Hello Loungeclaus,,
I assume you're referring to the 15-second audio demos that are included in the details of each instrument in the instruments database on our website ( https://www.hauptwerk.com/instruments/ )?
I've just checked the entries for those particular sample sets (a.k.a. 'instruments'), and it appears that they don't currently have any audio demos included. I suspect that will be because the makers of those sample sets hadn't actually sent us audio demos for them, but I'll verify.
However, if you use the 'Visit vendor's website' link below each of the instruments then the makers of the relevant instruments will usually have demos for them on their respective websites.