Fixing my MuTron III.. and IC question

[tobias]

My uncle gave me his old Mutron III (yes!) but it has some problems. I have been trying to test it using an audio probe, and I think part of the problem maybe an IC that went bad. It's an opamp called rc4558p. Does anyone know where I can acquire one of these, if they are still available, or could you recommend something comparable?
Thanks in advance and cheers,
Tobias

[rubix cube]

You can get JRC4558 from small bear electronics online.  It's only a standard dual opamp though, so just try a more common one, like TL072.

[tobias]

thanks!
t