I have a MK1 series DA7 - probably a good 15-17 years old now... Owned since new. Haven't used it as much in the last 5 years or so, but starting to again... Now to the problem. Several of the "rotary pots" such as the balance control - level for the aux send etc. don't operate/change levels very smoothly anymore - I can turn and turn and don't get much level adjustment out of them (at least very smoothly) like they used to... Before I tear the unit apart, has anyone experienced this issue and if so what is the best way to service/clean the pot? Compressed air maybe? I do have some Caig cleaner that I would used on Analog type pots, but didn't know if these pots are true analog pots (don't think so), or some sort of digital pot with a photo eye or hall effect type encoder (my guess). Anyone?