hi johannes, i tested all the potmeters i have they go into range of 10k till 500k,(the 500 will be replaced by MUCH lower ).With a scope and the converter he showes the full range.
in the image is like you see at the right bottem all the connections.
PC2 PA7 PC3 are 500k potmeters
PA2 = 10 K
PC0 = 250K
PB1 PB6 =100K
hope this is suffiecient information