the slowest and #4 the fastest. All units are factory set with the #2 switch on (up position) for standard slow speed.

NOTICE: Although the Hampton Motor Control is very easy to install and requires no modifications to your Leslie, your local Leslie service technician should install it and make final adjustments for optimum performance.

1. DISCONNECT POWER TO THE LESLIE. Allow one minute for residual voltages in the power amp to dissipate.
2. Remove the back panel(s) of the Leslie.
3. If the Leslie has not been maintained on a regular basis, remove the motor(s), brush them off, then wipe with a appropriate cleaner. Make sure that all old oil and dirt has been removed from the motor bearings and shaft before re-oiling with Leslie oil. This ensures smooth operation at slow speeds.
4. Remove top and bottom rotors, thoroughly clean and oil as described and step #3.
5. Replaced old, hard, or worn drive belts.
6. Position the Hampton Motor Control to the left of the 15" speaker. Make sure to have the DIP switch access hole/power cords facing the front. Fasten the unit down with the four #10 1/2" panhead wood screws provided. It may be necessary to drill small pilot holes first.
7. Select one on the four DIP switches as the pre-set slow speed. #2 is the standard slow. Select only one switch on (up), selecting more than one switch will cause the motors to run erratically at slow speed. Prolonged operation in this manner may cause damage to Hampton Motor Control Unit.
8. Unplug the two motors from the Leslie power amp and plug them into the white multiple outlet from the Hampton Motor Control unit.
9. Insert the unmarked (without red dot on end of plug) male ac plug from the Hampton Motor Control Unit into either outlet where the motors were plugged into.
10. Insert the male ac plug (with the red dot) from the Hampton Motor Control Unit into the courtesy outlet on the Leslie power amp (farthest right of the three). If the cords are reversed, the Leslie will run fast or off but no damage will occur.
11. Route the cables neatly up the left side of the existing Leslie cutout. Replace back panel(s) making sure the cords from the Hampton Motor Control Unit stay in the cutout and are not "pinched".
12. In most cases, the idler pulley (belt tensioner for top rotor) assembly will have to be re-adjusted to a lighter tension. Clean and oil as detailed in step #3.
13. Reconnect main cable and turn on the Leslie. The Leslie should run full speed when the foot switch is activated (as before), and the pre-selected slow speed when the switch is deactivated (instead of off). The Leslie should run very smooth at both speeds.
14. CONNECTING AN OSCILLOSCOPE TO THE OUTPUT OF THE HAMPTON MOTOR CONTROL WILL PERMANENTLY DAMAGE THE UNIT! This causes a very specific and detectable failure to the unit and voids the warranty.