I am a little skeptical, perhaps worried, about Yamaha fully supporting this stage board. By that I mean in the way of massive voice expansion. Sure they will refine and correct and improve it but how much they will expand it might be an issue. I owned many of the Tyros series & then the Genos and had purchased almost every expansion pack available over those years. I sold my Genos because they completely stopped adding expansions and differed to other 3rd party folks. I have a friend who has the same boards as I do and he never once expanded it as he has zero interest in it. Expansion is one way or the other, you must have it or either you don't care about it and if Yamaha doesn't make money then they become disinterested. I guess the YC61 expansion will depend on sales and how the demand goes & market competition. This board costs a lot more than the MODX-61 so perhaps good expansion is coming. 3rd parties can't load new voices into these type units can they? Obviously voice programs will be available. Being classified as a stage board I know absolutely nothing was done for the CP1 and it costs $6K. Different technology I understand. One indicator I need to research is how many new voices were added to the CP73/88 since release? See below: It appears only (1) thus far providing (3) pianos. Yamaha will hopefully keep in mind on the YC61 that we're cross-over organist, synth enthusiasts, etc. and not just a stage performer wanting 10 more pianos. Gives us everything please including an authentic slide guitar.

David...the good news is that the CP 73/88 had 4 voices added with the 1.1 update and 30 voices with the 1.2 update....and as you note 3 voices with the 1.3 update.

https://usa.yamaha.com/files/download/other_assets/7/1243337/cp88_cp73_en_nf_c0.pdf

The bad news is almost all of the 30 new voices added for the 1.2 update are already on the YC. One of the interesting features of the YC is the FM engine. With that I assume voices can be added with some programming not sampling....and there's always the possibility that we will get access to that engine via an outboard editor...hard to imagine they put that in just to create 20 or so fixed voices. In the meantime I'm learning how to program on the Arturia DX7V to be ready...

I think the only sampled sound category that's not currently sufficiently represented in the YC IMHO is real vocal choruses...a couple ooo's and ahhh's...maybe "Tape" (Mellotron) versions like the Tape Strings voice. Other than that...sure I'd love more voices but it's pretty amazing what you can create with what's already on there. Every few days I try to take an hour or two and just get lost in the board to see what can be squeezed out of it...and there's a lot. Notwithstanding I am anxiously anticipating the first major OS update to see what new voices, features and adjustments they conjure up.

Yes I didn't mention the FM here but I have in other posts. The YC FM capabilities remain to be seen what was implemented under the hood & how it can be accessed. Montage just released an update with Smart Morph for FM-X. Perhaps we can get something like that using a device connected but who knows.

For me, for stage purposes, the sounds on YC61 are just about perfect. Maybe add a couple more Rhodes/Wurli sounds; a little more tweakability in the effects.
The only thing I believe this board actually NEEDS is a better rotary speaker sim. There are good controls for it, and I love the overdrive and Speaker Noise, but the rotary itself is just awful, in my opinion.

I think the most important thing is the frequency separation for horn and bass rotor. Originally at approx. 800 Hz