Hi, welcome to the forum. So you didn't read the manual and decided to post here for help? Good decision
. You've saved a lot of time.
I'll try to have my explanation as easy-to-understand as possible. Ready?
First, switch on your A-500 Pro and press the left arrow button until you see "CTRL MAP" on the LCD display. Next, turn the Value knob and choose "12," which will display "Live SOLO" momentarily. I'll explain the detail later, but you have just selected a control map (#12) Roland has prepared specifically for Ableton Live.
Now, on your PC, go to Program Files\Roland\A-PRO EDITOR and double-click AProEditor.exe, which launches the A-PRO Editor that allows you to edit the maps stored in the hardware. To edit a control map using this editor, you first have to send the map to edit from the hardware to the A-Pro editor, which can be done easily by selecting "12" from the Control Map pull-down in the upper right corner and clicking the Receive button (press Continue). After clicking the button, the display on your A-500 Pro shows "Transmitting…" and the Title field of the editor says, “Live SOLO,” which means the map data was successfully transmitted to the editor.
Next, click the R1 knob on the editor, which opens a dialog box. As you can see, the Assign Message pull-down is showing “Channel Message” and the Control Number field is showing “16,” which means that the R1 knob of your A-500 Pro, when tweaked by you, sends the Control Change #16 to your PC (DAW). And if, for example, you assigned the R1 knob to the Live’s first track’s pan knob, it means that you have bound CC#16 and the pan knob. If you change the control number on the editor from 16 to something else, the R1 knob will no longer be able to control the track’s pan knob. Clear so far?
Before moving onto the next step, I want to know which control map in the A-Pro hardware you've been using. This is easy to check. When you switch on your A-500Pro, press the left arrow button until you see "CTRL MAP" on the LCD display, which you already did earlier. Which map is shown there? By default, A-Pro automatically selects the map 0 (Sonar ACT Map) when powered on. A-Pro has 20 control maps (0-19) and they contain different mappings (for example, the maps for Live use CC#16 for the R1 knob, while Sonar maps use CC#74). Don’t ask me why they use different maps, but you should probably use the Live maps (12-14) for convenience. And, if you want the A-Pro hardware to automatically select one of Live maps on startup, follow these steps:
1. Simultaneously press the ACT button and the left arrow button.
2. Turn the Value knob and choose “System Setting,” then press the Value knob.
3. Turn the Value knob again and choose “LAST ACCMAP,” and press the Value knob to exit. By this, the map you’re using when powering off your A-500Pro will be automatically called up the next time you power on the device.
If you’re wondering whether you’ll have to edit the default MIDI messages using the A-Pro editor, I’ll show you one example. Let’s go back to the Live SOLO map and click the Express (P2) on the editor. As you can see, nothing is assigned to this control. This means, if you have an expression pedal and want to use it to control, for example, rotary speaker speed in an organ preset, you’ll have to assign CC#1 (modulation) to this control. So, if you don’t use pedals and are happy with the default message assignments in the Live maps, you won’t have to edit anything. If you do edit and want to save the map as a file, go to File > Save As on the editor. By the way, files for the default maps #1-18 are downloadable from the Roland official site. If you use these files, you won’t have to do the transmission from the A-Pro hardware to the A-Pro Editor.
http://www.rolandus.com/support/search/A-500PRO A-PRO Series Preset Control Map v1.10
Now, let me answer your questions.
Question 1
Clicking on the knob on the A-Pro editor opens a dialog box, which shows its MIDI channel.
Question 2&3
I’m afraid I don’t use Live (I use Sonar and Studio One), so I cannot answer these questions. Maybe you should check or post in the Live forum?
I don’t know if I explained everything you need, but lastly I want to mention about the A-Pro’s two input ports: A-Pro 1 and A-Pro 2. When you play the A-Pro keyboard, information such as note, pitch, and after touch messages will be sent through A-Pro 1. When you tweak the knobs, sliders, buttons, and pads, the various messages assigned to them will be sent through A-Pro 2. ALWAYS choose “A-Pro 1” for your MIDI track inputs, and chose “A-Pro 2” for the input port (and “A-Pro” for the output port) in the control surface setting page in Live.
Hope this helped.