UR 22 Spare Knobs

We’ve been fortunate to have 20 UR 22s attached to computers in our school music dept over the last few years. They have proved to be extremely robust and reliable. Unfortunately one or two of the knobs have recently gone missing. Is there anywhere I can order some replacements?

Thanks for your help.

Best to contact Steinberg support directly (preferably by phone) as this forum seems absent of a moderator.