Here are two 'Bert van der Wolf links' you might find interesting:
https://www.audioaficionado.org/showthread.php?t=45800
https://www.audioshark.org/manufacturer-events-demos-100/our-visit-northstar-studio-netherlands-16460.html
https://www.audioaficionado.org/showthread.php?t=45800
https://www.audioshark.org/manufacturer-events-demos-100/our-visit-northstar-studio-netherlands-16460.html