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Best MIDI Organ Controller on the Market
Keyboard Controllers are great but usually can be lacking in control for an organ plug-in. You need "Drawbars", all "9" of them, and they need to be useful for controlling on-the-fly in real-time! Many of us have tried our fare with like, say, ...a Korg Nano-Controller or an actual keyboard controller with sliders, but most of the time they only come with 8 sliders (not 9), and those sliders were designed with controlling DAW faders in mind (not organ drawbars), ...AND you gotta MAP them.
So then ....enter GM Labs, an off-shoot project from GSi - Genuine Soundware Inc.'s Guido Scognamiglio. His first offering a few years ago was the D9U MIDI Organ Controller which is a basic "nine organ drawbars" MIDI controller. However, the latest and best offering is the D9X, a full organ MIDI controller with 9 drawbars plus an assortment of knobs and buttons to control other parameters such as Volume, Treble, Bass, Reverb, Percussion, Vibrato/Chorus, Rotary Speaker, and switching bewteen "Upper/Lower/Pedal" manuals. The physical controls are automatically "mapped" to the virtual controls for GSi's VB3 II Organ plug-in, but can be mapped to the controls for any brand/model of organ plug-in, ...or it can be used to control the parameters of any other "non"-organ plug-in (like pianos, electric pianos, synths).
To be honest, they are not inexpensive. However, the quality is superior (great feel on the organ drawbars) and they do offer the controller as a fully assembled unit or as an unassembled electronics kit (approx. $100 less). If you elect to assemble it from a kit, be prepared to do some basic components' soldering, ...however, the Arduino chip that runs it is already fully programmed (but is still fully customizable if you so choose).