Hello: I’ve had this synth for quite a while with servicing from a tech who worked for Sequential. Over time the keys have gotten very loud with clicking upon release. When I asked about this, the technician said that’s just how it is when synths get old and that maybe it could be fixed with a Fatar action. I’m thinking there must be something in there to replace that would cushion the release. Anyone (1) familiar with this issue; (2) have a solution that a user (as opposed to a skilled Tech) could implement.
That’s the key bushings hardening up with age. They are little rubber pieces that go beneath each key to dampen the impact against the keybed chassis. There aren’t replacements for the Prophet 600 as far as I know but people have had luck with using heat shrink tubing. It’s hard to say how permanent of a solution that is but if you google “prophet 600 heat shrink” there’s a guide showing how they did it.
Fatar is a make of keyboards (they’re used in modern Moog, Sequential and many others) and it is possible to retrofit them into an older keyboard but usually this requires some modifications to the keyboard and synth.
Travis: This is not a key bushing issue, as there are no bushings on the 600. I just took it apart. There is a felt strip 1/8" thick and 1/4" side glued along the rail. Each key, mounted on a spring clip, nests on the felt. I’ve tested it and now know that all I need to do is replace the strip. I am pretty sure–and will know in about an hour – if pre-made weather stripping will do the trick. If not, I will order a felt strip from a piano supply house and glue it on. Thanks for your thoughts.