Works great. All the original lights for the 4 switches work but the LED for the mod at the top does not. When the switch is down it is in double preset mode. Push switch you want to program, set a sound. Then push switch at top. Change parameters of the same sound. You cannot change from mod delay to echoplex but rather from echoplex short delay to echoplex long delay. Then press and hold the original selected preset switch on bottom row until it blinks. All done. When switch is in up position I do not know what this does. I believe it to be an expression mod as there is a cable connected to the expression jack on the back but I never figured out how to work it. This unit has been well loved as you can see which means its a good one that needs to be played. Not for the shelf but for the stage. Enjoy!