My Boss back in the 80's bought one and I had the job of restoring it. The worst was jam on the drives and heads (a capstan drive and playback head for each key). The magazine where the tapes hang was full of ferrite dust. We ended up using a DX-7 and a Tascam to make new tapes that were not transparent from so much use.

Since musicians favour particular keys, some notes get more use than others, so in theory you'd rebalance the volumes using a pot for each tape.

A truely unique sound though, something about the analogue process just makes it lovely.