I am going to re-record an album where D-50 was used, and buying a sample pack seems more affordable than buying the keyboard. Budget is tight for this people. The sound need to be as good as the original. I don’t yet know of the patches used, must it is one or more of the strings, and pads. One sound might be a soft warm lead sound.
 

Seems there is a soft-synth, but it seems you need some hardware or at least expensive subscription. I hope for something like Kontakt samples or Komplete synth.
 
Here is the Roland one:
https://www.rolandcloud.com/catalog/legendary/d-50
 

https://www.uvi.net/en/vintage-synth/synth-anthology-ii.html 

PinkNoise DeepFlight 2
http://kontaktbanks.com/kb_deepflight2.html
There was also a special UVI library called Synth Legacy with some D-50 sounds, but the PinkNoise one goes deepest (and lowest at $25).

Wow. Thank you guys. Both seems Incredible.

I've got a working D-50 with the original factory patches and a second set of additional factory patches. If you have MIDI for your synth parts and we could figure out which patches were used, theoretically I could record the audio tracks for you. Of course, I'd have to know more about the scope of your project and how much time would be involved. . . .

henkejs
I've got a working D-50 with the original factory patches and a second set of additional factory patches. If you have MIDI for your synth parts and we could figure out which patches were used, theoretically I could record the audio tracks for you. Of course, I'd have to know more about the scope of your project and how much time would be involved. . . .

Thank you. That i sa good idea.
I will lett you know when I know more from the band.

I believe the Roland Cloud is free for 30-days.
You might want to give that a whirl.
 
Bounce the D50 tracks as audio.
If you decide to cancel... you've still got access to those specific tracks.

Jarsve
I am going to re-record an album where D-50 was used, and buying a sample pack seems more affordable than buying the keyboard. Budget is tight for this people. The sound need to be as good as the original. I don’t yet know of the patches used, must it is one or more of the strings, and pads. One sound might be a soft warm lead sound.
 

Seems there is a soft-synth, but it seems you need some hardware or at least expensive subscription. I hope for something like Kontakt samples or Komplete synth.

Here is the Roland one:
https://www.rolandcloud.com/catalog/legendary/d-50

Here is an interesting discussion about D-50 emulations.  https://www.kvraudio.com/forum/viewtopic.php?f=1&t=420219&hilit=D50
 
Some seem to blame Roland for keeping a tight grip on the samples used.
 
The D-50 soft-synth emulation now offered by the Roland Cloud appears to be the real deal, with all the original presets.
 
I must say first that I am not a fan of subscription plans.
 
But since I have a hardware Roland JV-1080 rack, I would love to get my hands on a soft-synth version.  So I looked into the Roland Cloud subscription thing, and that may be a way to go depending on a few things...
 
1. Free 30 day trial, no obligation.  Full access to every instrument in the collection.
2. $19.95USD per month to subscribe.
3. You do not have to subscribe for consecutive months.  Can be stopped and re-started.
4. After 12 months accumulated subscription time, you will be given a free perpetual license to one instrument that you select from the collection.  https://www.rolandcloud.com/yours-loyalty-program
 
So for your project, you could do the first month free, and if you still needed more time with the D-50 sounds for your tracks, you could rent for additional months, ala carte, as/when needed.

JRR has UVI Digital Synsations which includes a D50 for $20 at the moment. Might be worth a look.

https://www.jrrshop.com/uvi-digital-synsations

Yup and you get a 25GB sample library to go with! 
 
But that's probably the cheapest way to get those sounds, other than borrowing an old synth from someone.