You can build your own organ, or a full drawbar organ, B3... whatever.

Have a look at the first few Organ Presets - then have a look at their Elements. The elements are footages... and called as such 16', 8' etc. You set your Faders to Element control, instead of Part and they become drawbars. You can build a two Part B3 with all the footages, rotor noise, percussion etc.

If you want to spend money EasySounds and KaPro are pretty reliable.

You might have better luck using http://soundmondo.martintarenskeen.nl/ to use the soundmondo "patches".

If you're building your own - you can recall any single-Part organ Performance you otherwise like and turn OFF all of the active elements (except elements 1 and 2 - these should be ON). Then replace element 1 with the Waveform "Draw 16' " and replace element 2 with the Waveform "Draw 1' ". Adjust the levels of each element and make sure the element note range and velocity range covers the full keyboard and velocity range (since you'd be inheriting programming).

Wow, that's a great link for people like me who can't connect to Soundmondo Jason! I'll also experiment using elements for drawbars, as you both suggest.

Do you know how to load these .syz files from http://soundmondo.martintarenskeen.nl into my MODX? (on this website it says "To use the patches you can use the editor/librarian panels that I created for Ctrlr. But you can also use any SysEx dump utility", but frankly this doesn't make any sense to me)

On windows I would use MIDI-OX. Configure to only I/O to/from my MODX (if I had multiple MIDI devices). Then use the Sysex tab to send the .syz file to MODX.

While I’m really happy with my new MODX8, the organ sounds are quite weak and limited. E.g., I find it quite disappointing and strange that drawbars settings like 800000008 (16’ + 1’) seem to be completely missing.

There is a Performance called "All 9 Bars!" which is setup specifically to allow you to create any organ registration you want. Make sure your sliders are set to "Element/Operator" rather than "Part". Then activate Part 1, and the Sliders will let you set the first 8 drawbars (toggle them between 1-4 and 5-8), so to get the registration you asked about for example, you would put set the first drawbar to maximum (127) and the other seven to minimum (0).To adjust the 9th drawbar, switch to Part 2, and use the first slider. (Remaining sliders are also available for other adjustable attributes of the sound.) Then Store your modified Performance with a name like Organ 16’ + 1’ or whatever you'd like.

To achieve any registration you may be after, the 0 setting is easy, it's 0, and the full-out setting of 8 is easy, it's 127. To approximate the ones in between, you'll have to divide the 127 possible values by 9 to get any idea of where the in-between steps would fall.

I find it quite disappointing and strange that drawbars settings like 800000008 (16’ + 1’) seem to be completely missing.

This particular drawbar setting is so much a fundamental part of the B3 lexicon that it exists as its own MODX Waveform!

The possibility of building your own Tone Wheel organs is one of the reasons you purchased a music synthesizer (building your own...) particularly if you are not happy with those provided - it is an endeavor that is worth the effort. On this very point, we highly recommend you spend a bit of time with the basics of programming the MODX -- especially the article referenced below which is apart of the Super Knob programming series "Mastering MODX":

To get you started - let's say you wanted to build an organ sound that started with 800000008 (16' + 1')
From the HOME screen
Press [CATEGORY]
Set "Bank/Favorite" = All
Set "Attribute" = All
Under "Main" find and select "Init" > touch "Init Normal (AWM2)"
This is how you would initialize a Performance for construction

It places Waveform 0001 (happens to be an acoustic piano) in Element 1 -- with an organ envelope (immediate attack at key on, immediate release at key off)
First we will replace that acoustic piano Waveform with the Waveform that reproduces this classic organ tone...

Press [HOME]
In the screen, tap the "Type/Name" box for Part 1
A pop-in menu appears > select "Edit"
A "Part 1 - Edit' screen will appear
Along the bottom of the screen touch "Elem1" to view the first Oscillator's parameters.

Touch "Osc/Tune"
At the top of this screen is the assigned (default) Waveform - if you touch that box, a pop-in menu appears
Select "Category Search"
the amber "Waveform Category Search" appears.
Select Main - "Organ" > SubCategory = "Tone Wheel"

Here you will find all the different B3 organ Waveforms (not only are each individual Drawbar footage available, there are different combinations that can be used to construct a specific organ tone. Common setting like the first 4 drawbars full out ( "1st Four" ) allow you to reproduce this jazz setting with a single Oscillator (using 1 note of polyphony per note played) instead of using four Elements to do the same thing,

- scroll down and find "Gospel" __ the (16' + 1') is called a gospel organ sound in the B3 vocabulary...

Upon selecting it you will have the first building block in putting together an Organ sound...

Please see the following tutorial (link below) to one of the articles on programming the Super Knob and getting starting with thinking about putting together your own custom sounds.
The article covers morphing from the Gospel (16' + 1') to a B3 Jazz organ that has the first four drawbars at full 888800000 -- and the tutorial even walks you through applying a Rotary Speaker Speed Control...

We highly recommend the entire series but this one specifically address your first point:

Mastering MODX -- Controller Box Switches

Extra Credit:
Building an organ sound on a synth where you use 9 Oscillators (one for each drawbar) then setting seven of them at zero is about the most wasteful sound (from the polyphony usage viewpoint) that you can possibly build. It will sound exactly the same as the single Element that is a sample of the 16' and the 1' without having seven notes of polyphony to reproduce 0 output.

