It's easier to start with an organ that's only one part and has mod wheel opposite of what you want.

Much of this general navigation is covered here: https://www.yamahasynth.com/modx-category/mastering-modx-navigation-tips

Recall one of those Performances.

Use the touchscreen to touch the PART (only part there) from the [PERFORMANCE] (aka HOME) screen. It's one of those vertical rectangles under the Performance name.

A menu will pop up - choose "Edit".

"Common" (lower left) should be selected by default. Touch the touchscreen (left hand side) "Mod/Control" -> "Control Assign".

In the upper-left there should be a button "Auto Select" - make sure it's green.

Now move the Mod Wheel. The parameters assigned to Mod Wheel should show up automatically after moving. You should see a rotor speed. If that is not the selected destination, press it to select. You're going to want to reverse the curve so the parameter is changed in the opposite direction. You could use user curves to draw a curve that is opposite what you see on the screen - or pick a preset curve that will mimic this. What this does is still adds to the default programmed value - but reverses the direction. All the way down will be adding maximum and all the way up (rotation of MW) will add the minimum.

You could also change the polarity of the curve that is presented (usually it's a positive ramp) to a negative one. You'd also have to go and adjust the default programmed value for the rotor speed and increase the value. If the curve was positive, the default is likely 0. When you switch to negative, you should set the default to 127 (or some high value). Since now you are subtracting instead of adding to the number.

I can put something more specific (an actual organ and running through) once I get the keyboard setup. Unless someone else beats me to it. That's the general rundown.

Really good information. Thank you. I'll work on it.

Got to the "now move mod wheel" When I do there is no visual change on the display. There are 4 destinations and I tried pushing buttons for all 4 but nothing happened. Tried to attached a picture

You didn't say which organ Performance this is - which would help in syncing up on this side to what you're doing.

I just ran through the tone-wheel organs until I found one that matched the opposite modwheel programming. Most are setup so pushing the modwheel "up" makes the rotary speaker speed up. It took a while, but "The Preacher" was the first with an opposite setting. The mod wheel is only assigned to one parameter - so editing this one should be an easy starter. The default ratio is -30. Which you would change to +30.

You notice the destination is "InsA SpdCtrl". The next task is to go to the InsA parameters and change the default for SpdCtrl.

"Effect" -> "Ins A". Change the "Speed Control" setting from "Fast" to "Slow". The reason why is that our mod wheel is going to ADD now instead of subtracting. This does two things. 1) It changes the default speed of the rotary speaker from fast to slow when you change to this Performance. 2) It sets up the default to slow which, when added to will change to fast. If it was "fast" - you cannot add anything to "fast" to make it turn slow.

This is all for this Performance to change the modwheel polarity.

If you wanted the default to still be FAST when you loaded the performance - but have "up" as fast and "down" (modwheel rotation) as slow -- then this is possible. You would need to change the curve type. I'm assuming this is not what you want -- so won't get into that.

Many organ parts default the mod wheel as fast rotor in down position and slow on up position. I want all my organ parts to start slow and be pushed up to fast position. I have been able to get to the page showing mod wheel settings but need to know where the setting is to switch up/down settings. (and also to possibly set the speed of the fast setting) Guess this is a two part question. Can someone assist me with this?

The Mod Wheel is a controller that defaults to 0 And when it sends values they run from 0 and increase toward 127 as you raise it.

This matches the movement needed to change the Rotary Speaker “Speed Control” from the “Slow” setting to the “Fast” setting. This parameter is a two-position SWITCH (Slow to mimic the Leslie 'Chorale' setting, and Fast to mimic the Leslie 'Tremolo' setting). When a linear curve is used, all values 0-63 = Slow, and all values 64-127 = Fast.

The setting that determines this is the “Speed Control”. If you want all the organs set so the Rotary Speaker goes from Slow-to-Fast as you raise the MW, simply change the initial Speed Control to “Slow”. Then [STORE] your version of the Organ.

When you do the Control Assign screen would look like this:

The Curve would look like the screenshot below when switching a "Speed Control" = Fast...toward Slow. If set Fast then you must apply a negative value to the MW movement. You can understand the Negative Ratio as reducing Fast-to-Slow... as you raise the wheel you are applying negative values thus decreasing the value:

I'm afraid I'm getting myself in deep here. Here are my problems. ( this all pertains to "The Preacher" performance
1. When I Highlight Auto select I never see anything move on the screen. I do not know if there is a setting that needs to be turned on but I see nothing.
2. when I press organ tone wheel (1), edit, Mod control, control assign...I only have 1 destination (InsA SpdCntrl).
A. If I change ratio from -30 to +30 I get fast rotor with wheel up or down.
B. If I try to add a destination it goes to destination 15 (cannot change to any other destination on this screen.
3 I am also searching for rotor speed control and as of now cannot find where it is.
I would appreciate help on this.

When you press "Auto Select" so it is green like in the screenshot from BM, you then have to move a controller to see things change. Move the modwheel. Any assignments associated with the modwheel will be displayed. Make sure the [ASSIGN] button (to the left of the 4 knobs) is lit as in this picture (courtesy pjd):

Then spin each of the 4 assignable knobs. You should see destinations change which are assigned to each knob.

If a controller has no destination assigned - you may not see a change between that controller and another without any assignment.

A. If I change ratio from -30 to +30 I get fast rotor with wheel up or down.

You skipped a step. Not only do you need to change the ratio so it ADDs instead of SUBTRACTs - but you also need to adjust the starting value. Previous, when it was subtracting (a ratio of -30) - the starting value was a high value. Then moving the modwheel "up" subtracted from the high number.

If you change the modwheel to ADD - then without editing the initial parameter value - you will be adding to a high a number. There will be no change. You really need to edit that initial value. Change the speed from "Fast" to "Slow". Following these initial instructions:

From the PART edit ...

"Effect" -> "Ins A". Change the "Speed Control" setting from "Fast" to "Slow". The reason why is that our mod wheel is going to ADD now instead of subtracting. This does two things. 1) It changes the default speed of the rotary speaker from fast to slow when you change to this Performance. 2) It sets up the default to slow which, when added to will change to fast. If it was "fast" - you cannot add anything to "fast" to make it turn slow.

From this screen, you would press "Effect" then, the next level of menu, select "Ins A". You will see the "Fast" setting and change this to "Slow".