Welcome to Yamaha Synth! Thanks for the question.

Frode wrote:

I'm trying to store a voice to User DR, but it won't give me that option, only User1-4. What am I missing here? The manual says it should be possible.

Here is what you are missing: There are two types of VOICES in your Motif XF: 1) Normal, 2) Drum Kit.

A Normal Voice contains a maximum of 8 Elements (oscillators) that can be used to build the single Voice Program. All 8 Elements are typically used to make a single instrument. An example of a Normal Voice would be "Full Concert Grand" - all 8 Elements are used to recreate a 9 foot, Yamaha CFIIIS concert grand acoustic piano.

A Drum Kit Voice contains a maximum of 73 Elements (oscillators) that are used to build the single Voice Program. Each of the 73 Elements is a separate instrument (or in some cases, a different articulation of a particular percussion instrument). An example would be where each Key is a separate percussion instrument, with the exception of the HiHat, which uses three keys to recreate three different strikes: Closed, Pedal, and Open, and the Triangle (Open and Mute), Guiro (2 different strokes, etc.)... Otherwise each Key is a different instrument. Articulations are typically "vertical" in the Drum Kit using velocity to trigger different samples.

Significantly, a Normal Voice and a Drum Kit Voice have different behaviors and a different set of edit parameters available: We like to say: there are "normal" musicians, and then there are "drummers"! 🙂

_ A Normal Voice will typically require you to press a key and hold it for the duration of time you want it to sound. Releasing the key sends the sound to the "Release Time" parameter to control how the sound disappears.
_ A Drum Kit Voice will typically require you to press a key to trigger the associated audio sample, but it does not require that you hold the key, at all. The entire amplitude envelope plays from the single Key-On event. (You do not have to hold the key down to hear the whole envelope... thank goodness!)

You can only STORE a Normal VOICE in the Normal USER banks 1, 2, 3 and 4. (512 Total)
You can only STORE a Drum Kit VOICE in the USER DRUM bank. (32 Total).

You cannot store a Normal Voice in the Drum Bank, and you cannot store a Drum Kit Voice in a Normal User Bank. The size and type of data parameters are entirely different. If you check the Reference Manual it makes this clear.

(From Page 54):
Set the destination for storing the Voice.
Select the destination User Bank (USR 1 – 4 for the Normal Voice, UDR for the Drum Voice) and the Voice number to be stored by using the data dial, [INC/YES] and [DEC/NO] buttons. You can also use the [USER 1] – [USER 4], [USER DR], Group [A] – [H], and Number [1] – [16] buttons to specify the destination.

You can, however, create a Normal Voice that contains 8 different Drum or Percussion Waveforms. There is no restriction on what type of sample you use in either VOICE. The "8Z" (8 Zoned) Voices are examples of this type of Normal Voice (8-piece) Drum "kits". These are found in PRESET 8: 058(D10) ~ 080(E16)... you can see/hear how the drums are mapped/regioned to specific areas. As I recall the 8Z "kits" are all triggered by special arpeggio phrases that are designed to trigger these Voices.

And you could create a Drum Kit Voice that contains 73 individual normal instrument Waveforms... although this is not an efficient way to work. In a Normal Voice adjacent keys follow a tuning arrangement such as Equal Temperament - allowing you to play instruments based on traditional scale tunings. In a Drum Kit Voice tuning is per instrument and each instrument typically occupies one Key.

It is a fact that each Element has its own EQ, its own Filter, Amplifier, envelopes, pan position, tuning, routing through the Insertion Effects, etc., etc. a Normal Voice therefore has 8 of these entities - one per Element, a Drum Kit has 73 Elements (so 73 EQs, 73 Filters, 73 Amps, etc., etc.,) and is quite a bit larger in size than a normal Voice.