The knobs should have no limit (so not a traditional analog pot). Instead they should turn indefinitely in either direction, with a cc turn sending a -1 and a cw turn sending a +1.
Any tips about where to look (manufacturers, suppliers) for such products would be appreciated.
the component that You are searching is a Encoder, similar to potentiometer but
inside there is a small contact with space one by one (ON-OFF-ON) the use of this componente is data encoder digital.
bye..