Thank you for sharing your impressions and experiences with the Pi 3 and 4! As mentioned in the article, the assessment of the difference in sound quality is very subjective. It should be noted that the Pi 4 is of course much more powerful than the Pi 3 due to its technical features. One can probably agree that the sound card used is the most important factor in terms of sound quality and the Pi itself has minor influence on that. All the more interesting are experiences like yours, which confirm that there is a difference between the two Pis when using Digi sound cards.