If you have one of these in a cupboard somewhere..
Then you could go to circuit
and turn it in to one of these...
Apparently, the insides of a freebass is
the same as an MAM MB 33
I am not sure about this - my MB33 mk2 sounds
different to the Freebass.
Plenty of other mods on the site that could add a
new dimension to a tired sounding synth.