How to achieve this black grainy gradient background?

[alexm83311464]

Hey all,

Would love to know how to achieve the background below? 

Many thanks

[Chuck Uebele]

Have you tried to apply the noise filter set to monochrome to a gray layer?

[Chuck Uebele]

With this I used noise set to monochrome, upped the grain. After I applied it, I upscaled the image 300%, then added some curve layers to adjust.