If you approach your B3 programming from knowing the exact footages and levels you wish to emulate, you can build organ tone that are far more efficient for what you wish to accomplish. Just FYI

Thank you all, it's clear that I've got some work to do!

Building an organ sound on a synth where you use 9 Oscillators (one for each drawbar) then setting seven of them at zero is about the most wasteful sound (from the polyphony usage viewpoint) that you can possibly build. It will sound exactly the same as the single Element that is a sample of the 16' and the 1' without having seven notes of polyphony to reproduce 0 output.

Great point. But in defense of that method of building one's desired organ registration (described in post #5)...

...it's faster and simpler (fewer steps and more easily set up in a matter of seconds)

...if ALL you're playing is organ (or if the only thing you're playing with it is an FM sound), polyphony is not likely to be an issue.

...you can easily do some drawbar manipulations as you play, without even having to set up superknob maneuvers in advance

Also, the amount of polyphony savings varies, and seven silent drawbars is pretty much a worst-case scenario. But yes, regardless of that, your preferred approach is certainly more polyphony-efficient... but sometimes quick and dirty gets the job done. 😉

...in defense of that method of building one's desired organ registration (described in post #5)...

I guess it needs a defense (lol)... but not really... "The Defense" doesn't change the point being made - it is about the most wasteful sound from a polyphony point of view - to program a drawbar to deliver 0 Part Volume. That is a fact. Opinions not withstanding. Knowledge of this FACT, can help you determine the best way to recreate the specific Drawbar settings you may need - and polyphony when building multiple PART Performances can be an issue.. If I'm doing a sound-alike sequence for "Green Onions" or "Whiter Shade of Pale", why use a sound with all 9 drawbar footages - If I know the specific Drawbar setting, I can program it efficiently for the specific use case.

Naturally, if you are going to 'work the drawbars' as a part of performing, then your preferred method is one of many ways to go... but the OP wanted specifically: 16' + 1' (Gospel)
Naturally, if you are going to be performing and you ONLY need the organ sound, then your preferred method can work... 100% agree
I don't really have a preferred method, just stating the facts on this one.

My only preference would be this, when working with a synthesizer, to make the most efficient use of the tools given... allows for flexibility elsewhere if I don't spend my polyphony unnecessarily.
And since the MONTAGE/MODX do not have actual Drawbars - the real time transition of settings can be done with the Motion Control engine's Super Knob/Assign Knob system - working efficiently can be worth the effort sometimes (down and dirty is great sometimes - but if you are going to customize your sounds for your own music - why not?

You could create a Whammy bar for any Electric guitar sound, but you don't need it on every guitar sound.
You can program all footages for your Tone Wheel organ sounds, but you don't need to do it on every organ sound. that I think is the only point.

If you chose all 9 bars as the starting point, I'd take Part 1 and turn off elements 3-8 then change element 2's waveform to the 1-foot Waveform. Yes, it's wasteful compared to a single-element organ where the sample already contains both 16' and 1'. However, it's far from the other extreme. And, in terms of time, doesn't take long. Then I'd delete the 2nd Part to get rid of leakage, 9th drawbar duplicate, noises, etc.

Now knowing what the "Gospel" waveform represents, I'd modify this to say turn off elements 2-8 and stick the "Gospel" waveform into element 1.

Still, I think "All 9!" has a lot of baggage to throw out. I'd really not start with "All 9" as I previously mentioned starting with a 1-Part organ instead.

Picking a 1-Part Performance as a starting point is easier. Like "The Preacher 2". "2" because this is the newer rotary speaker sim. Pick the non-" 2" one if you like the other rotary sim or just change the effects manually. Anyhow - turning off elements 2-8 (navigate to the "All" elements menu and press 2-8 so they go grey instead of green) then press "Draw 16' " (the only element still on) under "Waveform", pick "Category Search" then pull up the "Gospel" Waveform. [STORE], name, done.

The tutorial is OK too.

All of these ways are good. Do them all - figure out what works with you. Learn the keyboard. It's all fun no matter if you waste resources or sip them. Knowing the implications lets you have more fun.

That there are (at least) 4 different ways to arrive at your goal underlines the flexibility of the keyboard to cover many bases and bend to your particular way of working/playing.

If we're going to talk about the myriad of solutions, here's yet another... MODX has great features for integrating external sounds. VB3m is a really nice organ app that runs on iPhones and also many Android phones. So you can attach your smartphone via USB and create a single-part Performance that calls up your VB3m sound, and bring that sound up any time you want, either by itself, or split/layered with other MODX sounds. And since the MODX also acts as an audio interface, the organ sound will come in over that same USB connection and will be merged with the MODX sounds so it all comes out the same main audio out on the MODX.

[quotePost id=112947]
Extra Credit:
Building an organ sound on a synth where you use 9 Oscillators (one for each drawbar) then setting seven of them at zero is about the most wasteful sound (from the polyphony usage viewpoint) that you can possibly build.[/quotePost]
The zero elements can also simply be turned off, then they won't use polyphony.